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xairflyer
01-05-2004, 07:33 PM
After a couple of months looking, reading and learning about home made CNC machines, I started cutting out my 1" MDF machine today.

As I found other guys threads so interesting and useful I thought I would complete a build diary myself, and if a new person gets one piece of information out of it for themselves then it will be worth while.
Decided my first machine would be the learning platform and I will use simple construction and electronics.


My mate brought his Circular saw with a new MDF cutting blade and we cut everything out lovely and square.

The base is 36" wide x 33" deep, it has a fixed gantry with a table size of 24"w x 16"d.
I think I should have about a 20 x 12 cutting area.

I am using 1" dia stainless tube with a ground finish for the rails and bought a load of abec9 bearings on ebay.

I have three steppers, 1A, 1.2A and a 1.35A all unipolar nema 23 size.
Came across extremly cheap driver board from http://www.kitsrus.com/ (although I bought mine from the UK distributor.)
The K179 unipolar driver board kit was only £9.95 works great had my motors on the bench last night buzzing away.
The board has a manual control of speed and direction so is great for setting up without a pc connected.

Going to use a ATX PSU at 12v and some 6R8 resistors.

I do have some nice new in the box vexta 266 127 ozins motors that I bought from a guy, but I intend to keep them for the next one !

Don't have any fancy cad drawn plans of my machine all on bits of paper. I will see if I can post something to let people see the design.

All for now.

cncadmin
01-05-2004, 08:05 PM
Can't wait to see how it comes out! Keep us posted.

balsaman
01-05-2004, 08:33 PM
Looking forward to seeing it. Good design for a first machine. Moving Table is simple and acurate. Also nice size.

Eric

xairflyer
01-06-2004, 11:31 AM
Thanks for the replys.

Not having figured out how to draw with Autocad yet I done this in - Don't laugh ..... MS Word.

I'm one of those guys that does everything in word.

Hav'nt drawn the Z axis, but you will get the idea, actual machine will be rounded in places, but that is more difficult to draw !!

Might use some linear slides for the Z if I can get them at the right money, if not I will just go with the same pipe idea.

Hopeing to have it together (minus pipes) like this tonight.

http://www.esatclear.ie/~xair/my cnc.jpg

Only just figured out how to post an image, thought you could just upload it to the forum.
The FAQ don't have much info on how to do this.

balsaman
01-06-2004, 12:11 PM
You can upload it. Click "browse" which is left of "attach file", then browse for the picture.

Eric

xairflyer
01-06-2004, 01:58 PM
I never saw a browse button, only thing was a IMG button then I typed in the address of the file I uploaded to my web site.

chuckknigh
01-06-2004, 02:10 PM
That was the problem...it seems to want a picture from your local hard drive. It actually uploads the image onto the server, and hosts it locally.

-- Chuck Knight

balsaman
01-06-2004, 02:13 PM
Look at the bottom under your message (while you are posting a reply). There is "attach file" and "browse".

E-man

dlenox
01-06-2004, 05:38 PM
what is the difference in the abec bearings, on Ebay I see
abec-5, abec-7, abec9???

HomeCNC
01-06-2004, 05:51 PM
Look at the bottom under your message (while you are posting a reply). There is "attach file" and "browse".

Eric,

This is always the confusing part for a new poster. You will not see the "attach file" if you use the "quick post" at the very bottom of each thread. You must click on the small button at the bottom of the last post's message that says "Post reply" Then you will be taken to a new screen with all the bells and whistles :D

xairflyer
01-06-2004, 07:35 PM
Yeah I see it now Eric don't know how I never seen it before !!

Anyway, been out in the workshop all evening/night (midnight here now).

Got the two end rails and the gantry sides and front screwed onto the base.

Takes a fair bit of time getting it all marked out, and drilled accuratly.
I have a vertical drilling guide for my cordless drill (like a plunge router idea) so I was able to get all the holes nice and streight.

Decided to go with the tapping idea.
As I was going to use 6mm metric bolts I found the best drill size for the mdf was 4.8 (3/16").

As I drilled each hole I dropped a AN3 (3/16") bolt into each hole to keep it square.
I then drilled out the base 6mm and countersunk the holes for the allen head C/S bolts.

I tapped each of the holes, using a machine tap in a slow cordless drill and it worked great. I then ran thin cyno down the holes into the threads.

So this is the stage I am at. Need to turn up some inserts for the ends of the tubes (rails) and make the adjusting blocks.

What is the best material, I was thinking about nylon or similar, don't think even the 1" mdf will stand up to it.

xairflyer
01-06-2004, 07:39 PM
Don't know a lot about the bearings but I do know that abec 9's are water proof, 7's are classed as sealed and I would think that the 5's are probably just shielded.

I have both 9's and 7's and the 9's are definatly the better.

ger21
01-06-2004, 08:00 PM
The different ratings have nothing to do with seals or shields. And I'm pretty sure that none of the abec 9 bearings (skateboard bearings, anyway) on Ebay arer waterproof. The difference is, the higher the number, the tighter the tolerances are. Generally, if you're gong to use them on some type of tubing ala JK, it won't really matter all that much. But if you can get abec 9 bearings on Ebay for $5 or so, no reason not to get the best if you're paying the same price.

Gerry

balsaman
01-06-2004, 08:24 PM
What gerry said about bearings is correct.

Nice job so far AirX. Use Plastic, PVC, or aluminum for the adjuster blocks. MDF is not tough enough. I have heard you can buy a cheap plastic (nylon?) cutting board from wallmart that will work for those and some other plastic parts. About 1/2" thick.

E-man

xairflyer
01-09-2004, 08:52 PM
Got my table made up today with the angle down each side and the bearings fitted.

I bolted the angle to the MDF with 6mm Stainless Hex bolts. Four underneath and three on the side.

Surprising the time it takes, just to mark and drill the angles, so as to get the correct distances for the bearings, as they sit on the rail at 90 deg to each other.

You can see in the pic the black engineers marking ink (well a large permant marker !) used to see the lines on the alloy as I marked everything with the height gauge.

The time I have spent on getting everything as accurate as possible I started to think I should have went with the all aluminium version now, but I am determined to build a MDF machine, as simple and cheap as possible.

The alloy machine can come later.

Got my end plates drilled as well for the tubes (rails) and I am picking up some 25mm (1") nylon tommorrow to make the "four jaw chucks" for setting up the rails.

My local steel stockist cut up some 2" x 1" box section to my requirements today, so I can start welding up a frame/table next week to set the machine on.

Fitting the stepper and lining up the drive screw has got me thinking.
What I was going to do was mark a spot as accurately as I can on the drive plate under the table, and then drill a larger than the drive screw (5/16") clearance hole.
Fit my drive nut to the drive screw then bolt this to the plate, does this sound correct ?

What would be the best method of connecting up the 1/4" shaft to the 5/16" drive screw. ?

xairflyer
01-09-2004, 09:02 PM
Forgot to add in last post, the bolts I used for the bearings were socket caps (as you can see), 8mm x 40mm but the good thing was they had a plain shank of approx 8mm long which was a perfect surface for the inside of the bearing.

I fitted a thin Stainless Steel washer each side of the bearing then tightened up a S/S Nyloc nut against it. No play or slop at all.

The bolts are a bit long, and I have them fitted with std nuts temporarily at the moment.
I am on the look out for a S/S version of the bolt, about 10mm shorter, but might be harder to get the plain shank.
Good thing about stainless is you can cut it without it rusting !!

DaSigntist
01-09-2004, 10:26 PM
Looking Good!

If I might ask.....Why the stainless steel on any part?
Seems like an unnecessary cost.

"Fitting the stepper and lining up the drive screw has got me thinking.
What I was going to do was mark a spot as accurately as I can on the drive plate under the table, and then drill a larger than the drive screw (5/16") clearance hole.
Fit my drive nut to the drive screw then bolt this to the plate, does this sound correct ? "

What I did was mount one side and run the axis down to the other side to match it.

"What would be the best method of connecting up the 1/4" shaft to the 5/16" drive screw. ?"

If you referring to the motor to the drive screw I gut got some reinforced rubber tubing with hose clamps.

chuckknigh
01-10-2004, 12:19 AM
On mine, I got some reinforced air tubing, and actually tapped the 1/4"ID tubing with a 5/16" tap.

I screwed it in, and then slipped in the 1/4" shaft -- some worm clamps to hold everything tight, and it worked great.

Or, you can get some of those flexible couplings from McMaster-Carr...they have a standardized mating connector at the center...the two ends can have different sized couplers.

-- Chuck Knight

xairflyer
01-10-2004, 07:07 AM
The reason for the stainless is I hate rust, being from an Aviation background it is always a no, no.

The climate in Ireland would be much more damp/moist and even in a workshop untreated steel items don't stay shiney for long.

The other reason is I generally have loads of stainless nuts, bolts washers about as I use them in my buisness all the time.

Not much difference on cost, I can get 100 M6 nyloc nuts for only about €2 more than standard ones.

xairflyer
01-10-2004, 07:20 AM
Great idea chucknigh, I will use that. Can't believe the stuff I am tapping these days !

On the tapping front, Yesterday I could'nt find my 6mm machine tap (located later in my pocket !) so I used a standard hand tap as I only had one hole to tap.

Well Massive difference the quality of the tapped thread was nothing like what I got with the machine tap.

The reason I went with a machine tap from the beginning is I know from experience, if you want to tap without having to back off to break "the chip" like normal, then a machine tap is the way to go. The flutes are designed to take the chip/swarf (in the case of steel) out in one piece, so you can go streight in and streight out, perfect for tapping with a cordless drill.

So my advise is, when tapping MDF get yourself a machine tap rather than a hand tap and you will get perfectly tapped holes everytime and easy to using a cordless drill.

Mr.Chips
01-10-2004, 08:39 AM
Thanks Xairflyer, for the tip on "Machine Taps".

Would a machine tap also reduce the possibility of tap breakage when tapping alum? I'v broken a few taping alum, seems the chips stick together and jam, even when backing up ever so often.

Hager

buscht
01-10-2004, 11:09 AM
Mr. CHips, You might want to use Tap Magic cutting fluid for Aluminum. It will solve your chip sticking and jamming.

buscht
01-10-2004, 11:13 AM
xairflyer, When screwing MDF together I think the best fastener is a confirmat screw. Here is a link that shows how one guy uses then in cabinet work.
http://www.norrod.com/shop/screws/
You don't need that fancy drill bit, but you need a clearance hole (8mm) for the the shoulder and a pilot hole (5mm) for the threads.
This eliminates the tiring tappping of MDF and holds fantastic.

xairflyer
01-10-2004, 01:16 PM
Yes I have used these before they are common to flat packed furniture you buy at DIY stores.

Tapping should not be tiring if you use a cordless drill !!

davesaudio
01-10-2004, 06:45 PM
The K179 unipolar driver board kit was only £9.95 works great had my motors on the bench last night buzzing away.

good deal those, wish I had seen those before I started my homebrew version. its pretty much just the cost of the parts...

avsfan733
01-10-2004, 09:24 PM
Originally posted by buscht
Mr. CHips, You might want to use Tap Magic cutting fluid for Aluminum. It will solve your chip sticking and jamming.

Tap magic is incredible stuff. Personally i usually back the tap all the way out of the whole and blow it out every quarter inch or so with aluminum

I spent the last week cutting and tappin 4140 and was amazed at how well it actually tapped, so much easier than i expected

xairflyer
01-10-2004, 09:52 PM
Mr Chips,

Machine taps work great in all materials, and by their design, are not meant to clog up. But a tapping fluid like buscht mentioned is always recomended as well.



Davesaudio,

You should also look at the K109 kit it uses the UCN5804 chip and has half step as well. £14.95stg.
It is Limited to a 1.25A motor in it's out of the box setup.

I have ordered one to play with, as I want to build a pan mount for my CCTV camera.

xairflyer
01-11-2004, 09:36 PM
Started making up my 4 jaw chucks today for the rails.

Only material I could get (without having to wait a week) was 1" nylon. Sorry I never waited !!!

I decided to drill out the clearance holes for the 1" tube and used a 1 3/8" hole saw.
Nylon is a pain to cut at anything faster than you can do by hand.
It heats up so fast, I was cutting at the slowest speed on my drill press, and it still kept heating up, clogging the cutter, even the coolant was bubbling with only small cuts.

Eventually got four holes cut for the x axis blocks and then I tried to cut them into 3" squares (as I left them in one piece for easier drilling) I decided to use my jigsaw as I had broke the blade in my bandsaw last week.
Tried all different pitch sizes of blades and all it did was melt !

Ended up Cutting it with the hacksaw which cut it fairly well and easier than I thought.

Note: Best thing to cut nylon is a hacksaw, bandsaw would be ok to if you have access to one.

After all that work I Still have to clean them up, and probably still won't get that good of thread when I tap them.

Would not recomend the use of standard nylon, especially that thick, Delrin is a far better material.

I could have made them up in 1/2" alloy plate in half the time, but I did'nt really want to mix alum with the wood if possible.

I am going to make some out of 1" MDF for the y axis just to put to the test. I think with the great thread my machine tap makes, along with the thin super glue I will have just a good of job as the nylon ones.

Time will Tell !!!!

balsaman
01-11-2004, 10:20 PM
The CYa will help a lot with the threads. It's a trick only a model airplane guy knows!

Eric

xairflyer
01-12-2004, 07:12 AM
I think being a model and full size flyer is what gave me the motivation to build one of these machines.

I can see lovely ribs etc being spat out, as fast as I can stick them together.

I want to build a 1/4 scale R/C model of the aeroplane that I Distribute and fly.
The wings are tapered and swept back so it means a lot of cutting by hand.
This will be my first project when the machine is up and running.

I have a lot of little things I want to make for the full size version's that I have to make by hand now.

creative_mind
01-12-2004, 01:24 PM
xaeroflyer,

You have a beautiful flyer in the picture. Do you have the plans for it? I'm interested in building one myself.

xairflyer
01-12-2004, 01:42 PM
It is only available in kit form, we both sell kits to customers and build for them.

Construction is all aluminum tubing and the covering is Dacron (polyester).

xairflyer
01-17-2004, 08:32 PM
Got my steel framework made up to sit the machine on.

Made the whole thing out of 2" x 1" box section, need to paint it now with hamerite.

Not been too happy with the nylon blocks for the four jaw chucks, firstly because of the work it took to make them, and second because I am not that keen on the finish or thread quality.

Decided to make some up out of 1" mdf to try out and I am really pleased with the result.
I cut the clearance hole in the middle, with a 1 1/4" flat (spad as we call it) wood bit, and the finish of the holes is lovely.

Made big discovery on the tapping front.
I had this flash of an idea lying in bed, and decided to try tapping the holes with a Roll tap.

The difference is (hard to explain) the tap dos'nt actually cut a thread, it makes the thread by squeezing the material into a thread as it goes, so instead of material being removed (swarf) it push's it into the last thread.
These taps are normally used for tapping holes in extrusions punch out of a piece of material in order to give it sufficent thickness to actually have a thread. (a 1/8" thick piece of material would not have many threads, but this can be doubled or trippled by extruding it.

You could'nt use one in normal circumstances for tapping steel as it would jam or break, but wood and especially MDF is perfect for it.

I put it to the test and the threads are actually HARD, this is due to the squeezing of the wood to form the thread.
With the thin cyno, and then re tapped again after about 2hrs (won't get bits of glue stuck on your tap, if you leave it a while to harden) The thread quality is that good, my mate thought I had fitted inserts into the mdf.

The moral is for tapping MDF you want to get your hands on a Roll tap.

So I am scrapping the Nylon 4 jaw chucks and making them all
(x and y) out of MDF, as you can see from picture I have drilled all the holes in a 9"x6" piece ready to be cut up into 3"x3" squares.

The nylon block dos'nt even look as good !

Mr.Chips
01-17-2004, 09:43 PM
"Roll Tap" never heard of that one. But the principal sounds very sound with MDF. Is this tap available in the US?
I made my first srt of blocks out of a thick cutting board and it was a mess cutting them the material wanted to melt and difficult to clean up. Finally decided not to use them and gang drilled the end plates. Put the base together today will find out tomorrow when I mount the movable table how far it's out. Hope they are parallel and level, time will tell.

Hager

xairflyer
01-18-2004, 05:25 PM
I agree nylon/chopping board material, is a pain to work with, I milled up the sides of the blocks I cut, but not eveybody has a mill in the garage, so that is why I favoured MDF, as a test.

The name "Roll tap" could be an engineers term for a "fluteless tap" try that name and see how you get on.

They are in my RS catalogue, not that cheap as they are a specialist tap, but for tapping MDF brilliant.

In the RS catalogue they state "they produce threads not by cutting, but cold forming material displacement"

TopSpin80
01-19-2004, 10:04 AM
I'm using Forstner bits for all my holes... MDF and cutting board material. They leave a flat bottom hole too incase you don't want to go all the way through. The hole is a lot cleanter then the hole saw holes. I drilled these bearing blocks with them, and the holes they leave in MDF are incredible.

Ernie

Hobbiest
01-19-2004, 02:20 PM
Forstner bits have the bonus of making round holes as well, instead of the slightly oblong holes from a twist bit. Bearing blocks look great. What are the step sizes? 7/8" and 3/4?

TopSpin80
01-19-2004, 08:56 PM
yea they are 7/8 and 3/4 the bearing isn't really tight in there, but there isn't much slop either.

Ernie

Hobbiest
01-19-2004, 09:59 PM
should be tight enough once you get your washer on there. Another idea...use a fender washer that is just small enough to grip the outer race of the bearing, and drill two holes in the edge to mount it.

ger21
01-19-2004, 10:24 PM
CMT makes 22mm forstner bits, for about $15. That is what those bearings are, right?

Gerry

TopSpin80
01-19-2004, 10:29 PM
Looking at theses things I don't really think anything needs to be done to them as far as the tightness. I do need a drilly press though, to make the holes straighter. I had a freind that had a small mill he wanted to sell. If I can find his number and he still has it I'm gonna buy it.

xairflyer
01-20-2004, 06:47 AM
I have been looking through various posts, on lead screw (drive screw) fitting and I can't seem to figure out why a thrust bearing arangement is used for the end of the thread.

I was going to mount a rod end type moveble bearing (to allow for any miss-alignments) to the end plates and just stick the threaded rod (5/16") through it.

Can anybody explain what I am missing, or not considering ?

Stevenpats
01-20-2004, 04:09 PM
The thrust bearings keep your leadscrew from moving back and forth when it accelerates or decelerates against the table load. I use 1/2"-13 threaded rod and 1" delrin nut for drive. The rod is turned down on my lathe to the ID of the thrust bearings,and sandwiched, I did not use a tensioning arrangement. Tensioning the leadscrew would have helped a bit with whip, I get a bit with rapids, when the table is at far travel. I did leave about 3/4" of excess rod out the end of thrust bearing, enough to thread with a die for a tensioning nut/washer arrangement if I feels its needed.
Steven

Hobbiest
01-22-2004, 09:19 PM
I hear mcmasster-carr has thrust bearings with 3/8" ID and a flange on one end. Haven't checked it out yet but they prolly do. May even have different sizes.

xairflyer
01-22-2004, 11:16 PM
Got the X axis/table all setup last night. Takes a bit of time to get everything right.

I first got the base of my machine on it's stand perfectly level in all axis, then set the table in and got the rails parallel (ish) so that the table ran freely with the side bearings touching at all places.

I then removed the table and leveled each rail fore and aft, then from one rail to the other, and back & forward, and back & forward as each adjustment effected the other.

I the checked the parrallel'ism with a large verner, then back to the level of the rails again !!
Eventually I got it that I was fairly happy.

Re fitted the table and checked it for level on the rails. Only one bearing was out, a bit too low, which caused the opposite bearing to sit above the rail i.e. not touching.
Looks like it was worth while spending the time marking out the bearing positions on the angles very accuratly.

Turned up an insert out of nylon to fit the ends of the tubes, just to stop the adjusting bolts from disforming the tube. Not that the stainless pipe I used would be easy to squeeze, but I though it would look better too.

Mr.Chips
01-23-2004, 08:58 AM
Just a word of caution.
MDF is very dense but it doesn’t have very much linear strength to support it’s self and will sag and flex very easily over relative short distances. Neat looking table just be sure you have a couple of supports under the machine to keep the base plate flat.
I’m building a movable machine also and the table is 24” wide. When I installed it, it was flat, but just over a few days it has started to sag just under it’s own weight. Mea by it’s the humidity here?
I found a used piece of 1” delrin and will replace my table with it. Before I found the delrin I was thinking about adding some kind of metal brace for added rigidity.

Torsion Box
http://www.diynet.com/diy/shows_wwk/episode/0,2046,DIY_14350_26946,00.html
Another way to eliminate the sag would be to make a torsion box type table. But this would make the table thicker.
Anyway it’s a thought.
Hager

balsaman
01-23-2004, 12:16 PM
AirX,

Slot the hole in the alum. angle so you adjust the offending bearing and retighten.

E-man

Hobbiest
01-23-2004, 12:54 PM
Don't know about \delin, but UHMW is similar and flexes and contracts readily with changes in temp. Why not get a cheap piece of aluminum angle and cut into pieces to reinforce?

Hobbiest
01-23-2004, 01:00 PM
Thatdelrin is probably as expensive as aluminum plate .25!

xairflyer
01-23-2004, 09:05 PM
Don't think I will have any sag problems, the MDF is 1" thick and it is sitting on a frame of 2"x1" steel box section with a support every 9".

Balsaman that's what I done to adjust the bearing.

Mr.Chips
01-24-2004, 12:44 AM
The Delrin was free. It is 1" thick and has lots of 1/4" holes, it was to be a vacuum table in a lab but they made a mistake during machining and it was trashed.

Nothing to loose, had only to cut 1" off the width for it to fit my table. And I could not make it flex.

Xairflyer,
You wont get any MDF flex on that table.

Hager

Hobbiest
01-24-2004, 02:38 AM
Ok, so the delrin will be on top of the MDF? What I was talking about was unsupported lengths of plastics warping like crazy, but if it has an MDF backbone that it is screwed to it should be fine. But why use the delrin if in fact you are keeping the MDF too?

Mr.Chips
01-24-2004, 07:54 AM
Sorry I didn't make myself clear. I removed the MDF table and replaced it with a piece of delrin that was 1" thick.

Are you sure this material will "warp like crazy"?

It is really rigid, I could not make it flex any by placing one end on the floor and the other end on a 2X4 and standing on it. 210Lb. The 3/4" MDF could be flexed by pressing on it, without standing on it.

I'll try it and if it doesnt work out, I'll cut it up and make antibacklash nuts out of it. Can get alot out of a piece that is 1" X 24" X 30" even cutting around the holes.
Hager

Hobbiest
01-24-2004, 03:08 PM
But then you would have to build more machines! Like I said, I don't know about delrin specifically, but UHMW which is similar is very thermal sensitive in large pieces. Anything more than about 3/4", and it swells and contracts. I have a 2" by 3" by 3ft piece, and it is very solid, yet always has a different profile! Anyway...just my two cents.

gmfoster
01-24-2004, 04:45 PM
I don't know if Delron warps ut UHMW sure does.



Garry

xairflyer
01-25-2004, 09:39 PM
Have the x axis motor fitted and the table moving under it's own steam !!

Tricky job to get the Delrin nut/plate fitted under the table.

I first screwed a 1" x 2" x 5" block to the bottom of the table in the middle. I had already worked out that the lead screw would be approx 1" below thw table so I drilled a 13mm (1/2") clearance hole to allow for any slight misalignments.

I made a delrin plate (no antibacklash for now) and pre drilled two holes in opposite corners for screwing to the support block.
Screwed on the delrin nut, and refitted the table.

Screwed up the plate until it came in contact with the support block, and very difficultly (as there is only 2 1/2" under the table) managed to clamp the delrin plate to the support block.
I then removed the screws holding the block to the table from above and lifted the table out of the way.

All I had to do then was unscrew the threaded rod and drill my holes.
A tricky job, but it was worth it as everything runs nice and true.

I rigged up my test driver board and I am not getting much speed, with a 3.9v 1.35A motor running on 12v with two 6R8 res (6 wire) turning a 8mm (18tpi) screw, the best I get is 10" min.

How can this be increased, I was thinking of changing to 10mm or 12mm all thread ?

Will a larger 2A, 3.6v, 127ozins torque motor go any faster ?

xairflyer
01-25-2004, 09:42 PM
Does anyone know how to attach more than one picture in each meassage ??


Started fitting my Y axis

cncadmin
01-25-2004, 09:45 PM
Originally posted by xairflyer
Does anyone know how to attach more than one picture in each meassage ??



This site can't do that right now but the new one will.

balsaman
01-25-2004, 09:47 PM
Need more voltage for more speed. What driver board are you using? 10-12" is normal for a 12 volt supply.

Eric

Hobbiest
01-25-2004, 11:48 PM
check out Steve Manzer's site here, he is getting double that speed with 20tpi rod.
http://www.angelfire.com/ego/stevenmanzer/CNCMachines.html

xairflyer
01-26-2004, 07:47 AM
The driver board is the K179 kit basicly the same as the piker.

I hgave altered the value of the pot and limit resistor (used for manual control, not connected to PC) and when I go too far, the motor just buzz'sssss

I assume the motor can only go so fast.

Does the speed vary in motors ? I am wondering if my 2A 127 ozins vexta 266-2b motors will go any faster.

Hobbiest
01-26-2004, 11:27 AM
can't find any numbers on the website, but my 80 oz/in motors are capable of 120 rpm so I can't see yours being slower. Check that your screws are not binding at either end of travel, as that has in the past caused just buzzing with no turning. You'd have to turn 400rpm to get 20 ipm, right? Huh...don't know how that math works out then, cause Steve Manzer is getting 20ipm and I think he is useing the the same cheap motors. I'll do some reading on his site today, post later.

balsaman
01-26-2004, 12:10 PM
Higher oz/in does not mean faster unless you go higher VOLTAGE powersupply. 24 volts with the right resistors will double your speed.

Trust me on this one.

Oh, and don't worry for now about speed. Get the machine going first.

Trust me on this one too.

Also, I am not sure how/if you can accel with the setup your using, but that is a factor as well.

Eric

limbo
01-26-2004, 12:20 PM
Balsaman is right, if your drive nut is not causing lots of friction the problem is in your drivers. Get a chopper board, run it at 30V and amaze yourself at the speed you get ;)

John

xairflyer
01-26-2004, 12:33 PM
Now I know that 10" min is normal for this setup I will stick with it. I thought I was doing something wrong.
I don't want to fit a different driver board or bigger power supply, the idea was to make this machine as cost effective as posible to prove the principle to myself.

If I can speed it up a bit with 10mm threaded bar then I might change to that.

I will go with Xylotex board and proper drive screws and all the bells and wistles for the all alloy machine I will build next.
First I want to understand how to get this one setup.

davesaudio
01-26-2004, 08:19 PM
he driver board is the K179 kit basicly the same as the piker.

I wonder if the mosfets are being driven hard enough by the cmos logic at 5volts...

do the mosfets get warm(er) when the stepper buzzes?

the z44s are sufficiently hefty...

xairflyer
01-27-2004, 06:36 AM
Not sure if they get warm as I adjust the pot, until it starts to buzz then back it off slightly so it is at maximum speed.

I measured the 100k pot at this setting and it was about 900ohms, so I increased the in series 1k limit resistor too 2k2 so I can just screw the pot the full way now, just for practicality.

I am using this board (K179) as a stand alone at the moment just for testing, a 4093 is used as a pulse generator.
The values of the pot and series resistor shown in the documentation have been changed to values above.

As I know full speed is a pulse frequency generated by approx 1k9 with the cap fitted (1uf) I will try a 4k7 pot in place of what's there and adjust that to the optimum, that way I will be able to get the motor at it's optimum speed before it buzzes.

xairflyer
01-28-2004, 07:17 PM
Seen somewhere diodes added from each side of the coils to positive, so I decided to add them in and see what happens.

I connected each one first by mistake to the 12v (bypassing the dropping resistors) and the motor ran at the same speed by sounded very rough.

Connected them then to the other side, matching the centre taps, as I am using two resistors (just in case it would make a difference) and the motor ran very very slow.

Realised then afterwards that fitting diodes like this was really for protection of transistors and as I am using fets, it just made things worst.

Any views ?


NOTE I have not shown the diodes on the circuit below, I just attached it to show the ouput.

xairflyer
01-31-2004, 08:14 AM
Been working on the Y axis, as you can see from the pics I used angle and roller bearings again. In order to get the angles nice and square I milled/routed two slots for it to sit in.

Had to also mill out some clearance for the nuts.
Set my rails up first like the x axis, but this was a mistake as I then had to make the spacing piece to fit the setup of the rails, which meant machine the spacer 58.8mm !

Should have made the spacer a fixed demension i.e. 60mm or
2 1/2" and adjusted the rails to suit.

Also got the rails perfectly set up, only to realise, I needed to remove one of them to fit the y carriage !!
Rails needed to be fine tuned again anyway - you learn these things as you go !::D

Hobbiest
01-31-2004, 06:31 PM
Great carriage design...how is the flex in the steel rods though?

xairflyer
01-31-2004, 09:30 PM
The rails are 25mm (1") Stainless Steel tubes with a 1.5mm (.060") wall and are very ridget (can never spell that word).

If I push down on them, I can get them to flex about 0.2mm (.008"). I am going to fit a support block under the lower rail and above the top rail once I get everything setup.

Hobbiest
01-31-2004, 10:36 PM
Are your bearings pre-loaded into the tubes? Just curious, as it doesn't look as though you have any adjustment for the tubes themselves. Oh...its rigid. Gonna go for now...uncle Bushmills is calling my name!

xairflyer
02-01-2004, 07:48 AM
If you about 15 posts up you will see the four jaw chucks fitted to the side plates.

xairflyer
02-01-2004, 09:40 PM
Messed about with the driver board, and now have 12" min with the 20tpi screw.
Going to stick with that now until I get the machine running, will then try 10mm and 12mm threaded bar.

xairflyer
02-04-2004, 09:49 PM
Working on the Z axis, and decided to have a go at making my own bearing blocks for these great simplicity bearings from Pacific.

Main concern was accuracy, as I did’nt want them binding. Decided to go with a mixture of mdf and nylon.
Made the two end plates for the 12mm shafts out of mdf and milled them perfectly square. I put one on top of the other and then used a 12mm milling cutter that I under sized slightly to drill the holes. I clocked up the spacing on the cross slide vice, to have a reference for the bearing blocks.
The 12mm shafts were now a rubber hammer tap into the mdf end plates.

The simplicity bearings have an OD of 22mm and in the manual it shows fitting ‘O’ rings to the groves to allow for slight misalignments which I thought would suit here.
The hole in the bearing block is oversized 0.2mm to allow for this, so I modified/ground a flat wood bit to 22.2mm. These are great for cutting accurate holes.

Made up the two nylon bearing blocks and drilled them like the end plates, with the exact same centers. Holes came out 22.22mm (.02mm oversize less than a thou) I was happy with that.
Bearings were a nice tight fit in the blocks. As I used 25mm nylon I milled down to 20mm to allow for the retaining circlips.
I can see now how the ‘O’ rings work, it is a really good idea, keeping to the manufacturers sizes would be important though.

My two blocks slide really nice up and down the shafts, I still have to fit the router holder to the blocks.

Really glad I went this route, simplicity bearings are cheap and are designed to run on any type of shafting, provided it is true. The cost of the Bearing housings put me off before going this route, but reading mikeschn thread got me thinking.

xairflyer
02-04-2004, 09:51 PM
And the Z axis itself, temporarily fitted to the Y


Note. Nylon block between bearing housings is only a temp spacer.

cncadmin
02-04-2004, 10:03 PM
Looks soild, that should work fine.

Hobbiest
02-04-2004, 11:41 PM
Are you going to have more space between the bearings when the spacer is removed? I would be concerned about flex in the tool carrier without enough space.

xairflyer
02-05-2004, 06:59 AM
There won't be any movement, this is one of the reasons for going with this type of slide.

arvidb
02-05-2004, 03:25 PM
Originally posted by xairflyer
There won't be any movement, this is one of the reasons for going with this type of slide.

Wouldn't the unsupported pipe/rod be the source of almost all of the flex in this configuration? In that case, you would get less flex by putting the bearings further apart.

Arvid

Hobbiest
02-05-2004, 08:32 PM
I was reffering to the vertical distace between the bearings. Seems to me that with the mounting plate on there, the shorter distance will act as a more effective fulcrum, in a 20,000rpm lever. This is why I have been trying to caution people against too long of a z-travel for their first machine. The z is already the hardest part to build (in fact when I am trying one of my new ideas, I usually start with the z, then y, then x), and more travel makes it harder. IMHO.

xairflyer
02-05-2004, 09:03 PM
Picture is a bit deceiving, and spacing of the blocks is not as is, it was the first bit of nylon I lifted !

There are 10" between the end plates, I will space the blocks about 5", with the limit switch's there will be about 4 1/2" travel.

Arvidb is right the Y rails are the weak spot in my machine. I have suport blocks already made up for bottom and top of the Y rails. Don't intend fitting them until I have everything where I want it.

arvidb
02-06-2004, 04:50 AM
Originally posted by xairflyer
*snip* There are 10" between the end plates, I will space the blocks about 5", with the limit switch's there will be about 4 1/2" travel.

Arvidb is right the Y rails are the weak spot in my machine. I have suport blocks already made up for bottom and top of the Y rails. *snip*

Since my last post was a bit unclear: I was too referring to the vertical distance between the bearings, not the distance between rails.

If I understand your description correctly, maybe the end plates will be spaced far enough apart, and the travel will be small enough, for you to be able to fit a support at the mid-point of the Z rails, in addition to the end supports? If you could find room for this, it would stiffen things up considerably.

And if not, and if you are unhappy with the amount of flex when the machine is finished, you would at least have the option of sacrificing some Z travel to get more stiffness. It all depends on what you are going to cut. If balsa I guess it won't matter!

Arvid

xairflyer
02-06-2004, 08:29 AM
I don't think the Z axis rails are going anywhere, they are hardened ground rods and being only 12" long the best deflection I could get by really forcing them was .1mm.

The mdf is 1" and again over this short distance it is very ridged.
Any flex or movement is going to be in the Y axis, I will need to make my support rails, very accurate.

Hobbiest
02-06-2004, 02:19 PM
Sounds like we are all on the same page! BTW...didn't say it before, its looking really good! Can't wait to see it finished and movin'!

xairflyer
02-10-2004, 09:35 PM
Still working on the Z axis, I have scrapped the idea of using the leadscrew/motor combo I got from www.manufacturist.com
due to the low torque of the motor.

Decided the Z could do with a good motor as it does have to lift the z axis and the weight of the router, so I am using one of the vexta 127 ozins motors I had been saving for no. 2 !!

I am using 12mm threaded rod, so I turned down the end to a nice fit in my bearing in the end plate, and drilled the other end for the shaft of my stepper.
The stepper had a hole in the shaft so I done the same in the all thread and fitted a roll pin to secure it to the shaft.

Tapped the 1" nylon block I made for the simplicity bearings with a tap made from the all thread, and it works good.

Need to start painting as I don't want to take this apart again.

Pics to follow, camera batteries were flat !!

Hobbiest
02-11-2004, 01:52 AM
Sounds good! That lead screw would work well for another project once seperated from the motor. It is teflon coated steel, and really nice! It is very unfortunate that the motors are not very strong. We think they were origionally used horizontally, as they seem to work much better that way. Can't wait to see those pics!

xairflyer
02-11-2004, 06:32 PM
I am going to keep the stepper/leadscrew for a small pcb machine I am going to build, it will work ok for that.

Here is some pics.
I am away for a week so the work has stopped.

balsaman
02-11-2004, 07:31 PM
Nice job!

Eric

WOODKNACK
02-11-2004, 07:42 PM
Yes very nice. Very good quality work you are doing there..:cheers:

xairflyer
02-12-2004, 07:01 PM
I have became a massive fan of the flat wood bit. The skate bearing used in the end plate is 22mm OD as you know, so I ground down a 22mm flat bit to about 21.75mm.

I then had a squeeze fit in the end plate for the bearing.

Great bits these, you can as accurate hole as you want with a little of regrinding !

xairflyer
02-23-2004, 07:44 AM
Been away for a week and could'nt wait to get back to finish my machine.

Spent yesterday completing the Z and making a clamp for the router.

The z axis works very well, the 12mm all thread lead screw suits it perfectly, with the 127oz ins stepper.

Still think the Y axis is the weak link in the machine, I am going to make supports for the rails and see how it goes.
I will probably change them down the road for 20mm (3/4") shaft and Simplicity bearings like I done for the Z.

Pictures below show the Z temporarily fitted to the carriage as I am going to paint it before I bolt it up for good.

Also pic below shows the router spinning with the lights ON !!

Konstantin
03-01-2004, 10:23 AM
I dont know if I missed it up thread but anyway.
What are your expectations about precision?

xairflyer
03-01-2004, 02:20 PM
Won't know for certain until I reasemble it all this week as I have been painting. (a lot of painting)

Time spent on the setup will determine how good I get it, If I can't get it within what I expect for this first machine then I will change it. Would expect to get it as good or better than what is normal for rollar bearing machines.

Gus_452000
03-14-2004, 09:29 AM
xairflyer,
that machine looks like the dogs 'whatsits' have you drawn any plans up?
Very very impressed at the design, if you do have any plans/drawings/ sizes I would be very grateful.
Keep up the excellent work
Gus

xairflyer
03-14-2004, 09:15 PM
I do intend to produce a plan, as it is difficult to get any outside the states.

As an update, I have stripped the whole machine and have it all painted. I am in the middle of building it up again, and setting up the rails etc.

Glad I decided to dowel most of it as it has made the reassembly much more streight forward.

Gus_452000
03-16-2004, 11:15 AM
xairflyer
daft question but here goes.
The router is just plugged straight into mains and is not going to be controlled by P.C.? You plug in to switch ON and unplug to switch OFF!
Gus

xairflyer
03-16-2004, 02:46 PM
Yes, but some boards also have a means of controlling that as well.

glenfraser
03-16-2004, 06:33 PM
Yes any type of bits at a good price in the uk is a pain. The price and getting plans steppers and linear bearings etc well every time i look at the US theres loads and at good prices. Keep up the good work on your mill i am just about to start mine.
Mdf is what ill have a play with. I am only working to A4 size for pcb drilling. Iwas thinking of 400mm across and 600mm towards me on the bed in 16mm bar and the same sort of bearing you are using on the rails but slightly different way of using them.
Have some old type 23 70oz steppers 2.25 volts so should do the job. And kellyware software.

Glen

xairflyer
03-16-2004, 08:52 PM
I am going to build a PCB machine as soon as I finish this one, I am already gathering up the bits !

I am interested to find out more on the whole making pcb's process with type of machine.

Gus_452000
03-17-2004, 07:19 AM
xairflyer,
I started cutting MDF today (how heavy is that stuff) and have got a similar design to yourself but I am using solid ground steal shafts bought from RS supplies (I got a free CD from them by sending an email) they have a lot of stuff on there that we can use including stuff like linear bearings, they also do steppers but they are very expensive. I was lucky and got given 4 100oz steppers but there are some electronic salvage yards that strip old machines and sell the bits out of them i.e. steppers etc try WWW.distel.co.uk.
I to will, when I have made this monster make a smaller router board (I plan to use this one to make the smaller one) and plan to use either a dremil or a dc motor for the router.
Best of luck and keep the pictures coming
Gus

xairflyer
03-17-2004, 04:45 PM
Have a look at the self lubricating bushings from rs 243-9710 (20mm size) you can get them in a pillow block as well 217-9805 also the IGUS drylin range 20mm = 311-3480.

I used the 12mm 217-9697 for my z axis with 12mm shafts RS shafting is also not bad value 285-0396 is 1M length of 20mm it is about £22.

I might upgrade my y axis after I have things running.

A dremel will be OK but have you seen the one I am using from B&Q on special at the moment for £29.98 !!!

I posted a thread for it some time back

http://www.cnczone.com/forums/showthread.php?s=&threadid=2814&highlight=b%26q

glenfraser
03-17-2004, 05:01 PM
Ill have a look in there tommorrow. I brought my leadscrew from them. Nice 8mm one from them 98 pence per meter.

Glen:D

glenfraser
03-17-2004, 05:03 PM
I got 608ZZ for 50 pence each. Ahhhh it does pay to shop arround these are 8mm inside and 22mm on the outside. My design uses 30 ish. I brought 50 for that price...

Glen:D

Gus_452000
03-18-2004, 03:34 AM
I must say having looked at the router you posted it does seem to be a very good buy.
The RS stuff also has 'draw slides' and other interesting stuff that people have used for making there own tables with. Having had a look at a table made with these I was a little unsure but having seen it work (making pcb boards and small balsa parts) it does work very well. We used a vernier and found it good for 0.3mm (I kept rechecking because I couldn't belive it) the cutting size is around 300x300 mm with the z axis having 80 mm travel. The slight problem with it is the time factor for milling. A pcb around 250 x 200 takes a good hour and then sum however as my freind said IT GETS THE JOB DONE!
The total cost was around £120.00 which I thought was a very good buy, and I want one.
So many things to build, so that I can then get on and build other stuff!

Keep up the good work

Gus

xairflyer
03-18-2004, 05:48 AM
Slides I was thinking of using were Igus drylin N they look very good and well priced example no. ns-01-27-06.

The B&Q router is excellent value I am going to but another one as I want to leave one in the machine, I find the flexible drive and the angle grinder so useful for other things, I don't want to keep taking it in and out.

Gus_452000
03-18-2004, 06:31 AM
xairflyer,
just back from B&Q with the router (yet another router mt wife asked).
I cant find stainless tube of good quality and diameter so for x & y axis I'm going with the 20 mm linear bearing shafts from RS and will be using the alluminium alloy housed linear bearings, they come supplied with a linear bearing and although not cheap will I belive produce a very good quality table (if I can keep the rest working to tolerance that is).
My friend with the pcb (draw slide version) router is using a brushless electric motor as a router (they are made for model electric aeroplanes) it is very quiet and very, very powerful. Its called an 'outrigger' because the outside rotates with the prop or in this case a collet. He uses a brushless controller and speed is from nothing to very fast but the cost is ALOT. He was lucky he had one lying around.
Gus

glenfraser
03-18-2004, 06:38 AM
Can i ask a quick qestion to u as this is one which has been on my mind for a few days etc. WE put so much effort into the bearings either linear or like i am using 22mm skateboard bearings and the slides in my case from ondrives there ground steel bar. What the question is the we stick it on MDF for the bed etc. This cannot be truely flat. What is the error on this. Ive spent pounds etc even over a hundred on the metal bits. But then £9 on some mdf.

Whats your thoughts on this???

Glen

Gus_452000
03-18-2004, 06:55 AM
Glen,
I know what you are saying, I and everybody else must have thought the same. I am welding up a table which will also be a stand for the machine and it wll have supports underneath every 8" as long as I try and make everyyhing true then thats all you can do. MDF properbly isn't the best thing to make it from and we should be using aluminium or steel but as it was explained to me, when you have built this machine and get it working use it to make replacement parts from aluminium or steel. Or it it aint broke don't fix it. Both arguments are very valid.
I'm using MDF because others have tried it and they have had very good results but I will when finished try and make it better.
Cranky always says KISS and he is proberbly right.
Gus

glenfraser
03-18-2004, 07:40 AM
yeah thats what i thought. Mdf o.k for pcb drilling but not so hot when milling metal or wood where the deepth has to be spot on.
Its all down to the length of what you are milling i suspect.

Glen

Gus_452000
03-18-2004, 07:50 AM
Glen,
my mate has just pointed out to me a simple way of making sure the beds is level. When you finished your router and its working have the machine mill the bed from 'home' to the furthest point away. With luck you will remove very little but if you do then you have removed the high points, if you remove 0.05mm all the way from 'home' to end then its flat! It might need doing every now and again.
Back to simple draw slides for a moment Milford Instruments Ltd do a 3 axis machine that uses them and its cutting area is X axis 185mm, Y axis 185mm and Z axis 160mm they quote a resolution of 0.1mm!
You can down load a manual off their website for this machine, check out www.milinst.com.
Gus

glenfraser
03-18-2004, 08:41 AM
That makes sens... Mill itself...

Yeah the millford one is the one i first looked at but it didnt do A4 boards. In the end i went for kellyware software and the slides from ondrives have just turned up. Thought about going the draw slide way but thought s*d it and brought the rod. Got the stepper drivers from Quazar electronics and built those this morning. £9.95 a kit so £30 for the 3 motors. Will need to add some resistors but who cares.
Stepper motors i was given this end but might not be upto it but ill have to wait and see. Drill is a dremel £60 from argos but will look at b&q at the router and also going to get the mdf from them.


Glen

Gus_452000
03-18-2004, 09:03 AM
Glen,
interested by the kellyware software, where, who, how much?
Gus

glenfraser
03-18-2004, 10:30 AM
http://www.kellyware.com/

About £50 ish. U can try it for free just download and if u buy he sends u a code.

Glen

Gus_452000
03-18-2004, 01:23 PM
Cheers Glen will check it out!
Gus

xairflyer
03-18-2004, 03:28 PM
It depends also on the thickness of the mdf 1" actually 26mm is as ridged as hell, my base is 36 x 34 I have made a steel frame out of 2 x1 box.
If 1" mdf is well braced (end rails etc) and painted it will be ok.

RS do various different types of shafts the numbers I posted a couple of messages ago are the best value but still excellent quality.

glenfraser
03-18-2004, 03:44 PM
26mm good call i have 18mm but will try to track some down.#
Missed out on the B&Q router deal southend have only ones at £54 ish.

Glen

Gus_452000
03-19-2004, 04:49 AM
Hi all,
downloaded the kellyware and am playing about with it, first impressions looks good.

xairflyer, I,m using the 20mm steel shafts form RS my tables cutting area will be 12" x 24" with a Z axis of around 4-6". Its design is a bit of yours and a bit of balsamans. What driver card will you be using for the steppers?

As for the next table (I know get this one finished first) it will be for doing PCB and have thought that I would design it with 'cardboard' so that all parts interlock and then transfer these shapes to the cad package and mill it from 2mm aluminium (cutting size will be around A4 size). Had a thought of using brass or copper and soldering the thing together but if done properly the aluminium could be simply epoxied together on the thin stuff and tapped and screwed on the thicker stuff.
This router would be a lot smaller but (hopefully) more acurate than the bigger one, hopefully.

Thoughts?

Gus

xairflyer
03-19-2004, 02:22 PM
I'm using the k179 kit from quasar electronics for now.

If I was going to buy a commercial unit I would get the Xyolex.

Glen try B&Q online www.diy.com you can by it there as well

glenfraser
03-19-2004, 04:19 PM
Cant seem to find it on there. Can you if so whats it under...

Glen

xairflyer
03-19-2004, 09:08 PM
It is not there anymore, just comes up this product is not available, try another B&Q store, bound to be one with it in stock.

glenfraser
03-20-2004, 02:00 PM
I searched most of today loads of stoes etc but none to be had. Not to worry back to the dremel...

Glen

kong
03-20-2004, 02:54 PM
What about the little Trend router?
http://www.axminster.co.uk/default.asp?part=TRENDT3EK
I think it would serve better than a dremel, but the collet may be a little large?

glenfraser
03-20-2004, 04:19 PM
Not bad, and a good make. How do they do this stuff for this money... And post free...


Glen:)

xairflyer
03-20-2004, 05:17 PM
that's an ideal router, 1/4 collet is what you want as ypu can use a whole range of milling machine catters and it fits all the standard router bits too.

Gus_452000
03-23-2004, 02:33 PM
XAIRFLYER,
What software are you going to use?
I don't know if you have seen it but there is some free stuff from Emachine which you download and design your 'whatever' on then send it back to them and they produce the goods! What we need is a cad package as good as theres that then converts it to G code and then controllers the steppers. I would like to think that someone will say 'hay have you not seen this' and point us in the right direction but I doubt it.

Any thoughts

Gus

kong
03-23-2004, 04:40 PM
Gus, there's plenty of cheap stuff around. You can use Ace converter to generate 2d g-code, or if you buy the Mach2 cnc controller, it will import your dxf or jpg files to generate g-code for you. It also includes a toolpath verifyer. Well worth $150US. As for cad, I use turbocad. You can get it cheap on ebay, but I got mine from Australia - http://www.narellansoftware.com/ but it worked out that the shipping was more than the software! There is also a freee version which will do 2d only somewhere on the net.

Gus_452000
03-25-2004, 02:48 AM
xairflyer,
hows that table coming on?
I'm stuck in to having to move house (hopefully bigger workshops no neighbours, she in doors wants more bedrooms!)
How about a few more pics.

Gus

glenfraser
03-25-2004, 03:19 AM
HI,Gus
Could do with some more room myself in southend on sea and i have people next door. Hope all goes well with your move.
Just about to start my build soon.

Glen

davesaudio
03-25-2004, 08:16 AM
southend on sea -cool - does that mean Gus is related to the "Prince of Prittlewell?"
http://www.southend.gov.uk/content.asp?content=3112

EDIT: yes sorry, should have said Glen not Gus
this all started cuz I was half asleep and had to google to
comprehend that "southend on sea" was a "place"
I'm gonna go have a nap now....
:confused:

glenfraser
03-25-2004, 10:09 AM
I dont think gus does live in southend but i do. i dont no were he lives..
Glen

yukonho
03-25-2004, 10:32 AM
A trial version of Mach 2 is available free. It can do something like a thousand lines of gcode, more than enough for most hobby things. I use it and it is absolutely fantastic!
co

Gus_452000
03-25-2004, 01:17 PM
Will give Mach 2 a test run, as it were.
I'm based in Yorkshire, Southend isn't that near where 'dads army' was based?
Has to be 'nation's best sitcom', got my vote.
Have been looking at houses all day, very boring but found one with 3 rooms in the celler and a double garage!
That will do for me.

Gus

glenfraser
03-25-2004, 01:49 PM
sounds nice. No dads army filmed in Norfolk about an hour and half from this end.
Germen: YOur name will also go in the book. What is it!
Manering: Dont tell him Pike

xairflyer
03-26-2004, 06:34 PM
I am in the middle of re assembly and setting up after painting, took a long time getting all painted the way I wanted it.

Will post some pics in the next couple of days.

I am going to use TurboCNC for now, also desk engrave for some simple starting to learn stuff.

Gus_452000
04-05-2004, 04:19 PM
xairflyer,
hows that table coming?
I'm living in a house full of cardboard box's (the wife is getting ready to move) and my workshop is full of rubbish that she should have thrown out years ago, so I am stuck in front of the pc and cant do anything.
You where finishing off the painting last I heard, is it finished, any pictures.
Keep going mate, you have come to far to leave it like this.
Finish this baby, and with luck you will be making parts for you own flyer!

Best wishes

Gus

xairflyer
04-05-2004, 09:00 PM
Nearly have it back together, I am busy trying to get my new aircraft finished so I am not getting as much time on the cnc as I would like.

I have a couple of parts I want to cut out of lexan for it so I would like to get it running fairly soon.

Below is a pic of how it is coming together to wet the appetite.

Gus_452000
04-06-2004, 09:41 AM
xairflyer,
That looks like the 'dogs whatsits' absolutley brilliant.
It really is coming together and looking great, the scateboard bearings are better than I thought they would but I will be using ground steel rods and bearings from RS supplies (because I have them already).
Where do you get your supply of white nylon from?
It really does look great, keep at it!

Gus

xairflyer
04-06-2004, 03:01 PM
I have a mate who works in a toolroom and he gets a bit for me now and then.

Radionics do it but not cheap, I recently bought some round nylon on ebay, nice and cheap.

Gus_452000
04-07-2004, 02:39 AM
many thanks for that xairflyer, the wife just asked me 'what does the dogs whatsits' mean and I then thought that I hope you know as well. Incase you don't it means the best thing since sliced bread (the saying is usually used by blue collar workers (like me) on the shop floor).
Anyhow very impressed with what you have done and am looking forward to seeing it start cutting with vengence.

Best wishes

Gus

Gus_452000
04-16-2004, 11:14 AM
xairflyer,
whats happening, any more done to your table?
They say moving house is the most stressfull thing you can do and they are right, I am sick of estate agents, seeing houses, and people telling me that subsidence doen't matter but above all I am completely lost without my workshop. I had hoped we would have moved by now, but there are a lot of 'muppets' out there who pull out of chains without warning!
Lets see some more pictures and updates I am going out of my 'shell like' up here!

Best regards


Gus

xairflyer
04-16-2004, 08:07 PM
I'm a bit frustrated at the moment as I can't get working at it.

I am in Taunton somerset at present, finishing off customers aeroplanes.
Back in a couple of days but then have our big trade show a week later and will be flat out getting ready for that !!!:(

Might get a day a couple of evenings next week to connect it up to the PC.

Cold Fusion
04-16-2004, 10:07 PM
Bu sure to let me know how the Lexan cuts and what feeds you use. I am going to be mass producing parts in Lexan...

Gus_452000
04-18-2004, 06:10 AM
xairflyer,
don't drink to much of that 'scrumpy' or you will be sick as a pig for a week, I know my wife has an relative down there. Learn from my mistakes, she still brings it up when we have an arguement!
Being a monk sometimes sounds quite good.

Best regards

Gus

davesaudio
04-25-2004, 12:02 PM
I have been pondering this a while,
IMHO-I'm finding the roll-tap as a bit counter-intuitive when applied to MDF.
If it's purpose is to displace material- that is perfectly logical for
sheet metals in a flanged / flared hole.
To displace MDF suggests breaking the glue-particle bonds.

If it makes an undersized hole then I can understand how the
screw is grabbed in the threads and shank but otherwise I don't get it?.

:confused:

xairflyer
04-25-2004, 02:05 PM
The simple difference is when you tap a hole with a normal tap you remove material to cut the thread, the roll tap takes what it removes from the bottom of first thread and pushes it into the peak of the next, so strengthening the thread form.

davesaudio
04-25-2004, 04:44 PM
Still having trouble applying this to MDF, can't see how it's that plastic? Anyways, whatever its doing in that hole - its make a good thread so I'll shutup.

ger21
04-25-2004, 07:35 PM
MDF is really pretty soft under the surface layer, that's probably why it works well.

xairflyer
06-03-2004, 06:44 AM
Hope to have this machine up and running shortly (at last). Unfortunatly I never got it finished before I had to begin work on my new aeroplane which needs to be finished before 10th June due to airworthiness requirements.

So the past three months nothing has been done to my machine bar the odd collection of tracking etc for the cables.

During building the plane I had to make a couple of parts from Lexan which I could have easily done on the CNC and was tempted to spend a week finishing it off, but had to resist and cut the bits out by hand.

Will come back shortly with the progress, just need to set up the rails and wire it all up again. Then the fun begins with the software.

Gus_452000
07-18-2004, 02:27 AM
xairflyer, how is that machine of yours coming on?
It has been a while since I was able to visit the thread and you had a plane to finish first, so the CNC had to go on the back buner. Have you got anymore done, all my stuff is in bits in the new garage along with a mountain of boxs that still have to be unpacked for the house. Still got the PC working and have been busy earning money so she who must be obeyed can spend it.
Any photos?
regards
Gus

xairflyer
07-24-2004, 02:42 PM
Hi Gus

Yes finally back working on it. I am setting up the rails at the moment, got all the motors fitted again and Just have to cut out a replaceable cutting table to fit onto the main one.

Next job will be connecting it to the PC - could be fun

JIMMY
08-07-2004, 05:37 PM
Here is my desigh so far. Ihave not added any rails because I don't know what kind I am getting yet.

bgriggs
08-17-2004, 05:58 PM
xairflyer,
My friend with the pcb (draw slide version) router is using a brushless electric motor as a router (they are made for model electric aeroplanes) it is very quiet and very, very powerful. Its called an 'outrigger' because the outside rotates with the prop or in this case a collet. He uses a brushless controller and speed is from nothing to very fast but the cost is ALOT. He was lucky he had one lying around.
Gus

Do you think you can get a picture of the brushless outrunner motor your friend is using? I am interested in the specifications. I have hand wound several motors like this and think it would be cool to make a custom spindle.


Bill

xairflyer
12-14-2004, 03:28 PM
I'm back at my machine again, had a very busy summer with a new aeroplane we are working on and I have found that even though flying (both models and full size) was once my hobby the full size side of things has now taken over my life !

So I have dusted down my CNC Machine (glad I got to the painting stage before I let it go for a while) and have now aquired a PC especially for it so I can get my motors wired up.

There has been probably loads happening since I last viewed the site (Aug) I expect there is some new software, so once I get things connected up I will be asking the questions !!!

Any of you guys who corresponded with me before have there machines working I would love to see how they turned out so let me know.

Seamus

xairflyer
12-19-2004, 06:49 AM
I have decided to order HobbyCNC's board (very well priced, I think it worked out about 80 euro delivered hard to beat that) and keep my single driver boards for manual testing etc.

I am trying to set up my rails and it takes a bit of time to get right, I think I will need to add some supports to prevent flexing especially on the Y axis. Dont know whether to go with a fixed piece of wood or some sort of adjustable screw.

Next stage will be getting the PC to move my steppers !!

berin
01-22-2005, 02:00 PM
why not both. fixed wood to a Point AND THEN a 2-3 peice screw setup to ensure there is no movment at the highest point of movment, being the center of the two rails making up the Y axis on your machine.
I'm thinking if you use two screws you can basicly do the same thing a 4 screw mounting block does. Just matching the two screws to be at the opposite of your bearings on your Y axis. That will remove all up down and foward and backword or twist if you will, flex generated by resistance of the cutting tool. Would also dampin vibrations generated by the cutter bit kicking when it hits something hard to cut.

xairflyer
01-22-2005, 02:27 PM
Cant put anything on the inside of the rails due to the Z axis, The z axis will keep the rails apart ok, just need to prevent widening of the rails and fore and aft movement.

Y axis is the weakest link, when I get it running I will change it to soild bar and use pacific bearings like the z axis.

berin
01-22-2005, 02:50 PM
I dont think you are following what I'm trying to say due to my wording. Ok, here is the deal. you have your Y axis travling on the INSIDE inbetween the two parallel rails. with bearings. Now the problem is the bottem rail can bow down a bit and the top rail can bow up a bit. either or and you get a lot of extra play in the Y axis due to this gap created. So what I'm saying is becuase your only covering one half of the rail using the bearings in a V shap. You should make like a HALF mounting chuck like you have your RAIL's alined with. do a half block looking like a V on the TOP rail and a v on the bottem rail. So all you have to do is tighten the screws till they make contact. Then add even tightening, to make sure its secure. This would be in the middle of the rail, and the Z is the transfer unit of tention. I could draw and post a PICTURE if you would like but its an EASY and sound way of making the Y axis 100% secure and stable.

xairflyer
01-22-2005, 10:13 PM
I understand now what your getting at, I will try it out.

xairflyer
02-12-2005, 08:01 PM
I am having problems with my z axis motor stalling. The motor is new and 127 ozins all I am ding is running the carriage up and down with no router attached.

I think it is my leadscrew (which is 10mm all thread) is tight in the nylon block, I am running it manualy with a driver board single phase mode and not by the PC so I was wondering would it be ok in 2 phase mode which will give it more torque.

xairflyer
02-12-2005, 08:40 PM
Just been reading MVaughn's log and I think I will remove my drive block on my Z axis a make sure it is running freely, and try stick it in the freezer to shrink it before re tapping.

xairflyer
02-13-2005, 07:24 PM
Took apart the Z axis again today, and my 18v cordless drill had a job turning the screw !! So I thought I'd better strip it and free it up.

The drive screw is 12mm x 1.75 pitch all thread not 10mm as previously posted, approx equivelent to 14 teeth per inch.

Made the tap from a piece of the all thread originally so I decide to run a proper 12mm tap down it. Done that then ran my homemade tap in it a few times and all was well.

Fitted a IGUS flange bearing to the turned down end of the drive screw and All nice and free now.

berin
02-14-2005, 09:53 AM
you may want to think about gearing, that motor is plenty strong enuff to lift your Z, HECK thats 20x more powerfull then the motor on my Z BUT I have my setup geared. 50/1 ratio aprox. Sure I loose some speed but at least I have 10lbs of lift with a 2" wide x1" tall motor 7.5* stepper. An other question I have is what are you running again for power to your stepper motor? remember you can run upto aprox 15-20x the ratted voltage on the motor so long as your using a chopper driver to keep the current in check. For your setup I'd reccomend at least 30v provided your motors are ratted for at least 2volts. voltage + proper current = fast powerful motor.
Also the 2 phase suggestion you had mentioned. If your motor is a 4,6, or 8 wire mtoor you can set it up as a bipolar 2 phase motor which will give just shy of 2x the tork. Highly reccomended provided your coil resistance is below 30ohms.

Also how did that mod that I had suggested to you work out for you, on removing the flex in the Y axis?

xairflyer
02-14-2005, 01:27 PM
I am just working on the Y axis again today, I have actually drilled into the middle of the bottom rail and fixed it to the gantry, so now there is no flex. I have it set to the X axis and now I am going to set the top rail to that.

Obviously I can't do the same to the top rail as I will have no adjustment, so I will use roughly what you suggested, only snag is I will have to make the adjusting blocks probably from alum, as there won't be sufficent clearance to allow much 'meat' between the tapped hole for the adjusting bolt and the edge if you know what I mean.

xairflyer
02-14-2005, 07:57 PM
Got the Y axis rails set to the X axis so everything is nice and square and perpendicular. Took me a while to figure out how to do it so I have done this out for my own benifit as well for reference in case I forget it again !!

Clamped a piece of aluminum channel (nice and streight) to the top of my table and set it square to the X axis rails/table edge.

All ready had the bottom Y axis rail level to the top of the table, so I then positioned my square (looks old - it is, but accurate) between the aluminium channel and the Bottom Y axis rail.
Brought the table forward so the square was just touching the rail then moved it across to the other side and set it the same.

Once I had the bottom rail set I, roughly set the top rail, then re fitted the Z axis in place.

I then used the square again to set the top rail flush with the bottom one on both sides and checked in the middle.

Spacing between the rails is set by the Z axis, once I felt it was right and all the bearings were turning on the full travel, I checked the measurements in between with a large vernier, and adjusted the rails to get them to match.
This process went back and forth until it was right.

Only thing left to do is finish the half chuck for the top rail to prevent any flexing.

xairflyer
02-21-2005, 07:30 PM
Added a support to the top rail of my Y axis as suggested by Berin.

Not much room as the Z axis comes very close, so I had to use a grub screw for the outer one (hard to see in picture) so there was sufficent clearance.

Mainly wanted it to prevent any upward or forward flexing and it seems to have stopped that. Will make a new one once I have the machine running, as I have a few extra holes in this one !

Everything is setup now so I am ready to connect to the PC.

I think I will play about with a few spare motors on the bench first to I see how everything works, I have as yet not really looked at any software or how to use it. I bought turbocnc so will try it out first.

Anyone got a file I can use to get me going, something simple just so I can get all the motors moving in a simple cut.

morrissp
02-22-2005, 12:01 PM
Just found this thread guys, great stuff. Keep the UK links coming as I havn't started building mine as the prices for motor's etc here are high compared to the US. But this thread has got me going again.

If you have a plan that can be built without milling machine's etc any chance of a copy/ link

Steve

kong
02-22-2005, 12:27 PM
xairflyer, just set up Turbocnc and use the jog buttons, or simple G00 moves . That will be plenty to get the motors moving.

xairflyer
02-22-2005, 01:58 PM
There is a set of plans available to down load on this site.

http://cnczone.com/modules.php?name=Downloads&file=viewfile&id=4

xairflyer
02-22-2005, 02:01 PM
Thanks Kong, going out to the workshop NOW to connect things up

MrBean
02-22-2005, 02:19 PM
Just found this thread guys, great stuff. Keep the UK links coming as I havn't started building mine as the prices for motor's etc here are high compared to the US. But this thread has got me going again.

If you have a plan that can be built without milling machine's etc any chance of a copy/ link

Steve


If you're looking for steppers in the UK, this site may be worth a look.

http://www.distel.co.uk/asps/all.asp?TR=53

Regards Terry.....

morrissp
02-23-2005, 09:23 AM
Thanks guys

Had a look at the distel site, would these be ok for a cnc machine to cut balsa/ ply etc.: 5.1V @ 1.3A 4PH 110-OZ 200 STEPPER MOTOR

Steve

berin
02-23-2005, 09:55 AM
Xairflyer, so tell me how did the that fix I had suggested work out? you made it exactly how I was thinking. I would reccomend you considering adding maybe 4 more to have 6 of those half arches between the top and bottem rails to mop up any more play that may rear its uggly head SHOULD you find that that is the case. But in any case if your looking for some good example files. there are a lot of them on the net or look me up and I can set you up with some good files to play with.

berin1 at hotmail dot com
I've made guinness logo, i've made a logo for the local chines food resturant (my best firends parents own it), I'm working on making stuff for a local bar ect.......
Also if your looking for ways to ensure squreness there are some tricks you can do. For example take some kind of wood pine maybe? and cut exactly equal in demention peices 4 of them. or just get precut stuff and make some squars out of them. Then put one squar in each farthest corner and clamp it down. Then put some kind of a routing bit on your rotory tool. next make a half depth cut into the wood at each corner. either dive or router in via a side. Do this for each of the 4 corners. Next un clamp them and mesure the depth from the bottem to the wood to the bottem of the cut. If its off then you know that side is to high or low.

MrBean
02-23-2005, 10:14 AM
Thanks guys

Had a look at the distel site, would these be ok for a cnc machine to cut balsa/ ply etc.: 5.1V @ 1.3A 4PH 110-OZ 200 STEPPER MOTOR

Steve


Those are the exact ones I bought. Been cutting MDF and some aluminium with my machine. I'm driving mine with Alans PICStep drivers at the minute (Bipolar half winding).

Regards Terry
www.terry-is.f2s.com

morrissp
02-23-2005, 12:53 PM
Those are the exact ones I bought. Been cutting MDF and some aluminium with my machine. I'm driving mine with Alans PICStep drivers at the minute (Bipolar half winding).

Regards Terry
www.terry-is.f2s.com

Thanks Terry, looks like I've started collecting parts :cheers:

Steve

xairflyer
02-23-2005, 01:22 PM
Xairflyer, so tell me how did the that fix I had suggested work out? you made it exactly how I was thinking. I would reccomend you considering adding maybe 4 more to have 6 of those half arches between the top and bottem rails to mop up any more play that may rear its uggly head SHOULD you find that that is the case.


Yes Berin they are working out fine. I will make up new ones probably form ally when I get things working.

Connected my hobbyCNC board to three spare steppers on the bench and eventually found out how to jog them about after I set things up in the configuration.

Had to do this twice as I lost it all once I came out of TCNC did'nt realise you had to save the file and then reload it every time you open the program.

I know nothing about G codes but eventually got the motors to run on there own with a sample file in the program.

Can't figure out how to jog to a position and start from there as any sample files I have returned it to the beginning again !!

When I press F8 and go into the Jog screen, I can get a axis to go to a point, but it won't let me zero it at that point ? going to have a look on the turbocnc forums to see what I can find out.

xairflyer
02-23-2005, 08:22 PM
Connected up to my machine tonight and finally got a gcode program to work that I could understand.
Figured out how to setup deskengrave and typed the word JOE, after a few attempts got the sizes right and cutting (drawing) speeds.

Going to put together a step by step "how to get going" file and post it on here, as I spent a lot of time myself the past couple of nights on what some would consider basic stuff, but not that simple when you have not done it before.

Stuck a pencil in the collet of my router and left the Z axis motor on the bench (did'nt want to break my pencil :-)

So below is a picture of the first thing my machine actually done on its own.
It works !!!

Might get brave tomorrow eve and wire up the Z axis and try a cut (after I make the actual cutting table) - first cut will have to be JOE again as that is all I can figure out at the moment !

joecnc2006
02-23-2005, 08:33 PM
Excelent, that will help others also.

berin
02-24-2005, 09:53 AM
when I get home I'll a good file for ya, but I'll worn ya early, this will require a FINE tip! either one that comes to a fine point? or just a fine ball tip. (in other words 1/8th dremel bits). I'll also scale the thing I'll send you up a bit. I'll also take it one step firther hee..hee..hee..! the file I'll send you I'll code it so it requires a cutter bit at the end of the processes and will cut the thing out. So you'll have to raise the work peice or set it on top of an other bock of level wood so as to not cut into your cnc working tray.


P.S. THIS ALSO MEANS YOUR FIRST TOOL SWAP, I'll explain IN the file live how to set the right depth on the fly using turbocnc. Becuase there is a PAUSE function which which works great. because I can also add comments into the gcode file which you can read on the fly ;).

JavaDog
02-24-2005, 11:22 AM
when I get home I'll a good file for ya..........

Is this something you will be willing to share? I'm sure it would be helpful to all of us! :banana:

Hobbiest
02-24-2005, 12:45 PM
I've made guinness logo, i've made a logo for the local chines food resturant (my best firends parents own it), I'm working on making stuff for a local bar ect.......
.
Mmmmm...Guinness...along with Bushmills, the necter of the gods.

Looking good Xairflyer! Glad to have you back, and working on your machine again!

xairflyer
02-24-2005, 01:53 PM
Not fair I will have to wait until tomorrow due to the time difference !

berin
02-25-2005, 12:05 PM
I gues I could share the file with the world but i wont be home till late tonight fri. due to the fact that I have to go hang out with my parents tonight :p .... Oh well got to be the good son. xairflyer will prob give an explosion of delight on this post after he runs the file I emailed him.
by the way I'm in the USA/eastern time zone

xairflyer
02-25-2005, 09:41 PM
I have some sort of snag with my measurements in turbocnc, 600 on the screen for the X axis is only 300 on the machine, also the Y is also half what the screen says (I am using mm).

ger21
02-26-2005, 01:21 AM
I have some sort of snag with my measurements in turbocnc, 600 on the screen for the X axis is only 300 on the machine, also the Y is also half what the screen says (I am using mm).

Cut your step size in half. Under scale in the motion parameters.

xairflyer
02-26-2005, 05:35 AM
Cut your step size in half. Under scale in the motion parameters.

Is this what is wrong or is it just a fix ?

kong
02-26-2005, 08:22 AM
Xairflyer, if you have microstepping on your drives, this could be the cause of the mis-calculation.

berin
02-26-2005, 08:43 AM
its only a miss calculation easy fix, I belive you have your setup straight connected no gearing, ok simple to do the math.
say your rod is 20 turns per inch, and your stepping motors are 100 steps per rotation on whole stepping. (tpr=turns per rotation/tpi=turns per inch) 100tprx20tpi=2000 steps per inch. ok now to turn that into a dec. which is what turbo runs on 1"/2000step 1 inch devided by your total steps per inch. yields .005 or five thousands per inch per step . Ok so if your half seping that would be .00025 25 thousands per inch per step.
Just remember the number of steps your motor takes per rotation * the number of turns the screw, lead screw what ever takes per inch is your total steps per inch. Then devide 1 inch which is what your mesuring by that large number to get your decemal. Thats on a direct drive though which you have. If you are using a geared system like I am there are just more numbers involved. And that is nothing more then counting the number of teeth to do a ratio.
so to cap off if your half stepping a 100 step per rotation motor then your going to end up with 200 steps, or 1/4 stepping you'll end up with 400 steps per rotation etc......

ger21
02-26-2005, 08:49 AM
Is this what is wrong or is it just a fix ?

Both :)

Tell us your lead screw tpi, and what microstep setting your HobbyCNC board is set at.

OK, I see in one of your posts that your screws are 1.75mm pitch. Under the motion parameters, highlight the scale line and hit "C" for calc.
Enter 200 for steps / rev, 1.75 for Pitch, NUmber of microsteps (8 if set to 1/8), and leave gear ratio at 1:1. You should see .00109375 for your settting.

berin
02-26-2005, 08:53 AM
xairflyer have you run the file? and what do ya think? To the rest of ya who wanted that file of mine here it is.

let me know what ya think!!!!!!!!!!!!!

LeeWay
02-26-2005, 09:49 AM
Brilliant! :) I can't run it yet, but would like to in a week or two, give or take a month or two. ;)

Nice job so far, Xairflyer. Interesting thread.

berin
02-26-2005, 11:16 AM
ger21, the settings in the controller make little difference. Its the controlling software which must know what the controller is doing PEIROD! Also pitches and all that also make little difference in the equastion. The only thing that matters is the number of turns of the leadscrew per inch, and the number of steps it takes to turn lead screw one turn. Then you * those numbers togeather and you have the numbers you need to know period for any controlling software. 1" is an easy unversal mesurment.
So if its a straight shaft driven or geared via gears or belts etc..... doesnt matter there are the only two numbers you need to know period! Number of steps by the stepping motor to turn the lead screw once and the number of turns of the lead screw to move one inch.
Just for an example if your motor is on a geared setup with a 50/1 gear ratio, and your lead screw is a 20tpi. and the motor is a 48step motor 1/4 stepping just to make it tricky ;). Remember if half or micro stepping multiply the denominator by the base number of whole steps of a stepping motor. So half stepping is 2xspr motor 1/4 stepping is 4xspr, same with 1/8-1/16 etc....(steps per rotation). Because its the number of times your increaseing the RES.-resolution of turns per rotation from the base whole stepping number of steps capable of the stepping motor.
well 4x48step=192 steps per turn, ok now 50/1 gear ratio 50 turns * 192 steps= 9600 spr OF the lead screw. So now if we know it takes 9600 steps of the motor to turn the lead screw once, and it takes 20 turns of the lead screw to equal 1".
20 leadscrew tpi*9600steper motor-spr of lead screw=192000. Now to make a decemal which turbocnc runs on to tell how many steps it takes to move X distance. X being 1" in the equasion that we are using. 1" / 192000spi=.000005208 520 hundred thousands per step per inch.
Any question's class? turbocnc runs on decemal, kcam runs on spi, so does mach1 I believe.

ger21
02-26-2005, 12:01 PM
The information I gave was entirely correct.


1" is an easy unversal mesurment.
Unless your using metric screws and cutting in mm.

The settings in TurboCNC make all the difference. I explained what he needed to enter in TurboCNC to make it work correctly. TurboCNC will do all the math for you.

I see your talking about his microstep setting. again, you can enter this in TurboCNC.

Also, he's using metric screws and mm, not inches. Metric screws are specified by pitch, NOT turns per inch. Again, TurboCNC has a place to enter this info. I explained the easy way to do it. With the 1.75mm pitch screw, and 1/8 microstepping, you need 8*200 steps per revolution, or 1600 steps to move 1.75mm. 1.75/1600 = .00109375 mm per step, which is what I also gave in the example above.

The method you describe above works fine for inch units.

The difference between TurboCNC and Mach2, is that in TurboCNC, you specify units/step, and in Mach2, you specify steps/unit.

ger21
02-26-2005, 12:45 PM
xairflyer have you run the file? and what do ya think? To the rest of ya who wanted that file of mine here it is.

let me know what ya think!!!!!!!!!!!!!

Berin, what did you create that with. It look like a raster to vector conversion. It looks like if it was cleaned up the file would be a fraction of the size it is now.

xairflyer
02-26-2005, 05:48 PM
No Berin I hav'nt ran it yet as I need to make sure my machine is actually setup properly first.

I think I know the problem now as I forgot about the half step which I have the hobbycnc board set at.
I have entered 200 for the steps instead of 400.

Why would you want 1/8 or 1/16 step would the movement not be extremly small ?

I am going to have a look at the setup now tonight and if OK I will try to run the file tomorrow.

ger21
02-26-2005, 06:19 PM
The reason to use 1/8 step is that the motors should run a lot smoother. That's the main purpose for microstrepping.

berin
02-26-2005, 07:02 PM
oh i'm sarry didnt catch the metric part first time. As to the file, no that was done free hand TOOK FOR EVER!!!! I have all of the micro jaged movments because when blown up to a certin size and routed it looks rather nice routed in clear plexy. Though that was my final beta not my final final. My true file peice is flipped over backwords so as to see the file from the back side of plexy. But the file was designed to be cut with a needle point milling bit. The file was created using dolphin cad.

and yes as ger21 said the micro stepping smooths out the motion of the motors. I'm sure in your bit of playing you've found that the entire machine vibrates considerably as the motors turn. The thing of it is is that the only time you get vibration is when your are at total magnetic stop point of one coil. if you run half step and run the machine slow, on every HALF step there isnt an impact sound of the magnet and shaft locking. Where as on the whole step which is the true stopping point there is an impact sound. The vibration can cause problems espcialy in find detail. And the smaller the micro step the higher the resolution is.

JavaDog
02-27-2005, 09:10 AM
and yes as ger21 said the micro stepping smooths out the motion of the motors. I'm sure in your bit of playing you've found that the entire machine vibrates considerably as the motors turn. The thing of it is is that the only time you get vibration is when your are at total magnetic stop point of one coil. if you run half step and run the machine slow, on every HALF step there isnt an impact sound of the magnet and shaft locking. Where as on the whole step which is the true stopping point there is an impact sound. The vibration can cause problems espcialy in find detail. And the smaller the micro step the higher the resolution is.

But also the slower the machines goes, right? Just asking to satisfy my own curiosity...

ger21
02-27-2005, 01:00 PM
But also the slower the machines goes, right? Just asking to satisfy my own curiosity...

No. If your using 1/8 step microstepping, for example, the computer just sends 8 steps in the same amount of time it would normally send 1 step if using full steps.

The exception, which usually only applies to servos with higher encoder counts, is if your computer can't send steps fast enough, than your speed may be limited. Mach2 can output 45,000 steps/ second. DeskCNC 125,000. And Gecko announced that in a few months, they'll be releasing a pulse generator, which Mach2 will support, which can output I *think* 400,000 steps per second.

xairflyer
02-27-2005, 02:36 PM
In the instructions with the HobbyCNC board they mention that using 1/8 or 1/16th step require's a lot of computing power. Are they referring to the software or the actual pc hardware processor, memory etc.

ger21
02-27-2005, 03:12 PM
The only thing it requires is a faster pulse rate from your computer. With TurboCNC, faster computers CAN output faster pulse rates, up to a certain point. I really doubt you'd have a problem.

berin
02-27-2005, 04:05 PM
if you have less then a 486-25mhz using turbocnc and less then 16megs of memory NO WORRIE MY FRIEND NO WIRRIES!
Javadog the speed of the machines doesnt matter period, the only thing that matters is the material your working on. Because if its a precision machine think about it why would it be less accurate if the machine moves faster? (aside from flexing of the machine) unless your loosing steps the machine will always do correct movements. You just have to watch out for the way the material your cutting cuts. So say if you where routing metal like aluminum, you can only cut it so fast depending on the bit you have. If you have a cooling system you can cut faster but if you cut to fast you can also gum up the bit. Now if you are drawing plotter style using a machine, you really have no problems with speed. Heck the faster you go the sooner you finish :)

oneill222
02-28-2005, 01:46 PM
Looks great,

Have read through all of this thread with great interest!! Great looking machine and will hopefully be really solid and rigid. I would definatley pay to get hold of the plans for this... Please let me know if your interested in selling your plans !!!!!

Keep up the good work :banana:

xairflyer
03-02-2005, 08:14 AM
I am using 2 vexta 266 2A motors and 1 shianano Kenshi 2.4A motor and my 400W computor PSU is having none of it.
Although it is rated to 15A it is switching off when I try to run all three motors.
Total draw is 12.8A so it is pushing it, so I decide to search through my other steppers and find the one with the highest torque with less amps than the one on my X Axis table which is 2.4A for now anyway until I build a 24v PSU.

All my my motors apart from the Vexta 266's are second hand and I have not been able to get any specs on them.

So I have decided to test them myself.

I connected up each stepper in turn to one of my 6A single driver boards and made sure I had the resistors correct on each motor to match their ratings.
The motors were stopped so I could test a holding torque. :idea:

I then made up a lever from a piece of aluminium strip which I bolted to the stepper, and marked off segments for where I would apply a torque load.
I went with this method as I could grip the shaft in the vice, as It was easier than making up something that would'nt slip if I applied the torque load direct to the shaft and gripped the stepper in the vice.

As I really only wanted to do a comparison it would work just fine and the actual torque of the motor was not needed to be found, just the best one.

The amount of load applied depends on the length of your lever, I found that a little force gauge I had that went up to 350grms worked fine at 10-25cm depending on the motor. Just push or pull the lever at a measured spot until the motor slips.

As an example of some I tested my 2.4A 2.88v motor was 320g @ 20cm which equals 6400gf cm or approx 89 ozf ins

Another motor 1.2A 8v was 340g @ 25cm =8500gf cm or 118ozf ins
this was my best torque motor at the 12.3v of the PSU but being 8v was also the slowest.

I assume the lower voltage motors eg 3v turn faster at say 24v than a motor rated at 8v or is speed down to the motor itself ?

anyway for next time I will make a torque loading lever for the stepper shaft just to get better readings, but as I say for comparisons above works.
:cool:

berin
03-02-2005, 09:53 AM
if your PSU is cutting out the problem is more along the lines of the amount of resistance, and rate of draw.
put it this way, most COMPUTER PSU'S will trip if the resistance in the load is below 2-4ohms.
Also you mentioned that your 8v motor was very slow, something you should check on is the COIL resistanc of the motor. The rattings on the motors are the tolarences not the SET rattings. Stepping motors which have an ohms resistance between .5-10/15 ohms are always very fast and powerful, but the higher the resistance the more voltage the motor will require just to overcome its own resistance. If you want to try a test get a few 1-5ohms 10-20 watt dropping resisters (you know the kind that have a ceramic shell around them and are white and often squar-ish). And put each one in line between the motor driver and the computer PSU. you should find that the psu wont kick out on you any more. To be honist if you want a better setup, pick up 3 transfomers which output between 12-30v 2amps+. An other option which I took was to use multi laptop psu's which each output between 12-24v 2-4amps. works very nice and there is no sharing bandwith of the current problems :). Just have to watch out for the load requirments. happy cnc-ing

kong
03-02-2005, 10:08 AM
Not sure if you have already tried it, but a load on the 5v line of a PC PSU is always recommended. Around 1 Amp may help things, try a big resistor if you have a spare one, or plug in a whole bunch of 5v stuff!

xairflyer
03-02-2005, 01:51 PM
Not sure if you have already tried it, but a load on the 5v line of a PC PSU is always recommended. Around 1 Amp may help things, try a big resistor if you have a spare one, or plug in a whole bunch of 5v stuff!

I have two 10R 25W resistors in Parrallel inside the case of the PSU on the 5v
This should also give it the resistance Berin talks about.

I will try it again tonight, the board I am referring to when connected to the CNC is a HobbyCNC board so I can't use three seperate supply's.

The 8V motor is 1.2A 8 / 1.2 = 6.6 ohms when I measured the coils I got 6.4 ohms so it is not far of what it should be.

How can I test how fast I can run my motors in turbocnc do I just increase the frequency until they stall ?

joecnc2006
03-02-2005, 03:48 PM
can you take a pic of your power supply to make sure i did mine right? i have the same two resisters, and get 12.4 volts, have you measured yours?

thanks, Joe

ger21
03-02-2005, 06:09 PM
How can I test how fast I can run my motors in turbocnc do I just increase the frequency until they stall ?

Yes. Then people usually back it off 20% or more for a safety margin. Do the same thing with acceleration settings, and start speed. Do the start speed first. If you lower the start speed, you might be able to use higher acceleration settings. You need to play around with all the settings to find out what works best for your setup.

berin
03-02-2005, 06:12 PM
correction xairflyer yes you can still do the multi psu setup, the setup I have with my controller box and I'll load the image later tonight when I get back from the YMCA of my controller. has multi psu's wired in parallel, The key to this though when wireing switching PSU'S IN PARALLEL is thatyou use one BIG we$%@#$% diode in series of the +v output of the psu. then you combind the outputs togeather after the diode. The diodes stop the feed back which will disrupted or destroy the other switching psu's. Its a great setup to use, but you MUST use a rather large cap after all of the X number of switching psu's diodes. I reccomend 2x the Voltage and around 10,000uf-20,000uF per every 3 amps of output current. this is becuase if you over draw the psu will shut off auto protection. where as a transfomer only outputs what it outputs but its not going to just shut off on ya for no reason :). Well unless it over heats and has a total melt down on you!
The trick is to use the same psu's in parallel (make/model/specs). I prefer this method because its quick easy and you get a lot of current with out a big heavy transfomer. and you dont have to deal with the pains of a short circuit, because its built into the psu already :) your only requirement is to do the in line diodes in parallel, and throw a cap or two in.

xairflyer
03-02-2005, 09:01 PM
can you take a pic of your power supply to make sure i did mine right? i have the same two resisters, and get 12.4 volts, have you measured yours?

thanks, Joe
Here is a picture of my supply if it is any good to you, I fixed the 10R 15w resitors to the back of the case in line with the fan, resistors are wired in parrallel on the 5v.


Berin - will try what you say as I have another supply and a couple of BIG brute diodes.

Really want to build a 24v supply once I can get a transformer the right size.

ger21
03-02-2005, 09:52 PM
Really want to build a 24v supply once I can get a transformer the right size.

You do have the HobbyCNC chopper board, right? If so, then build a 35V supply, if the cost will be similar. You'll probably get close to 50% more top speed than with 24V.

xairflyer
03-03-2005, 07:32 AM
I can't seem to upload pictures anymore, in the bottom corner of my postings there is a icno whidh looks like a sheet of paper with a red X through it, I wonder have I been blocked sending attachments due to a virus or spyware problem coming from me I am unaware of ?

Might change the present email I use for this site to another

ger21
03-03-2005, 08:31 AM
The pictures might be too big, I think the max size is 800x800. I believe there is also a file size limit. You should see an error message telling you what the problem is.

berin
03-03-2005, 09:48 AM
I got busy last night didnt have time to upload the picture. I'll also upload a nice little schematic image design to give a better picture of the psu setup I'm talking about. Because it is very effective!
4hrs sleep every night this week due to just no NO free time. Ahh the life of a 20's year old person are always full of lack of rest!

xairflyer
03-03-2005, 11:08 AM
The pictures might be too big, I think the max size is 800x800. I believe there is also a file size limit. You should see an error message telling you what the problem is.

No I upload pictures all the time, when I press the manage attachments button nothing happens, I hav'nt even selected the picture to upload at that stage. :tired:

ger21
03-03-2005, 11:25 AM
Sounds like a problem with your browser. If your using IE, have you changed any security settings?

xairflyer
03-03-2005, 11:45 AM
I hav'nt changed anything, do you know what the icon is I am reffering to which is to the left of the edit icon I see on my posts ?

When I double click it this comes up :-


"xairflyer, you do not have permission to access this page. This could be due to one of several reasons:

Your user account may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation. "

joecnc2006
03-03-2005, 11:50 AM
the icon of a page with an x in it is for a mod of the site to delete the post i believe if they feel it inapropriate, i get that on my post's also.

is is more than likely has to be the size need to be below 800x800 or file byte size, less than 50k i think.

xairflyer
03-03-2005, 03:15 PM
No - Nothing happens when I press the manage Attachment button, I hav'nt even selected the file at that stage.

cncadmin
03-03-2005, 03:38 PM
No - Nothing happens when I press the manage Attachment button, I hav'nt even selected the file at that stage.

You have somthing blocking them, do you have a ad block program running? I just uploaded a pic using your account and had no problems.

xairflyer
03-03-2005, 04:15 PM
Never touched any of my security settings but whatever you done it is working again, thanks anyway.

Uploaded the psu pic Joe wanted in the original post (No. 184).

Anybody been using CAD 2 CAM ? been playing with it today, don't know how to get the gcode file it produces to run in tcnc4 but it is good for showing you the toolpaths.

xairflyer
03-03-2005, 09:34 PM
Decided to get some motor to leadscrew couplings instead of using plastic pipe.

Got two different types to try, the oldham coupling and the jaw coupling. (red star)

The ones I went for were 19mm in dia, got the clamp version for the leadscrew and the set screw type for the motor. The star - Jaw type looks really good but I prefer the oldham type as the centre disk can slide sideways to allow for slight miss-alignments (should see that in the last picture as I off set it for the photo).
Should also provide another backup if the machine goes crazy ! as they will shear under a limit load.

WP1
03-04-2005, 10:25 AM
The Oldham type will *not* shear under a load as the metal drive sections overlap. The "jaw" type will have the spider under shear load, but the Oldham type has the spider under compression only.

Pete C.

xairflyer
03-04-2005, 11:25 AM
The Oldham type will *not* shear under a load as the metal drive sections overlap. The "jaw" type will have the spider under shear load, but the Oldham type has the spider under compression only.

Pete C.

I must have a different style to what you are reffering to as these ones don't overlap.
Taken from the spec sheet about the torque disk "Under servere overload it will break cleanly acting as a mechanical fuse" the ones I have are rated for 10.5Nm (1480 ozins).

WP1
03-04-2005, 11:35 AM
I think we have the types reversed. The one in your picture with the orange/red spider is they type that I'm used to seeing as the Oldham/Lovejoy type of coupling. I've not seen the other style before.

Pete C.

LeeWay
03-04-2005, 12:10 PM
If you look at page catalog page 1041 at Mcmaster Carr, you will see that they don't mntion a normal spider coupling as being a fuse type. They do show a wrap around spider coupling thatacts like a fuse. The normal spider type coupling has the two cogs on each side. These two cogs offset each other and would still be in contact witheach other if the rubber was missing. It would still drive, just not well. Mucho backlash and destroy the couplings themselves eventually. If the cogs sheared off, it would mean they were cheap rather than a fuse. ;)
The other type you show is a slotted disc or Oldham coupling. They show these on the next page and these are indeed a fuse type coupling. :)

ger21
03-04-2005, 12:23 PM
I think we have the types reversed. The one in your picture with the orange/red spider is they type that I'm used to seeing as the Oldham/Lovejoy type of coupling. I've not seen the other style before.

Pete C.

For clarification:
The spider is Lovejoy, the slotted disc is Oldham.

xairflyer
03-06-2005, 06:58 PM
For some reason my machine is now doing a mirror image of the part, i.e the JOE i drew before now comes out EOJ but with the letters reversed ! anyone know what I have done wrong. (Hobbycnc board and turbocnc4)

ger21
03-06-2005, 07:12 PM
In Configeure>Axis, change the direction pin from + is high to + is lo, or the other way around. This would be for the axis going backwards only.

xairflyer
03-07-2005, 07:05 PM
Changed the setting in the configuration for the X axis and JOE is coming out the right way again.
Realised that I had changed the stepper motor on this axis since the first JOE was drawn and it must be going in the opposite direction.

Now that is sorted how do I get X to move in + numbers, as now since changing the setting in turbocnc, if I start X0 Y0 in the bottom left hand corner and my gcode has a line X10 it will be off the table so to speak as only -numbers will move into the table for that axis.

If I changed the motors wires instead of changing the settings in turbocnc would that cure it? or is it the same thing?

ger21
03-07-2005, 10:36 PM
Same thing. Is your X-axis the moving table? If so, your X0 Y0 ( @ lower left) should be with the table all the way to the right, and the Y-axis closest to you. +Y should move away from you, and +X should move the table to the left.

xairflyer
03-08-2005, 07:52 AM
Gerry I think I have been looking at this all wrong and from the wrong angle.

Yes what you say makes sense, I having been looking at the table from what I would call the front - facing the gantry, where I should have been looking at this from the side, which is obvious now I think on it, with the Y moving away from me and the X to the left.

The plan is to install the machine when finished with it facing out as shown in the picture, access to the right hand side would be limited and where I would intend to base the PC. So looking at it now I would be much better off changing the gantry to be X (640mm / 25ins travel) and the Table to be Y (300mm / 12ins travel).

And look at the table as you would a sheet of paper or screen on Autocad, does this make sense ?

kong
03-08-2005, 10:33 AM
Lol, we all look differently at this, you should use the method that suits you best. Personally I look at my machine from the side, and have your y-axis as my x-axis!

ger21
03-08-2005, 11:28 AM
And look at the table as you would a sheet of paper or screen on Autocad, does this make sense ?

That's what I would do. But, Like Kong says, make sure it works for the way YOU work.

berin
03-08-2005, 11:58 AM
an other way to look at it is, do you want to work in portrait or landscape? dependong on the design of the cnc table on the machine that you or any one has built.
My opinnion to you to save you from the most about of (PAIN) is to make the closed lower left corner your xy zero. That way when your working on projects any thing that you build on a screen in over head view will be in the same orientation when milled. An other suggestion I'd make is give your self between 1/4 and 1/2 " of extra space at all edges. That way if you want to add a numbering system I.E. WITH a pen or fine point miling bit, you can place them ON the machines working table. It comes in reaslly handy to have the machine draw up a grid for you on the table its self so you know where you are as far as alinment of work peices to be milled! TRUST ME.

xairflyer
03-08-2005, 01:14 PM
Thanks guys I had thought a lot of this was set in stone, then seen other machines with their table as the Y and gantrys as the X so started scratching the old head a bit !

I think it will work well in landscape form with the front lower left as my XY 0:0 as berin says, that way it looks right to me.

My table is 18" x 27" which is bigger than the working/cutting area 12" x 25" I made it like that so it gave plenty of cover to the bearings underneath to help keep them clean. So I have plenty of room to add a scale on the sides.

xairflyer
03-09-2005, 07:09 AM
Re set everything up and made a pen holder for the front of my router clamp, as I can see myself using it for some A3 size drawings as well. Although I think I will need to make something slightly spring loaded to keep even pressure on paper.

Loaded up berins file and was surprised how fine it could work, you need to have the Z lifting up more out of the way in rapids when using an ink pen as the paper would lift slightly and and ink hair traced the line of movement, still worked ok even though a bit smudgy, trying to get a small enough cutter to try on a piece of polycarbonate.

Hobbiest
03-09-2005, 01:01 PM
The machine looks awesome! Good job mate! And as for that Guinness...I've got a few in the fridge right now...oh yeah, you are all the way accross that big lake from me. Damn!!

santiniuk
03-09-2005, 02:39 PM
Great idea on the pen holder built into the clamp.

I hope you don't mind but I will copy that :)

Great looking machine.

xairflyer
03-09-2005, 03:06 PM
Great idea on the pen holder built into the clamp.

I hope you don't mind but I will copy that :)

Great looking machine.

Going to make a modified version now I have used it, you need to support the pen most of its length and/or clamp it closer to the tip to prevent flexing.
Also ideally a spring loaded design to keep slight pressure on the paper to prevent missing bits.

What I have started making is a aluminium tube (ID slide fit for the pen), which will have a screw on cap and a light spring under the cap, obviously something to stop the pen dropping out as well.

Need to keep the movement in spring small, otherwise you will have to lift the Z to far each time when moving.

Going to source some nice drawing pens with different colours and tip sizes but same dia barrels before I finalise the sizes.

Not really what the machine was built for but I could do with also being able to put drawings on bigger sheets than my normal A4 printer.

strat
03-09-2005, 04:08 PM
the pen holder looks good one prob i had (i tried something like that is the offset from the center (where my tool really rides ) so what i did i took a shaft from my dremal that screws into a buffer pad and remember the old pencils from school where you pulled the lead out and put in the top and it would push another out ?????? i screwed it on the shaft woks fine as long as your setting are ok just a fast cheap get around

10bulls
03-10-2005, 06:36 AM
...Not really what the machine was built for but I could do with also being able to put drawings on bigger sheets than my normal A4 printer.
I see there's an HPGL to GCODE converter around. I wonder if someone has wrapped this into a printer driver. Or even better, a printer driver interface direct into something like Mach2.

berin
03-10-2005, 10:03 AM
The machine looks awesome! Good job mate! And as for that Guinness...I've got a few in the fridge right now...oh yeah, you are all the way accross that big lake from me. Damn!!
Of my file? The one regret I have on that file is I never finished the A its still hollow, i gues I'll fix it some time shortly.
Xflyer I see you tryed my file finaly. You must have been over joyed and excited to watch as the image self generated its self. I do have one question for you though? did youever open the file in a graphic editor? or did you just run it to see what it came out with?

xairflyer
03-10-2005, 12:36 PM
Berin i open it first with quikstep, and was able to see what was going to happen, until I got these setups right I had know idea where it was going to start drawing/cutting from, some other gcodes I entered were heading off the table, as they had minus figures as well so they were obviously designed to sart in the middle of a table.
Got a small engraving type cutter today so I am going to try your logo on a piece of lexan tonight.

xairflyer
03-10-2005, 07:30 PM
Well finally done my first cut or really only an engrave on a piece of lexan with berins Guinness logo. :wee:

Came out great my cutter would have still have been a bit big for the signiture at the bottom but still made a nice job in the lexan.

Actually it is much better from behind, as it looks silver. I think I will be doing a mirror image for my next attempt.

Want now to scribe a circle around it and cut it out so I can fix it to my machine as the first thing it made ! :cheers:

berin
03-11-2005, 09:49 AM
If i feel upto it I'll create a TRUE mirror IMAGE of the file and fix the A in the file tonight and repost it.
And xairflyer I was going to mention but you already stole my thounder yes on plexy it always looks nicer on the back side. come out great if you use a very fine point milling bit. Also you have to be carful of your spindle speed or the plastic will melt. An easy fix for this is to put the work peice under water. And in some kind of an enclosure so that the water doesnt get wicked by the spindle bit and spray all over the place! Using the water trick ALSO makes it so you can increase the RPM of the spindle which makse a nicer look povide there is NO wobble in the bit. FOOD FOR THOUGHT.

The Wizard
03-11-2005, 05:52 PM
Well finally done my first cut or really only an engrave on a piece of lexan with berins Guinness logo. :wee:

Came out great my cutter would have still have been a bit big for the signiture at the bottom but still made a nice job in the lexan.

Actually it is much better from behind, as it looks silver. I think I will be doing a mirror image for my next attempt.

Want now to scribe a circle around it and cut it out so I can fix it to my machine as the first thing it made ! :cheers:

Nice! :cheers:

Have you tried 'edge lighting' it yet? As a quick test you can place two pieces of card over a flashlight so that the gap between the cards is the same width as the plexiglas/lexan. Turn the flashlight on and only the engraving will be illuminated. It can look quite striking with the right image.

I want to try doing some edge lit stuff once I finally get my machine finished (getting very close now).

Larry

berin
03-11-2005, 09:24 PM
I do that stuff all the time, I have a small business doing that stuff to be honist

xairflyer
03-14-2005, 07:42 AM
Having some problems with my home switches/software.

I am using turbocnc4 and I have placed a post on the turbocnc group but have failed to come uo with a solution.

First my home speed is about 1" a week, I have changed the speed in the config screen but makes no differece. :mad:

Second when my X axis hits the home switch (after it gets there on friday) the machine stops but the display still shows in motion and when I hit esc it shows 25400mm.

My Y axis is OK, I think the problem has got to do with the port settings because the X home pin (11) is inverted from the others when I look at it by pressing Alt F2.

Any ideas?? :tired:

10bulls
03-14-2005, 08:11 AM
Having some problems with my home switches/software...

Pin 11 (Busy) is indeed a hardware inverted pin, which means to get a logic high you'd need to ground the input. I'd also pull it high to 5V with a resistor of say 4k7. Have you tried measuring the voltage at pin 11? Do you see a nice 5V to 0V drop when the switch is activated?
Is it possible to try pin 12 or 13, which are not hardware inverted?
Good Luck.

xairflyer
03-14-2005, 10:16 AM
The pins are already pulled high with a 10k resistor on the hobbycnc board can the pin be set like 12,13,15 ? Maybe I will just try and move the X axis hime to pin 15.

10bulls
03-14-2005, 11:20 AM
The pins are already pulled high with a 10k...
Pins 10, 12, 13, 15 should all behave the same and are not inverted. If you can measure good voltages at pin 11 other possibilities are noise or you've blown pin 11.
Strangely enough, I have only ever blown one pin on a parallel port before, when building a PIC programmer. Just checked my notes and that was pin 11 as well! Maybe the inverter on this pin makes it a bit more delicate. If pin 11 is floating or blown it would explain the continuous 'moving' signal...and probably the slow speeds as it is constantly getting a 'stop-go' signal from noise.

xairflyer
03-14-2005, 04:52 PM
Don't know why pin 11 is inverted from the rest or why you can't change it, anyway problem solved made pin 15 my X home and chucked pin 11 over the hedge!

Still can't get my home speed any faster than start on Monday arrive Friday !

Going to have a go at Kcam, spending more time messing about with setting up the machine than using it, bit like computors in general !

Want to get a bit more engraving done.

ger21
03-14-2005, 08:28 PM
Under Configure > General Config... On the right side, Home Rate.

xairflyer
03-14-2005, 09:32 PM
Dos'nt work Ger, first thing I tried, this turbocnc seems to still have a lot of holes.

ger21
03-14-2005, 09:37 PM
try downloading the new version from http://www.dakeng.com

berin
03-15-2005, 09:44 AM
I can agree with that and then some, turbo has a LOT of bugs in it and I mean A LOT!!!!!! I have a GOOD mental list of things that are worng but to give you an example. say your off setting the machine to have Zero be somewhere else on the board. comes in handy at time. when you SET the new xy point to zero, you must quit turbo totaly and come back into the program, open your gcode file and continu. If you dont the new zero set point will be ignored and the oignal zero point will be used regardless of where it is.
as to the homming problem i know the feeling, there are a lot of small wierd bugs in the program which just dont make any sence to me. Like for example in my systems setup if I home any axis other then the X axis they all home fine. But if I home my X I have to hit HOME then hit escape key, then hit continu and it will home just fine?????????? makes a lot of (non)SENCE

ger21
03-15-2005, 10:09 AM
Any bugs should be reported on the Yahoo list, as none of the developers visit here very often (if at all). Then they might have a chance of being fixed.

xairflyer
03-20-2005, 02:14 PM
Anybody know of any good programs to convert gif's or jpegs to gcode?
Been trying out deskart but no having much success.


Latest cut in lexan little deeper than before used a 3mm end mill

Ninjak2k
03-23-2005, 01:29 AM
xairflyer, first, thanks for the build thread! System looks awesome.

I was hoping you could tell me what's your system for getting the material positioned properly, getting the router in the right place, etc. Does the position of the piece in the CAD program's grid become the position the machine will cut at? How do you accurately position the Z axis for the cutting?

Having read hundreds (thousands?) of post on construction and software in the past few days, I'm trying to integrate the two together and see how a design goes from CAD to done. Not the software progression (CAD->CAM/GGode->controller), but from design to how the router bit is positioned in the right place.

Hope those rambling thoughts/questions make sense. End of a long day and lots of reading.

~Dan

xairflyer
03-23-2005, 08:39 PM
Ninjak
You have asked what would appear to many a simple question that should be so obvious, but I have found that it is not. (well not to a first time cnc machine builder/programer).

I scratched my head about this as well when I tried to do my first cut and found that the answer to the question was not that easily found, so I am putting together a bit of text, that will be a "how to setup your machine and make a first cut" sort of thing, as I spent ages myself trying to figure out software settings etc before I could actually connect to my steppers and hit the run command. I will post it on here when I get it done.

Anyway back to your question, basicily anything you draw in cad and convert will be cut it that position, as regard to X, Y so you want to draw things around the X 0.0 & Y 0.0 positions in your cad program.
Now I think you may also in some cad/gcode conversion programs be able to specify the start position e.g. X10, Y10 etc.

As far as positioning the work on the table is concerned, you can zero the software anywhere so you can clamp down your piece and JOG (move) your router to where you want to start cutting and zero the relivent axis.
The problems I first had which seem again simple now (everything is once you know) was which way was the positive + numbers (which way the axis is going to move when you start cutting.)

I have also found now, what I was originally calling the X axis (moving table) has now became my Y axis as it suits better for the way I look at my machine and what I call the front and bottom left corner of my drawing (cutting) sheet (X0 Y0).

Generally you jog down your Z axis until your cutter touches the top of the material to be cut/engraved and you zero at this point. So to make a cut 1/4" deep you will have in your gcode a minus amount eg Z-.250.

Plus numbers will lift the Z axis clear of the piece for rapid movements etc.

I used a pen with the Z axis disconnected for my first movements just to see and understand how things worked.

LeeWay
03-23-2005, 10:47 PM
Just the little text in your reply has already enlightened me somewhat. Thanks for posting that. :)

berin
03-25-2005, 09:56 AM
your post is good but you left out some important info on the Z which can make a lot of people make an incorrect asumption about the Z. The Z is really the HARDEST axis to understand. and in all reality Z0 should be the bit JUST touching the work area with out material being cut. just the fixed or moving tray of the machine. so say if you where to use a 1" thick peice of wood. you can tell the Gcode to raise the work bit 1" and it will clear it. using negatives can confuse you and or even cuase you to make mis placed parts. The way xairflyer described it, the TOP of the work surface is 0. but the problem with that is that your then working with negative numbers. So you also ALWAYS have to repossion your hight on the Z. and when I say reposision I mean manualy seting a NEW zero point. Now if you know where the true zero is you can USE the machine its self to mesure the hight of the material. and then using the Gcode editor of your choice raise or lower the hight of the Gcode code to the corect posision. That is a one time processes vers readjusting every time you make a new tool path. Now on the other hand that method which xairflyer talked about works GREAT if you have differing material hight, like say if you where etching a face into a walking stick which use to be the root/stem of some small tree. Welll then that comes in REAL HANDY for on the FLY. but dont forget where your Zero point is. TRUE ME i FOGET ALL THE FREEKING TIME!

ger21
03-25-2005, 10:59 AM
I think the majority of people here set there Z=0 to the top of the PART. I think you're in the minority, Berin. What you call a one time process only works if all your parts are the same thickness. If there not, you have to edit all the g-code, vs setting the machine 0 to the top of the part. I prefer Z=0 to be the top of the part. Then you can run the same code on any thickness part.

joecnc2006
03-25-2005, 11:39 AM
I also start z=0.00 at the top of stock, but most programs will let you set the stock either at the top or bottom.

berin
03-25-2005, 04:34 PM
re-read the post I talked about BOTH methods and the points behind them.

xairflyer
03-25-2005, 05:34 PM
Berin The Z was the most confusing for me to understand, I like the idea of keeping the table top 0 at all all times as it saves any re-setting of the axis only snag is most of the gcodes seem to use -Z for depth, but I supose once you know what your doing you will always write the codes to suit what you say. I can really see this as being the best method if you tend to cut the same size material most of the time.

I do feel from a novice point of view zero'ing on the top of the piece to be machined is more streight forward and easier to understand espeially at the beginning when trying different materials and sizes.

xairflyer
03-25-2005, 06:23 PM
Working on upgrading my machine now I have it working, apart from building a 24v PSU, I am going to change the leadscrews from 8mm to 12mm Stainless all thread, apart from better speed I have found the 8mm does tend to whip a bit and the 12mm is much more rigid.

Turned down the end of the 12mm all thread to 8mm for my motor coupling and also the other end for my new flanged bearings I am going to fit on each side of the gantry ends.

Re threaded the end 8mm so I can lock the leadscrew with spacers against the bearing for my anti end float (thrust bearing).

Having a turned surface to run on the inside of the bearings stops that horrible sound you get from the thread running in the bearing.

Until I got the flanged bearings I was just using to washers screwed to the side to hold the bearing in place see picture, crude but works.

Ninjak2k
03-25-2005, 08:26 PM
Just a follow up on the "roll tap" mentioned earlier in this thread. I found several products call "thread forming taps" that sound just like what xairflyer described in terms of how they form the threads. The description stated that the threads are work hardened by the tap and that the material isn't chipped out. Here's one I found: thread forming tap (http://www.use-enco.com/CGI/INSRIT?PMAKA=313-1510&PMPXNO=2615630&PARTPG=INLMK32).

I was studying your process of getting your drive threads lined up with your base mentioned in post 15 (http://www.cnczone.com/forums/showpost.php?p=19121&postcount=15). Where you happy with how that turned out? Seems like a great way to do it to me. Otherwise, you'd have to be pretty darn accurate in your leadscrew nut placement in your base, right?

~Dan

xairflyer
03-25-2005, 09:27 PM
Yes that tap looks like the same thing, they are really designed to add a thread where the material is thin, generally in extrusions, so they remove as little material as possible. Great for MDF.

Procedure is drill slightly smaller than normal drill size e.g. tapping drill for 6mm is 5.2 I drilled the holes 5mm. Tap the hole, (I found a cordless drill great for speeding up the job) run thin modellers cyno (super glue) down the threads, leave to dry (longer the better) re tap again.
You will probably find that the tap gets clogged up after the second tap because of the glue, that is why better to leave the second tap as long as you can.

Yes the method I used worked well, and I wil be putting it to the test again as I am about to change the X,Y axis leadscrews as mentioned above.
Pre drill the bolt holes in your drive nut, easy then to mark the holes on your axis.
I found a nice accurate way of doing this was to turn up a point on a piece of 6mm rod, so when I pushed it through the nut I got two nice marks for drilling the axis.

I probably need to go back through my posts and add bits like this so other guys might find it useful.

jimdowd
03-31-2005, 11:19 AM
I think i bought the wrong wood. I bought MDF Luan. This stuff splits everytime i try to tap the wood. The wood is also alot darker. Do i have the wrong stuff?

ViperTX
03-31-2005, 11:29 AM
jimdowd,

I suspect what you have is stuff that has an MDF core and a Luan (mahogany) veneer on the outer surface.

Yes, you have the wrong stuff....I suspect that you could use it you just have to drill through the veneer (which is what is splintering)....oops you said splits.....hmmmmm....wrong stuff.

jimdowd
03-31-2005, 11:50 AM
actually no there is no veneer. I bought it at Home Depot. It says MDF on one of the stickers i just found. But i remember seeing on one of the other stickers MMDF Laun. This stuff is dense but it splits every time i either screw it or try to reverse the tap.

ger21
03-31-2005, 12:07 PM
MDF splits very easily if you don't predrill it with the proper size hole.

xairflyer
03-31-2005, 12:51 PM
Not sure what you have, I have never seen the stuff I use split when tapped unless very close to the edge, even then with the correct pilot hole it is ok

berin
03-31-2005, 05:05 PM
I bet he has MDF and yes MDF will split REALLY EASLY if you try to TAP in on the side. as in you take a 4'x4' peice and then tip STRAIGHT in on the .5" to 1" thick side. YES IT WILL SPLIT EVERY TIME. Not to mention it doesnt TAP very well at all. You have to extrude it if you want ot do it in that manner. And even then you REALLLLLLLLLY need to use a vice or something to give it a LOT of pressure when tapping on the side. Now when tapping from top/bottem leave so material/space so it doesnt seperate due to the force of the tap. mdf will split every time if you tap it in from the THIN side. OR if your peice is less then 1.5"x1.5" and the tap being in the middle of it. Thats a TAP from top to bottem looking at the WIDE plain side. My suggestion is if your going to tap it from the top to bottem drill a whole just smaller then the threads on from the bolt your going to use. THEN just FORCE it, REAM IT DOWN in there. it will basicly tap its self by means of a rather force full extrusion. IF your going to tap going in from the side you HAVE to run a material removing TAP or use a CLAMP clamped rather tight at the work area when using an extrusion or the extrusion method I just mentioned. I've done a lot of tests with MDF and tapping. To be honist if your wanting to build ALINEMNT squars like xairflyer built AND YOU WANT TO DO IT REALY EASLY!!!!!!! get SOFT pine wood and drill your holes for a TAP run a regular tap threw the whole about HALF or less way. THEN do the extrusion method using your BOLT which will be mounted in the threaded whole. USE the bolt to generate the threads. TRUST ME IT WILL COME OUT NICE AND TIGHT!!!

xairflyer
03-31-2005, 05:34 PM
Must be smaller sheets then, I built my machine with 1" MDF and had no problem tapping it, used it for the centering blocks even though I did have some 1" nylon. Like I said before the tap plus the super glue trick is the secret.

berin
04-17-2005, 11:33 PM
hay xairflyer have you gotten into any advanced stuff with your cnc machine? for example my machine I'm going to use to ether drill or make small driled markers in a plastic side pannel for a computer case I have. Because it neededs better cooling I'll use my cnc machine to make the pilot holes and then do the rest by hand with a drill press. It will be nice to do nothing but just drill holes, that are all accurate with out even trying. I'm still trying to decide if i wan to use SMALL holes which my cnc machine can DRILL ist self OR if I want to use large holes which I'll have to do by hand with the aid of pilot holes.

xairflyer
04-18-2005, 09:46 PM
Yeh I am starting to get the hang of all this stuff, drawing it up in autocad adding a offset then converting it with ACE.
Find that most of the time I have to edit the gcode so it cuts things in the correct order like doing the holes before it cuts the piece out etc.

Made a few different things, mainly out of lexan, cuts well, really need a vacumn table to stop material lifting in the middle.

Items shown below are aviation related, two different sized fresh air vents designed to be fitted into the windshield or the lexan door panel.
Made ones of these before by hand and took me about two hours, these were done in under five minutes !

Large ring is used for holding the bottom of the gaiter around the control column.

Got a Model aircraft plan in autocad that I am going to try and cut out my own kit, need to get a vacumn cleaner first before I start cutting wood or there will be dust everywhere.

Tried to cut out a fin/rudder for another model out of correx (corriboard) but the cutter gets hot and slightly melts it, need to be going faster I think. Try again when I put the 24v supply to it.

The Wizard
04-18-2005, 10:38 PM
Yeh I am starting to get the hang of all this stuff, drawing it up in autocad adding a offset then converting it with ACE.
Find that most of the time I have to edit the gcode so it cuts things in the correct order like doing the holes before it cuts the piece out etc.


Have you thought about using a CAM application to generate the G-Code? SheetCam (http://www.sheetcam.com) for one will take care of your offsets for you and will even cut out the parts in the correct order. It might save you some time compared to manually editing the G-Code.

Larry

xairflyer
04-19-2005, 06:37 AM
Had a look at the web site, it dos'nt actually tell you anywhere what this program does exactly, do I still need to draw the item in autocad first or is it a cad program as well ?

MIKE JEFFERS
04-19-2005, 07:27 AM
xairflyer
try putting things on different layers in autocad that way you can specify the
cut order in ace (priority 1,2,3,etc)or even turn them off
mike

ger21
04-19-2005, 08:31 AM
Had a look at the web site, it dos'nt actually tell you anywhere what this program does exactly, do I still need to draw the item in autocad first or is it a cad program as well ?


You save .dxf's from AutoCAD and load them into SheetCAM. In SheetCAM, you can specify cut direction, offsets, do pocketing, and many other things you can't do with ACE. Download the trial version and play with it. You MUST do the tutorials, though, if you want to have any luck with it. Once you get the hang of how it works, it's pretty easy to use.

xairflyer
04-19-2005, 08:44 AM
Yes Mike good idea should have thought about that, it is why obviously ace mentions priority's !!

Will download sheetcam and give it a try.

MIKE JEFFERS
04-19-2005, 09:21 AM
gerry
yup acad 2002 , my farther in laws just bought 2005 so maybe that'll work
i'll give it a try soon , downloaded sheet cam ,waiting on licence code thingy
any other cheap cam systems you recomend ?
try dolphin partmaster it's quite good.
mike

berin
04-19-2005, 09:50 AM
The secrit to cutting plastic in general based materials comes in two forms. ONE is using low RPM. The finner the cutting bit the slower you have to go. The larger the cutting bit (size relating to the DEPTH of the blades on a router bit) the faster you can cut in both RPM and IPM. The second part is that if you use a WATER cooling system you can run a much higher RPM with a finer cutting bit. which will give you a nicer edge on your cut.

The Wizard
04-19-2005, 10:38 AM
Had a look at the web site, it dos'nt actually tell you anywhere what this program does exactly, do I still need to draw the item in autocad first or is it a cad program as well ?

SheetCam will open DXF files from CAD programs like AutoCAD or HPGL files from art packages like Corel. By using layers for various operations (inside profile, outside profile, holes etc.) you can apply processes to just that layer.

Larry

berin
07-18-2005, 06:40 PM
xairflyer, Well you've had your rig up and running for a few months NOW. Have you gotten into any thing extensive yet? any cool test's trials errors. yOU'D BE amased the stuff you i'm sure have still NOT even thoght of doing that you can now do.

xairflyer
07-18-2005, 09:19 PM
Been making loads of stuff, mainly from lexan and light aluminium.

I just love the machine and spend all the time cutting things out rather than actually finishing it properly, could do with changing one of the leadscrews and changing the power supply (still using 12v) !!

Found my self now thinking "I wonder could I make that on my machine" even if it is something simple (keeping saying to myself, might need to do it again) and tend to spend hours drawing things up in autocad converting it with ace then out to the workshop to cut it out.

Just made a base for a strobe light today out of 6mm lexan, did'nt really need to make it the way I did but it is a first class job and why not when you have the machine to do it.

I have been making up air vents used in aircraft windscreens and doors out of 2mm lexan, sold quite a few so the machine is also starting to pay for it's self. Also made some inspection panels and access hatch's for engine cowlings etc.

Will take some pics and post some of the stuff made.

never did find out yet how to convert a jpg logo so I can engrave it onto a piece of alloy or lexan, will find out sometime.

xairflyer
09-01-2005, 09:30 AM
Thought I could do with adding some pictures of what I have been cutting.
As you can see from the first pic, I am using many different methods of holding stuff down, duct tape works well with some clamps, also used double sided tape and clamps for the light alloy sheet.

Second pic shows the machine cutting out the first part of the aircraft cockpit vents I have been making (see pic 6).

Pics 4 & 5 are bases for strobe lights, If you look closely at pic 4 you can see in the slots a step used to locate the strobe light in place once inserted and turned 10deg.

Pic 7 is a face plate for a instrument gauge that got broke, no limits to what you can do with these machines !!

Noticed I was starting to get a rougher cut and discovered that my Y axis screw had a bit of end float at the trust washer. Went around the machine and vertually all the bolts/screws took half a turn, so it pays to do a bit of overhaul now and again !!!

ViperTX
09-01-2005, 10:33 AM
Absolutely amazing...just shows you what you can accomplish if you just do it!

zoltan
09-01-2005, 10:38 AM
Hi,

May I ask you what RPM, feed rate, plunge rate and what bit (cutter) do you use? What is the pass size - how deep do you cut on one pass? and What is the thickness of material you cut? I am referring to plastics as I have seen in the pics.

Thank you,

Zoltan

xairflyer
09-01-2005, 07:49 PM
I am not cutting very fast as I am still using a 12v supply on my HobbyCNC board, however I think it is still fast enough for a mdf/pipe machine.

I do all my cutting in lexan at 250mm (10ins) minute the first plunge into the material I set at f100 (4ins min) after that it does everything at f250.

My router is a B&Q jobbie (working very well) which has a varible speed from 20,000 to 30,000ish
The speed control is numbered 1 to 10. I cut lexan at 2 or 3 and aluminium at 10 (flat out).

I found that 2 flute cutters are the best (slot drills) 2mm and 3mm are the ones I use the most, tend to setup all my offsets on my autocad drawing to suit a 3mm cutter, unless the slot or hole is smaller than 3mm. Have on some parts added in a tool change to the gcode so I can do most of the heavy cutting with the 3mm.

Mainly cut 1.5 to 6mm lexan. 6mm is great because it is more ridgid, the thinner stuff is hard to keep down, especially if you are cutting out a narrow strip or ring. Need to build a vacumn table.

Used to take two passes on a piece of 2mm lexan, still would on a more detail part, but have found that the machine will easily cut the 6mm stuff in one pass if I want, but I would worry more about the cutter breaking especially ones smaller than 3mm.

Would definatly recomend cutting plastics especially lexan (polycarbonate) on a new machine while you are learning as they are easy cut, and you don't have any dust, plus there are loads of great things you can make.

zoltan
09-02-2005, 02:34 AM
Thank you. I really appreciate. Sorry, but What is "ish"?

Zoltan

triticale
09-02-2005, 11:39 AM
"Ish" is an ending put on a number to indicate imprecision.

In the example above, the router spindle has a top speed of approximately 30,000 RPM.

berin
03-20-2007, 11:54 PM
So how goes the project? I'm just starting on my new cnc machine. Its going to be $^%#$% massive!! I'll be posting pictures soon but to give an idea, my work area is going to be about 4x4' with 16-22" of Z plunge, I'm also going to make a 2 axis Z head unit so I can do 3d stuff with it,This thing is going to just be HUGE. Only thing holding me up right now is the lack of money. USA maine SUCKS. Nothing in this area and is so hard to find an even remotely close to being an except able job blaaaa.. But below is the first image Of the first major part for my new cnc machine I have produced. First thing I can tell ya is that it may not look like much but its also a bad angle. Ok the vertical supports are 3/4" ply, its just for something that is easy to screw into. There are 1/8th angle support brackets that are going to be bolted to 4x4' vertical angle iron running on the vertical parts to make it very strong. The white cross bar is already very strong being 2.5" thick wood/glue composite stuff that came from a super heavy door I cut down. Very straight very strong. I'm still going to be adding some steel to make it stronger. When this machine is finished I should have no problems milling metal.
http://berinslaptop.googlepages.com/MajorYaxis.JPG

xairflyer
03-21-2007, 09:41 PM
That machine is going to be BIG, just like the picture you posted had to scroll the screen a cross to see it all !!

xairflyer
11-29-2007, 01:09 PM
Decided to come back again and have a look at what is going on in the diy CNC world as I want to build a new machine with a small robust table to work with aluminium.

Amazed what new machines have been built since I built mine 4 yrs ago.
My machine has done a huge amount of work and deserves a strip and rebuild as it has worn a bit, but amazing how accurate it still is.

xairflyer
12-03-2011, 08:17 AM
Back again, :wave: wonder if all the guys who used to reply on here are still around?

My machine has been going great and used all the time.
Recently I decided to finally change my Y axis leadscrew to 12mm allthread like the other two axis and also upgrade the motor to the same vexta PK266.

I am now having PSU problems with the PSU cutting out again as soon as I switch on. The new motor is 2A and the original was only 1.4A.
Looking back through the posts (long time ago now) I see I had the same snag with the PSU cutting out when I used a bigger motor.

Looks like I am going to have to change it and always had intended to go 24v but got lazy with the whole CNC thing as my machine has been working so well.

My present computor PSU is 400w and each motor is 2A the PSU is supposed to give 12A but obviously not, wonder if I changed the load resistor value on the 5v line would it help?
I have some stuff to cut and would like to get it going for now, then I could look at sorting it out once and for all with a bigger 24v supply.