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wcarrothers1
11-05-2010, 12:39 PM
Well I started building a little and figured I would start posting. Probably will be a long process but hopefully will come out and be more capiable then my first machine.

As with my last machine I started building the gantry first. So far I have the 1" plate 80" long with rails top and bottom attached. Rails extend past the end of the plate ~3.5" on top and 1.5 on the bottom. thought here is this will alow me to spread out the rail trucks a little more then other wise and might reduce any flex when the gantry is in the middle of travel.

Bottom trucks are spaced 13" apart and the tops will be ~16".

Pretty happy that I got all the holes drilled for the rail install with success and also made up the bottom plate that the front Z plate will attach to. And it came out nice.

I didn't happen to have the CNC bridgeport when I built my other router mill so hopefully I'll be able to produce some nicer parts for this machine.

Gantry weighs in at a 125lbs includeing aluminum plate and rails. Will probably top out around 300lbs once completed with dual Z's and motors..

Will be using THK KR guide actuators for each Z. Still have not decided if I will have the servos drive the ball screws they have or if I will attach gear rack to them and drive the Z's with servos and planetarys. The reason for considering going with gear rack on Z is the ball screws on these actuators are about 1.25 turns per inch of travel. which I'm not sure will give me the resoloution I want on Z. Still have some calculations to do on that I guess.

Will be using Moog L180 servo amps and G series brushless servos on this machine.. Interfaced with a Kflop/Kanalog setup. So should be interesting.

b.

wcarrothers1
11-06-2010, 11:18 PM
Some progress on the Z axis..

This is the front plate. all holes on the front are for attachment of the KR slide. I can move it up or down a bit on the mount. Basicly the center is where I'd be in the travel which will put the collet nut of my ekstrom carlson spindle maybe .1 or .2" below the bottom attachment plate..

Figured if I mounted other spindles I might want some amount of adjustment.

The ears on either side of the top of the plate will have holes put in to alow mouting of my 10:1 thomson ultra true planetarys (think they are size 060 so they are pretty small) to be installed if I use rack and pinion on to drive Z.

Ignore the extra holes in the plate which are skattered around (I borrow some of my metal from old equipment I find around. Figure I save some $$ and also good recycleing:)

b.

wcarrothers1
11-08-2010, 08:37 AM
Couple more pics. Ended up re-drilling the front plate so the trucks of the KR slide can mount directly to the plate rather then having the adapter on it. Seems it would be better to do it that way I think rather then using the stand off pads if I'm going to convert it to rack/pinion rather then using the ball screw. Also lowers the profile a bit so it does not stand off the front of the plate quite so far.

b.

harryn
11-08-2010, 10:24 AM
Hi, that should make a sturdy setup, at least if I am looking at it right. It is early morning, so anything is possible.

The screw vs rack question is always an interesting trade off to struggle with. The nice thing about a screw is that it tends to support the Z axis when it is powered off, while other approaches need some other method to keep it from dropping down.

wcarrothers1
11-08-2010, 10:05 PM
The screws on these slides are like 1.25 turns per inch. So very steep screw, never in a million years would the screws on these stop them from crashing the table. Heck my 5 TPI screws on my 4x8cnc hardly slow it down (if it were not for the springs I added) and it still sags a bit.

How ever, the moog servos I have for the job have built in magnetic brakes which are their for exactly that reason. So would probably be fine with the screws.

I just have these really cool (brand new and identical) thomson ultra true 10:1 size 6 planetarys I collected (basicly new on ebay for 65 bucks each I think) and think they would go perfect.

Also if I wanted to mount the Z with out the stand off adapter thing (ie screwing directly to the slides rather then slide to adapter/stand off to plate) I'd have collision problems with the top of the Y rail..

Anyway I always liked my long axis rack on my other machine the best (and actually it's way more accurate not to mention faster then either of my ball screw axis) so wanted to go rack with planetary all the way around this time.

Only down side is lately it seems all the good planetarys have dried up on Ebay. But at the moment I have collected plenty of units for this job.

2 size 06's will run the Z 10:1's
1 size 090 Apex dynamics will run the Y (gantry) 10:1 (I have an identical unit running my long axis on my 4x8' Think they are <5 arc accuracy

and I scored a right angle low arc (<2 arch accuracy) apex unit size 010 which is a 14:1 which will drive the Z. If I don't steel the one off my 4x8 in order to have identical ones running the bigger mill..

Still alot of work to go into this machine before it's done..

As the gantry is I can only get about .005 - .009 maybe of rotational flex when it is at the center of travel. I get zero flex up to down at center. So it's darn stable with just the 1" plate but think I will run some alum or 80/20 the length to firm it up or give spots to mount stuff to the back side..

Have to start working on the side plates..

After this is done I will have 2 of these rails with 4 slides left over as well (orignaly manged to collect 6 rails and 12 slides). So might be able to upgrade the old V bearing machine later to.. But don't know if I'll bother. This machine should outright replace the old in just about every way if the drives and servos operate as well as they should.

b.

wcarrothers1
11-28-2010, 06:28 PM
Well here are some more pics of the gantry. I have the other Z axis done as well but don't have it mounted as I am still waiting for the servo to plantary couplers I ordered to show up..

I think things are looking pretty good so far. Now I have to dissassemble the gantry and do more drilling on the large 8x80x1" plate. Drilling attachment holes for the 80x20 such for mounting the X axis rack..

Enjoy..

b.

wcarrothers1
11-28-2010, 07:20 PM
Thing I can't exactly decide.. Attaching the gear rack for the X gantry. You can see the rack in the second pic. It is ssitting on top or some .5" by 1.5" bar stock aluminum. Idea was to screw that to the large gantry 8x80 then screw the rack to the top/edge of it. I was going to get .75" by 1.5" strips to do this with but I clicked the wrong item on ebay and got .5 wide. This part was not really suposed to stiffen the gantry or anything but just can't decide if I should get the .75 or if the .5 be good. My fear is bolting the .5 wide to the gantry then the rail to the top edge of it will flex a bit. I'm thinking it would be pretty stiff though..

b.

CarveOne
11-29-2010, 06:56 AM
Thing I can't exactly decide.. Attaching the gear rack for the X gantry. You can see the rack in the second pic. It is ssitting on top or some .5" by 1.5" bar stock aluminum. Idea was to screw that to the large gantry 8x80 then screw the rack to the top/edge of it. I was going to get .75" by 1.5" strips to do this with but I clicked the wrong item on ebay and got .5 wide. This part was not really suposed to stiffen the gantry or anything but just can't decide if I should get the .75 or if the .5 be good. My fear is bolting the .5 wide to the gantry then the rail to the top edge of it will flex a bit. I'm thinking it would be pretty stiff though..

b.

If I follow your description correctly, the bar acts as a spacer to raise the rack upwards for full engagement with the pinion gear on the motor. The 1.5" dimension is flat against the gantry beam. It appears that the gear in the second photo is not full engagement, which is not desirable. The choices I see are:

1. Order another bar of the correct size.
2. Order a .25" x 1.5" bar to sit on top of the .5 x 1.5" bar.
3. Make .25" thick washers to install at each rack mounting screw location. The washers can be round or square.

As long as the mounting screw locations are fairly close together and the screws are tight you probably won't see much flexing of the rack itself. My own .5" square racks are mounted with rack clamps that are 12" apart and the racks are not flexing, but if I had been drilling screw holes in the racks I would have spaced the screws about 8" apart.

CarveOne

wcarrothers1
11-29-2010, 11:44 AM
I'll have a picture of this. I know I was just rambling last night..

My current drawing is to busy to post and try to describe. But in picture 1 and 2 you can see a small section of the X rack which is on top of the .5" thick by 1.5" deep bar which runs the length of the gantry.

Under that alum bar is some 80x20 as well. Basicly a 6ft piece of 3/4" face width rack will be screwed to the .5 thick bar such that the teeth will hang off the end and mesh with the pinion and planetary. The .5 bar will be screwed to the gantry from the front side.

Over all I think this setup will be fine. Just stinks seeing I was orignaly going to use .75 thick stock and 8mm screws to fasten it to the gantry where now I'll be doing 6mm screws. Both harder to drill (smaller bit) and such.. Considering just ordering some .75 stock and sticking with the orignal plan but can't decide.

Rack will be screwd to the .5" piece with a 6mm screw every 5" I think. Also might back up the rack with some flat steel stock (can also see that in the pic) which would be spot welded to the back of the rack.

Will consider your 8" recomendation as that might be less screws and threading.

hopefully this aluminum stock will drill well with out getting gummy.

b.

CarveOne
11-29-2010, 01:12 PM
I'll have a picture of this. I know I was just rambling last night..

My current drawing is to busy to post and try to describe. But in picture 1 and 2 you can see a small section of the X rack which is on top of the .5" thick by 1.5" deep bar which runs the length of the gantry.

Under that alum bar is some 80x20 as well. Basicly a 6ft piece of 3/4" face width rack will be screwed to the .5 thick bar such that the teeth will hang off the end and mesh with the pinion and planetary. The .5 bar will be screwed to the gantry from the front side.

Over all I think this setup will be fine. Just stinks seeing I was orignaly going to use .75 thick stock and 8mm screws to fasten it to the gantry where now I'll be doing 6mm screws. Both harder to drill (smaller bit) and such.. Considering just ordering some .75 stock and sticking with the orignal plan but can't decide.

Rack will be screwd to the .5" piece with a 6mm screw every 5" I think. Also might back up the rack with some flat steel stock (can also see that in the pic) which would be spot welded to the back of the rack.

Will consider your 8" recomendation as that might be less screws and threading.

hopefully this aluminum stock will drill well with out getting gummy.

b.

6mm is close to 1/4" and I think they will be plenty strong. Especially if they are a good quality hardened screw. I have a smaller rack and I think I used #10 socket head cap screws (from Fastenal, not generic stuff from the household hardware section at Walmart :D) on my Y axis beam. I made rack clamps for both sides of the X axis.

CarveOne

wcarrothers1
11-29-2010, 06:16 PM
My Z axis rack is held on with 1/4-20 screws. The X will most likely be held with 6mmx1 . That is the metric equivlant of 1/4". And the biggest I'd want to drill into my 3/4" face width rack anyway. really only .56" of space between the back of the rack and teeth bottom so would not want to go bigger for attaching...

I ended up getting a couple boxes of 8mmx1.25 hex bolts while collecting parts over the last year for this build.


So that took me in the direction of doing much of this in metric screws. So will use that size for attaching the .75x1.5" flat to the X axis plate. I ended up ordering the .75x1.5" stock so I continue with the orignal plan rather then going to the .5" which would probably have been fine but..

Doing alot of this in metric is sorta sad seeing I have a 100's of different size standartd taps that I got in a cabinet I purchased at acution (basicly a life supply of metal taps) But all standard..hehe

b.

CarveOne
11-29-2010, 10:24 PM
Going with the original play is probably best. The .5" x 1.5" piece is not wasted money. You'll have it when you need it later. I'm getting a good selection of excess stock this way.

CarveOne

wcarrothers1
12-12-2010, 10:51 AM
Done some more work on the gantry.. have some more machine work to do for the servo/planetary mount for the long axis drive. But waiting on some parts to show up.

basicly here I have most/all the holes drilled for the gantry 1x80x8 section. The .75x1.5 bars are drilled and bolted, also have the rack for x able to be screwed on (but not on in the pics because I have to machine the squares on each end as they are in the way right now)..

Sides are sloted screw attachments are drilled and blocks are attached for the long axis rail trucks..

Also have some of the long axis drive items on just for show.

b.

wcarrothers1
01-10-2011, 09:11 AM
Got some more work done on the gantry build..

Also got my limit switches installed and started tinkering with actual gantry motor movement controlled by the L180 moog drives, driven with the Kflop / Kanalog hardware. Very cool stuff so far, seems to work very cool together. Very configriable with dynomotion's C code aproch to building configurations. Takes a little doing to sort it out but I think once it's all up and going the features that can be built into the controller will make this a very cool machine.

Was getting a little concerned with over all gantry weight untill I started driving the x axis under kflop Kcnc and Mach 3 control. The speeds it can move side to side are impressive. Wich made me see. that the gantry weight (being around 250-300lbs finished) will not be that big an issue. Since the X asis parts when moving will be pretty light. I'll just end up rastering carvings along that axis where on my other machine since x is the slower axis I raster along Y moving the gantry.

Anyway hopefully actuall performance will be as cool as what I've seen so far.

Still have to build the rest of the table.

b.

CarveOne
01-10-2011, 09:32 AM
Looking quite impressive..... :)

CarveOne

CNCMAN172
01-19-2011, 03:28 PM
Wow, you have a nice build going. Very nice construction and using heavy duty servo motors with all that aluminum should be extremely robust. Very Nice. Keep up the good work.

Russ

LeeWay
01-19-2011, 04:43 PM
Totally in agreement. Very cool.
Put tracks on it and call it a tank. ;)

wcarrothers1
01-20-2011, 09:23 AM
After using the old router mill to mark all the hole locations (think 47 holes per rail) for mounting the long axis rail. I saw first hand the amount of angle the rail would be on if mounted to the surface of the hot rolled steel tube. Needless to say the suraface was pretty dished and amounted to around maybe a .5 deg tilt of the rails.

Figured I'd regret not having the 136" long rails ground but really can't farm that out..

So looked toward my not so used bench 16/32 drum sander and figured I'd just take a lot of passes and take it easy.

Well not easy to mussle around those long beams, but after alot of passes and a few strips of 80 grit paper (perhaps should have used 60 or less though) I got results I was looking for.

Both rails thickness wise are with in .006 ish and measuring random thickness in the length are ~.002-.004 in thickness varience. So I think they came out great. And as you can see, The rails are now square with eachother on the surface.


Kinda got a weird setup with the drum sander. The extra blower motor (red thing) aimed at the sander motor kept it cooler during the hard operation. Shop vac took care of most of the iron dust, and did not cause a fire:)

Anywho anyone thinking about needing to true their steel can get away with it on a wood working drum sander...

After seeing the results, kinda makes me want to feed all my steel beams through my drum sander. But I will try to resist, Took about 2.5 hours to grind down each beam to my liking..





b.

CNCMAN172
01-20-2011, 09:34 AM
Wow, I have a drum sander similar to what you have but would never have dreamed of putting steel tubing through it. :) Amazing you got it so flat because most of those drum sanders sag slighted because one end is open so you cut deeper on one side versus the other. I guess since the material as narrow enough you did not get much variation. Awesome Job.

It certainly looks very flat and true now. Keep up the good work.

wcarrothers1
01-20-2011, 10:03 AM
The process of runnig the steel is pretty long.. Several initial passes are just to get things started I think would be enough to discurage anyone that it would actually work..

I didn't count the number of passes I did. But it was alot..

Also far as the "sag" goes, they do I guess sag. but can be tuned. I'm not exactly proud to say my drum sander is a ryobi. I always wanted a performax (now Jet) but timing was not right to afford that premium..

course on the other hand if I distroyed the ryobi in the process of doing this I would not feel as bad as if I killed a performax..

But anyway, The process of getting it square (dispite sag or heavier cutting toward the inside) ends up nulling it self out when you flip and rotate the steel tube..

Basicly you do a few passes inserting 1 end first, then rotate it and run the other end in. then flip and repeat..

Now I just have to resist wanting to true up all my other square tube for the build..hehe


Consumed maybe 3 strips of 80grit paper and 1, 120grit for the process.

The funny part of this, is I know people with the ryobi's who have had conveyer drive motor gear failures and all sorts of other issues with their units, and mine is sitll all orignal (probably 10 years old now and run a LOT of wood stuff in it's life) and now feeding steel beams through it..hehe

b.

CNCMAN172
01-20-2011, 10:19 AM
Yeah, rotating the parts end on end certainly helped to keep things even. Know what you mean on the Performax as I picked one up used years ago and would be afraid to damage it as it does a nice job. But, even the performax has a sag and I have adjusted it several times, but I do the same thing with rotating the stock to keep it more even.

Anyway you did a great job and three rolls of 80 grit was cheap to get it right in the long run.

wcarrothers1
01-30-2011, 07:58 PM
Started welding the chassis..

Basicly I align and clamp the sides together and start welding the parts on. This insures everything is in alignment and is much easier to do this way then say trying to align the 2 side pieces when they are on either side of a machine. Really I have no idea how people do that. But I've done this successfully before so works for me..

Does require a ton of clamps but insures the 2 sides are very well aligned.

Last I'll weld on the length long pieces on the legs which support the table then I'll flip them over and put the middle in.

b.

wcarrothers1
02-01-2011, 10:41 PM
Trying to decide... If I want/need to re-inforce the top any more then it is before I flip the chassis over..

Basicly you all have seen the rails in previous pics which are mounted to .25 thick 2x3 hot rolled. Rails are quite large and should spread the weight of the gantry pretty good.

Distance between the verical legs is 59" And on the bottom I have welded a 3" by .5" thick steel beam and also gusseted that every 11ish inches between the 59" gap. Shoudl take some side view pics but think everyoone can figure from the pics how it is.

Anyway the question is, should I weld up another 2x2 x maybe .188" wall thickness square tube to the bottom of the 3" beam or should I just leave it as is.

The gantry will rest on the large roller bearing blocks. they are about 5" wide each and will mount to the large aluminum plate. The distance from one end to the other of the blocks will be about 13" so again spreads the weight out and that alone should not really alow the steel rails and such to flex much.

Gantry weight will probably top out around 300. although the amount of weigt each side will carry will vary a bit depending on the location of the X and Z parts. . I can no longer pickup 1 end of the gantry unless the Z/X parts are slid to the opposit side of the X axis.. So it's pretty heavy. For sure heavier then my orignal machine.


Anyway so should I add more girth to it or leave well enough alone.. (suppose I could always weld in more later although now is the time in order to keep everythine in good alignment.

b.

wcarrothers1
02-10-2011, 09:39 AM
Hung the gantry today..

.. Wow do real linear rails (rather then v bearings like my orignal machine) move smooth.. I can move the gantry with 1 finger easy.

Was thinking I might have speed issues with the heavy gantry but with the easy movement I'm thinking the servo motor I have hung on it now is way over kill. Might switch back to the same motor I'm using on the X axis But I guess it does not really matter if it's a big motor. Only anoyance is the bigger motor (like the ones for the Z axis) has a electric brake on it. Those can be anoying if you want to move the gantry manually as you have to energize the brake. Good to have for a z axis to prevent the axis from droping on loss of power but for other axis probably not neccessary. Plus makes it so you should drive the Z and Y axis brakes independantly, so you can release the Y axis and move it with out droping the Z.

Anyway hope the pics give ideas of how to assemble a machine like this. Basicly followed this same build order with my orignal machine and this one.

I think the main advantage is, the machine can be broken down if you need to move it, Basicly gantry gets removed, table gets detatched, reinforcments between legs removed and the 2 sides are free to go.

How ever in this case the table support and side leg assemblys are quite heavy. But still with a few people could be removed from my basement. And can be assembled by 1 person (with only slight risks of being crushed..hehe)

b.


b.

wcarrothers1
02-24-2011, 09:31 AM
Just a quick update. And some pics..

Welding up the table. Still have some supports/cross brace stuff under to do as well.

trying to decide how to lay out the MDF table. Will be in pieces and think I'll do a strip up the left and in the back with 1 solid piece in the lower left. Thinking I should have split the table in half and put the seam in the middle but hopefully this will work out ok..

CNCMAN172
02-24-2011, 10:17 AM
wcarrothers1,

Wow you are doing a first class job on this build. Great effort very nice. Looks like this will be a beast. When you think about your MDF table I have seen several approaches and you will need to seam if the table is too big. I think CarveOne did a similar type build and he actually drilled at tapped holes about every two inches or something on all the cross members that the MDF table would sit on and then installed leveling bolts. These looked kind of like levelers you might find on the bottom of piece of equipment. Anyway he found shallow ones and this allow him to fully level the table very accurately because he could put a dia indicator in the spindle and jog around the table and make minor adjustments. Just a thought. You might want to also consider two layers of 3/4" MDF and stagger them and glue them so you have more of a solid type table top.

Russ

wcarrothers1
02-24-2011, 10:47 AM
My 4x8 is basicly the same design structure wise (but not as good far as the linear rails go) I zeroed the machine, had it lay out the drill holes for location of attachment. Tapped them all in the steel.

Placed the MDF on, Drilled the holes. Then counter sunk and screwed the first sheet down. Surfaced with a 2" surfacer. I think I might have sealed that first sheet with some poly then layed the second sheet on, had it drill the holes and screwed it down.

Later I ran a slot path in that second sheet which I put T rail in.

I've been collecting 4' t rails from the wood workers store every time they run a special for 19 bucks each. I have a lot of sections over the course of doing that for a year. I've got bags of the T bolts to. so will be adding T slot to this table all over to. Nice thing about their updated T slot is the depth is not as deep as the orignal stuff I did my first machine with.

Hopefully the analog moog servo drives with the Kflop/Kanalog setup will prove to work well. That is new territory for me as my other machines are Geckos.

Did the big moog servos thinking with the weight of the machine they made sense. But to be honist, pushing this gantry around, It moves smoother and easier then machine 1. So it could have probably been plenty happy being a DC brush servo + gecko machine.

But anywho..

b.

wcarrothers1
02-24-2011, 10:50 AM
Also scored a killer deal on ebay for the wire guide chain. 75 bucks + 10 shipping for double what you see being used in the pics.. was a crazy great deal. Couldent believe the seller took my offer. (it was worth the 100 he was asking on the buyit now) And probably worth 3x given the amount..

b.

wcarrothers1
02-24-2011, 10:59 AM
The table on my first machine has stayed intact (with some minor ware) for 4+ years.. I lay one of those 3/16" peg board/hard boards on top when I do through cuts. Makes for cheep protection for the table. Think I've only had 1 crash drilling into the table itself over that time..

Only thing is if I were to re-weld the side beams on again I would have stuck them down maybe .5 or .75". Still I should have ~8" of gantry clearence. But probably better that I didn't give more by mistake. As I gave my self way to much on my first machine (more then I've ever used anyway at ~11") and the result of that is more flex then I would otherwise have.

b.

CNCMAN172
02-24-2011, 12:53 PM
wcarrothers1,

Yeah love the wire guide stuff it really makes a machine look professional and keeps things nice and neat. Everytime you build one of the machines you realize stuff you could have done better. Still man you have a great looking machine should provide years of service.

Russ