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bigz1
04-15-2006, 06:34 PM
I hope to build a first CNC Router to fit 1400 x 600mm using mostly 18mm MDF. I intend to cut mainly balsa and plywood with the occassional bit of lithoplate for RC planes. Attached is a rough design. I am limited on time and finances so I have tried to make the design as simple as possible. I have also enclosed a few features to try and overcome the budget/time problem. The 2 main ones are twin bar design either side of the gantry plus a groove on base and top/bottom of gantry to support rails using open bearings to guide. Any suggestions would be most welcome.

I would also appreciate advice/links on drivers and software. As a cabinet maker I can handle a panel saw/CAD package but when it comes to electrionics all I know is one end of the soldering iron gets hot.

Liam

ViperTX
04-15-2006, 06:48 PM
Okay....using supported open bearings is a good start, I would look at using ACME screws for each axis, go with steppers (see some of the vendors on this site for an inexpensive stepper and driver package).

The rest of the frame and gantry can be made of MDF to keep costs low.

This will give you a good machine.....a better and slightly more expensive then the JRGO that alot of the users on this site have or are building.

bigz1
04-16-2006, 05:21 PM
Thanks for the posistive feeback ViperTX. I have revised the design slightly. I will also be using open bearing for the upper rail(something similar to Joe's design). The blue rod represents the ACME screw. What would you use to build the frame and gantry? I was thinking conformate screws and PU glue.

joecnc2006
04-16-2006, 06:46 PM
With the lead screw on top you would be limiting the z axis travel and have a hard time fitting in the z axis motor. for learance under the leadscrew.

bigz1
04-17-2006, 07:12 AM
Hi Joe. Yep I think your right. I want to still keep the lead screw on the top as I am limited on height in my workshop where this is going and was trying to save space by discarding the torsion box for the base(Its going on an accurate flat & level workbench that I cant rip out). Could you give me a rough height for a stepper and mount? I will see how much more space I can gain by lowering the y axis torsion box. I am only looking for approximately 80-100mm z travel anyway. An alternate idea might be to put the leadscrew offset to one side but I think this might would be a bad idea?

Joe when I get time to convert the attic I will be making your 2006 model or by then you might have an even more incrediable design.

joecnc2006
04-17-2006, 04:16 PM
If i understand you, you will have 4 rails one in each corner as shown in picture with red circles, the I would install two leadscrews on the sides as shown in blue and remove the one ontop "X'ed" out. Use two small motors slaved for the X Axis. which can be installed on the outside overall frame.

Joe

bigz1
04-17-2006, 04:44 PM
Got it in one Joe. I will follow your advice but couldn't I put the leadscrews inside by placing them slightly lower down(again lack of space!).

joecnc2006
04-17-2006, 08:24 PM
The lead screws are ment to be interior, but anything is possible you just need to design for it.

bigz1
04-19-2006, 05:02 PM
Put a proposal to the the boss today. Basically he has agreed to pay me £350 to build my machine and if its successfull build him something larger!!! Just to pick your brains again. What do you think of using square(25mm x25mm) bright steel bar instead of round bar to run bearings on similar to Joes design for the X and Y axis. Still using a routed groove to support the rail. This maybe a dumb question but how do I slave the 2 small motors?

bigz1
04-19-2006, 06:52 PM
Just bought this on e-bay($212 plus P&P). Steppers are Nema 23's. Seemed like a good price as the first lot I bidded on went up to $310. So I guess this is for real now.

joecnc2006
04-19-2006, 07:58 PM
Just bought this on e-bay($212 plus P&P). Steppers are Nema 23's. Seemed like a good price as the first lot I bidded on went up to $310. So I guess this is for real now.

What are the specs of the motors?

bigz1
04-19-2006, 08:02 PM
3 ASTROSYN STEPPER MOTOR NEMA 23

1.8 DEGREE STEP (200 STEP PER REVOLUTION) FULL MODE

0.9 DEGREE STEP (400 STEPS PER REVOLUTION) HALF MODE

6 VOLTS

1.2 AMP PER PHASE

5.4 OHMS PER PHASE

116onz/INCH TORQUE

6 LEADS CONFIGURABLE AS UNIPOLAR OR BIPOLAR

6mm SHAFT 1/4 INCH PER 3/4 INCH LARGE

I was thinking maybe buying a larger 200onz/ inch torque for the z axis?

bigz1
04-19-2006, 08:28 PM
Plus the specs on the rest

3 MECHATRONICS BIPOLAR STEPER MOTOR DRIVE

BIPOLAR DRIVE FULL SPEED AND TORQUE

INPUT POWER SUPPLY 12 TO 18 VOLTS

SINGLE DC SUPPLY REQUIRED

MAX. 2 AMP. PER COIL

FULL AND HALF OPERATE MODE ( 200 STEP/REV. AND 400 STEP/REV. )

OPTICALLY ISOLATED STEP AND DIRECTION SIGNALS (NO CONNECT DIRECT TO YOU PARALLEL PC PORT ALL PC CONNECTIONS ARE PROTECTED NO RISK

DISABLED INPUT CONTROL

MOTOR CURRENT IS ADJUSTABLE BY POTENTIOMETER

CHOPPER POTENTIOMETER AJUSTED

INTEGRATED HEAT-SINK NO COOLER SYSTEM IS REQUIRED

ONE DB25 BREAKOUT BOARD

ONE 8 FT PARALLEL DB25 PC CABLE

ONE COPY DIAGRAM OF WIRED

bigz1
04-23-2006, 06:52 PM
What ACME thread size would you recomend for this project? I was thinking 1/2"-10 ACME 5 Start (2 turns per inch)in conjunction with dumpsterCNC parts.

joecnc2006
04-23-2006, 07:21 PM
you can use acme 1/2-10 one start, with the hobbycnc board, 200oz. motor kit, and i would go for his whole kit to get the power supply parts also, like mine and cutting at 80ipm. which is pretty fast for a DIY Home cnc machine.

altho you have the motors and controllors, it looks like they are only 80oz.in, maybe 100oz, you will find these will not be powerful enough for the 2 start leadscrews, thats one reason i recomended the 1/2-10tpi, Also do not use anything less than 24vdc, you will be disapointed in speed with that.

Also Dumpsters parts the anti-backlash leadnuts, and also his new ACME Thread Clamps will work very good, i bought two of them to test and definately going to get more now.

Joe

bigz1
04-27-2006, 05:50 PM
Still playing with the design while purchasing hardware. Added a torsion box. With this design I am trying to maximise the cutting area with the limited amount of space I have. Once I I have more components I will be able to decrease the size of the dead zones in my design. Joe I take it you put your x axis stepper on the rear of the gantry in order to try and counter some of the weight of the router, also do you need to buy flanges to attach DumpsterCNC's anti-backlash nuts? Red = y axis bearing rods Blue = thread.

Bought a pair of TKH linear rails(120mm travel) for the z axis for £40 inc P&P. Also about to place an order with Enco for thread, Ali Angle and LoveJoy connectors. Will probably buy the HobbyCNC 200oz 4 axis kit and sell the other one. Really appreciate your advice Joe. Thanks.

Liam

bigz1
05-05-2006, 03:06 PM
I have noticed that the LoveJoy connectors have quite a bit of play(approx 0.5mm). Won't this cause backlash? I will probably use paper shims to reduce this or does anyone produce replacement parts for the rubber inserts?

Also just bought the HobbyCNC 200oz 4 axis kit.

joecnc2006
05-05-2006, 03:23 PM
I have noticed that the LoveJoy connectors have quite a bit of play(approx 0.5mm). Won't this cause backlash? I will probably use paper shims to reduce this or does anyone produce replacement parts for the rubber inserts?

Also just bought the HobbyCNC 200oz 4 axis kit.

Yes I made my own out of HDPE, no play in them now.

I have made a ton of them. and have them sitting around, sell it for 1.00 each..

Joe

ShayArnett
05-05-2006, 04:27 PM
I am starting out with a jgro style machine, I too want to design my own, but there are a lot of things to consider that I don't think i would have even imagined until I started scrapping parts if i had built my own design first. And now that Joe has developed his 2006 model, I doubt I will do my own design at all, since it fixes most of the issues with the jgro design.

I'm all for seeing alternate designs so by all means keep on keepin on, but maybe you would want to consider starting with a jgro too see which areas you want to improve on the most, so you don't over complicate/engineer an area that might not need it.

bigz1
05-05-2006, 05:22 PM
I hear what your saying ShayArnett. It reminds me of my foreman's favourite acronym 'KISS' = Keep it simple(or if he wanted to be insulting he would add stupid). The most daunting part for me will be the electrics and the software(yet to be decided).

I build kitchen doors and cabinets for a living so the build will be the easy part. I have designed and built a variety of machines in the past including a hobby panel saw, Hoffman jointer(Cuts slots for plastic dovetail joints), moulding and sizing machines for solid timber doors even a simple glue applicating machine. I would post pics but none of the above are CNC.

As for the design I think I am favouring the 2nd one. It will be extremely easy to build requiring only a panel saw and a router and I have taken into acount the limitation of the accuracy/precison these machines provide(I wil be using stock 60 x 30 mm MDF moldings to buid the torsion box, heavy but straight and true). The Jgro is an excellent basic design but I like the idea of the twin rails for the y axis. I cant wait to see what Joe comes up with for handling 8 x 4' sheets.

randyf1965
05-05-2006, 05:30 PM
I built my x-axis gantry 66" wide between supports so I could rebuild the y-axis to 8' without having to rebuild x and z also.

I am planning a Joe 2006 style setup for the y-axis, I don't see why the design wouldn't work

bigz1
05-05-2006, 06:05 PM
Good idea Randy. I agree Joes design is ideal for sliding large sheets on mine would be inappropiate design for larger pieces.

This machine is for my own small hobby stuff(got the funding from the boss as I said it was for reaserch purposes). I just spaced the y rails as far apart as possible to reduce racking caused by the tolerances the saw and router introduce. I have been offered a pair of TKH rails for the x axis, unfortunately they cost £140!!!(tempted though) :cheers:

bigz1
05-05-2006, 08:07 PM
I have quite a few 240 volt laminate cutters with mounts(used on laminate edge banding machines) lying around at work. RPM is fixed but does anyone make something that can be added to vary the revs?

ShayArnett
05-05-2006, 09:22 PM
HF had their router speed controls on sale in the last sale paper i got.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43060

$9.99 online

bigz1
05-09-2006, 04:58 PM
Thanks for the link Shay. Unfortunately the shipping price was a bit steep $31.00. So I will be buying local (550W Ferm router variable speed 6,8mm & 1/4 collets = £24.99).

I am undecided which Software to buy what would you recomend? I would like to eventually try some 2 1/2D stuff. I currently use Solidworks and for 2D AutoCad.

bigz1
05-20-2006, 06:56 PM
Recieved HobbyCNC 200oz Stepper Kit from Dave yesterday. Spent all evening soldering(How do you guys do it in an hour or less) ready for testing tommorrow(fingers crossed and will mutter a prayer beforehand, whilst covered in an assortment of lucky charms). I was really apprehensive as this is my first time I have soldered electrical parts. Spent a bit time on the web for reasearch and 10mins practicing on an old RC servo(First time perfect. Shiny volcano shaped joints everytime). So far I have found Daves instructions both easy and simply to follow.

Is it normal for lead free solder to eat away at cheap soldering iron tips? :confused: :confused:

bigz1
05-22-2006, 03:42 PM
Tested the circuit today. After the sparks stopped and the smoke disappered the meter showed 5.2V as per instructions. SUCCESS.

:banana: :banana: :banana: :banana: :banana: :banana: :banana:

To quote: A little knowledge is a dangerous thing. No problems their.

bigz1
05-24-2006, 07:51 PM
Nearly all the parts have arrived. I will be using 640mm THK linear bearings(couldn't resist although they are costing £112 total!!! SHHH Don't tell the lady of the house) for the x axis and 25mm Rod and ali angle and vxb bearings for the y axis.

I am looking for ideas/suggestions for the z axis design, which I have 2 x THK rails 220mm long with approx 130mm travel. I want to keep the design within 150mm wide to maximise x axis travel. I also using DumpsterCNC antibacklash tightfit nuts throughout. (group) :cheers:

bigz1
06-02-2006, 06:16 PM
I have started construction of the z axis(just dry fit at present). I hope to make it slightly narrower to increase x travel, but will have to wait until the 780mm linear rails arrive to make sure a slim version will fit the carriages(Unexpected bonus they should have been 640 rails but seller couldn't find the carriages to match) . I estimate the cutting area to be 1200 x 650mm.

All pieces are made from Tufnol(borrowed from work). Machines nice but the dust is terrible.

I will eventually build 2 machines the larger one first using mostly linear bearings and twin thread on the y axis. A smaller version will also be made for sale using the spare 3 axis kit I have and skate bearings throughout.

bigz1
06-10-2006, 10:21 AM
Heres a pic of my WIP. Just slapped it together to see how it works. Z plate needs to be thicker .I need some countersunk bolts and waiting on ACME thread to arrive. Antibacklash nut is from DumpsterCNC.

I may put an additional 2 carriages on rails if the thicher z plate still exhibts deflection. Just trying to keep 6.5" of travel instead of 5" also their is a 7mm gap either end of the rails to increase travel(Just the bearing wiper overhangs rail and not the bearings).

In making this I have used only a bench mounted router, panel saw and a very cheap pillar drill. I was very suprised to see how accurate the holes drilled for the linear rails where(according to my analogue vernier calipers they where spot on parrallel). For the Y axis it think it maybe a good idea to fix the first bolt hole line up the rail and doting eack hole using a pointed rod thats the same size as the holes before drilling. then do the same with the other rail. just making sure the other ends parallel with the verniers before doting(although the holes in the rails allow some tolerence its not that much when your using a cheap pillar drill)

The x axis 780mm linear rails arrived(THK HSR25 carriages). I will use only 1 carriage to each rail which has allowed me to reduce the width of the Z axis assembly to 112mm.

HayTay
06-10-2006, 10:52 AM
whilst covered in an assortment of lucky charmsKinda kinky. I had a college roommate that had (and probably still does) fantasies that included a tub full of Lime JELLO. He had also dropped more than a little acid in his day. Do you think that maybe that had something to do with it?


Heres a pic of my WIP. Just slapped it together to see how it works. Z plate needs to be thicker .I need some countersunk bolts and waiting on ACME thread to arrive. Antibacklash nut is from DumpsterCNC.Your making great progress on your build. Keep up the good work and continue to post PICS.


Tested the circuit today. After the sparks stopped and the smoke disappered the meter showed 5.2V as per instructions. SUCCESS.Looky, there, now you can add soldering to your resume!


Is this a great hobby and learning experience, or what?,

HayTay

joecnc2006
06-10-2006, 01:32 PM
Looking very good so far.

bigz1
06-10-2006, 04:25 PM
Thanks guys. Your encouragement is much appreciated. :cheers:

My original buget is totally blown. I am upto approx £600(this also includes the spare 3 axis kit). My boss kindly put another £200 to the project, he will also supply all the MDF, paint. But I will have to put approx £80 of my own money to finish it(couldn't ask him a 3rd time)

Yep this is a great hobby. Starting to think how can I live without a 5 axis router!!! Hopefully the boss will comision a 8' x 4' machine so I can play at work too.

HayTay Jello = Jam in English(stuff you put on your toast)? Personally I would prefer custard with Kelly Brook, but hey each to their own.

bigz1
07-03-2006, 07:26 PM
Progress has turned glacial after the arrivial of a new family member last week(Harry - 8lbs 5oz).

:banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana:

Manged to assemble the router holder and beefed up the Z backplate. Z travel is now 4.5" due to play with only 2 carriages at 6.5"(play is approx .5mm when I press at full extension with all my meagre strength(this will probably improve once all the correct bolts are installed)). 3 hex bolts will eventually hold the the top of router and the holes in the sides are for removing the router bushes. Arbour lock and extraction have been modified from the mount that came with the router. Still waiting for my ACME threads from EMCO. The large THK carriage is 1 of 2 for the Y axis.

I will start the MDF X axis once I return to work.

bigz1
08-16-2006, 03:40 PM
Dry assembled the X axis at work. Progress is slow as I have only have 2 X 1/2 hour breaks each day to build it. Machine in photos is lying on its side and two large side plates still need to be cut, but should have them finished tommorrow. To give you an idea of scale the rod is 25mm X 1484mm. 2nd picture shows the top and the 2 grooves that will support the top rods. Rods will also be under tension when finally bolted.

The temporary torsion box is 100mmm thick the replacement will eventually be 150mm and will be cut by this machine. This one deflects by approx .75mm if I stand in the centre. Apparently by increasing the height by 25% the strength increases by a factor of 8. So from 100mm to 150mm increases the strength by ????? :confused:

bigz1
08-27-2006, 05:44 PM
Assembled the monster X axis at home today.

Learnt a few valuable lessons.

1. Its not a good idea to make the machine such a tight fit that you cant assemble in the shed.

2. Make sure its not going to rain when you assemble it.

3. Never ignore your own measurements or plan of action to get it in the shed(especially if its a tight fit.)

4. Make sure your help dosn't bugger off before it rains.

5. The missus is not ideal for holding on to the shed door for re-hanging in the rain.

6. If you want to kill yourself move monster machine on your own in shed(where no one can here you scream.)

7. If the machine is a failure it should make a great play pen(as demonstrated by dads little helper).

bigz1
08-27-2006, 06:23 PM
Looking through this site their are some fantastic machines in MDF that can rival the Aluminium ones for aesthetics. Their are also a few that would qualify for this catagory but unfortunately are let down by splits in the MDF.

Listed below are a few tips that I find useful in avoiding spilts in 18mm(3/4") MDF without using clamps.

1. Use 4 X 45mm(8 Guage x 1.75") Coarse thread screws.

2. I use slighty larger pilot hole (3mm (7/64")) than normally recommended 2.5mm(3/32").

3.Use a countersink bit(or better still a countersink with pilot drill as shown attached). Clearence hole not essential.

4. Screw a least 25mm from the end of the joint.

5. Always set the torque on cordless screwdriver to the minimum required to do the job.

6. For those occasions you measure twice and still drill in the wrong place. Car body filler(see attached for mistake by the bearing ). Its tough easy to sand, hardly any shrinkage and dries in 10 mins.

7. For Bolts use M6 x 45(single thickness MDF) and 60mm(double thickness MDF).

8. After drilling and tapping, line tapped hole with superglue. When dry re-tap.

9. Avoid Butt joints in your design and if possible and substitute with lap joints, dado joints etc.

10. An easy way to beef up a Butt joint is to first glue and srew it together. Then drill through both panels and insert some dowel rod. Cut dowel and sand flush to surface.

The 'Heath Robinson' device containing the drill, has been my most valuable tool, especially when drilling 2 bulky panels at the same time. Being a cheapskate, I converted the router holder that came with the laminate trimmer rather than buying 'Wolfcrafts' accessory for £20.

http://www.wolfcraft.com/product_detail.cfm?id=80

Hope this is of use. :D

Madclicker
08-27-2006, 09:50 PM
I use MDF flour saved from machining mixed with white or yellow glue to fix MDF fu's. Almost free (except for the glue) and ends up stronger than the MDF itself. It also makes a good thickener and extender for epoxy resin.

bigz1
09-09-2006, 04:08 PM
Testing out skate bearings for Y axis(Using bearings as spacers until I get something more suitable). So far so good.

bigz1
09-17-2006, 08:30 PM
Dry fitted Y axis today(minus gantry and half the bolts). A quick test of the bed relevealed a dip of .3mm in the centre. Also I clamped one end of the axis and tested for racking revealed movement of 1.2mm(I was pulling with all my meagre might) but this will improve dramatically once the twin ACME threads are installed. Bearings run smoothly with only a slight tensioning at the ends of travel. All 16 bearing rotate constantly througout the travel(Chuffed with how accurate the routing is for the seating of the rod to form closed skate bearings. Considering it was done with only a hand held router)

Hope to have the Z axis attached by end of week.

bigz1
09-22-2006, 08:33 PM
Found this metal file case at 'Partners the Stationers' for £10. Should be ideal to house my driver kit. Measures 300mm x 250 x 350mm.

Also finished Y axis today. yellow string shows location of X and Y axis ACME thread(still hasn't arrived in dispute with ENCO:argue: and have bought elsewhere).

Double checked the bed of the machine to see how flat it is now the X and Y axis are finally assembled. The bed has a max of 0.0140"(.3mm) dip and I sat on in the middle to see the deflection and got an incredible miniscule 0.0025"(0.06mm). I have decided to make the tempory torsion box permament. Painting the Z axis and motor mounts this weekend(Will paint the whole machine once I have a new shed, missus dosn't know about the new shed yet);)

bigz1
10-01-2006, 07:53 PM
Modified file box to house driver kit. Electronics still to be installed but dry fit fine.

bigz1
10-04-2006, 06:24 PM
My ACME thread arrived today :banana: (I have had no end of trouble getting some). Attached image shows the results of testing my rubber CRUD CATCHER(Trade mark).The rod was covered in oil and crud and you can see how much was wiped in just 12". Its very Heath Robinson at present but their will be 2 of these either side of the nut with a faceplate to hold it in place. Rubber is from a bicycle inner tube and used a hole punch for the hole. Cheap as chips and simple.

epineh
10-05-2006, 05:34 AM
Your machine is looking great, keep it going. Had to look up Heath Robinson lol.

Russell.

bigz1
10-16-2006, 07:02 PM
Poor quality video show results of driver test. Took about 20mins to set up MACH3 demo and to learn how to jog and slave the Y & A axis.

http://i107.photobucket.com/albums/m300/bigZ_04/th_DSCF4214.jpg (http://s107.photobucket.com/albums/m300/bigZ_04/?action=view&current=DSCF4214.flv)

:banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana:

Hats of to Dave at HobbyCNC for producing an excellent product. The Yahoo group was very helpful and I have learnt a great deal. I did mess up slightly towards the end and melted the DPST switch(cost £1.45 to replace locally and is illuminated). Also kept blowing the 4 Amp fuse because a component on the driver board was touching my metal case. These were both minor problems caused by my inexperience.

Most worrying part of the build over. Hope to install the ACME rod to 2 of the axis by the end of the week.

bigz1
10-17-2006, 07:49 PM
Poor Man's Lathe

I couldn't manage to slide the bearings on to the rod. So after sawing the threaded rod to the appropiate length. I pushed it through 2 pieces of MDF(3 pieces for long lengths) attached a dril at one end and filed the diameter down slightly and tested for fit. Also used it to turn flats each end using a grinding disc in a dremel.

bigz1
10-23-2006, 07:37 PM
Conected the Z axis and managed to get 130 Inches per minute travel under no load(Proberly end up at 90-100 IPM). Just sat for ages, grinnining like a fool watching it travel back and forth.

Problems installing the Z axis. Put holes for the attachment of Y axis anti-backlash nut behind the ACME thread on the Z axis. Will have to drill 2 more and offset them to one side. I could take the rod out and attach the nut, but it will be easier to adjust everything square later if I re-drill them. Apart from this everthing is looking good. The 2 black squares either side of the Z axis 2 antibaclash nuts for the slaved X axis(Just misses the Z axis at full travel.PHEW!!!). A pleasing unforseen result of this design is the cable for the motors,router limit switches can be routed through the top of Y axis and won't be dangling.

epineh
10-24-2006, 05:18 AM
Lookin good so far, know what you mean bout watching an axis move, something about a machine actually moving after sooooo much work.

Keep up the good work.

Russell.

bigz1
10-24-2006, 02:46 PM
Thanks Russel. I have been following your thread on making cable carrier. Great idea even started looking for prices on trunking only I found cheap boring black Cavotec stuff for £13 a meter.

Liam

Oldmanandhistoy
10-24-2006, 03:14 PM
Hi Bigz1,

Nice tread and design.

One small point; don’t see any cooling fan in your electronics enclosure?

Do you foresee any problems using this design when it comes to loading materials for cutting? I see how your design would work well were rigidity is concerned but after your finish the build it might cause some issues?

One last thing; shame your bearing rails run out side the box so to speak as it would have been a synch to cover to enclose the machine to sound and dust proof.

John

bigz1
10-24-2006, 04:10 PM
Hi Bigz1,

Nice tread and design.

One small point; don’t see any cooling fan in your electronics enclosure?

Do you foresee any problems using this design when it comes to loading materials for cutting? I see how your design would work well were rigidity is concerned but after your finish the build it might cause some issues?

One last thing; shame your bearing rails run out side the box so to speak as it would have been a synch to cover to enclose the machine to sound and dust proof.

John

Thanks John.

The fans under the switch in the centre of the box.

You make some valid points concerning the the loading of materials. I intend to open up the end of the machine once its moved to a new shed. I intend making a smaller version of this machine for sale(to get rid of a spare driver kit). This time the skate bearing will be on the sides and the lower side skirt will be below the bed. The side openings will be a lot bigger.

Yep I did consider putting the bearings on the inside and sound proofing it. Just thought I would get better ridgity with the skates compressing rather than pushing out. The Y axis steeper also doesn't help in covering it(perhaps rack and pinion?)

Funny how some of the most obvious design mistakes don't show up until your actually building it and then you get a heap more caused by the fix. :)

Liam

bigz1
10-25-2006, 02:34 PM
John gave some more thought to your suggestion concerning enclosing the machine and I think I have a solution. I will include it in the next build.:cheers:

Liam

Oldmanandhistoy
10-25-2006, 02:38 PM
John gave some more thought to your suggestion concerning enclosing the machine and I think I have a solution. I will include it in the next build.:cheers:

Liam

Your welcome, a brief description might be nice?:)

John

bigz1
10-25-2006, 03:20 PM
It will be very similar to this design(with the improvements as already mentioned). Except I will extend the 2 End panels. A roof will span across the 2 end panels with room for a light. 1 Lift up door a the back for any maintanence needed on the fixed skate bearings. Another lift up door at the front with a glazing panel. Am thinking a 3/4 door at the top and a lift down 1/4 door to reduce the height and the weight of the lift up door.

Sorry no pictures at present. Hope the decription helps. This time I will be using skates throughout(reduce cost + I have 4 meters of Ali Angle and 64 bearings left). I will use this machine to make it, but you could still use a panel saw/router to make it. If theirs intrest perhaps I will make a Solidworks model/PDF available?

Oldmanandhistoy
10-25-2006, 06:34 PM
Thanks bigz1 that makes things clear should work a treat.

As for the Solidworks model/PDF I for one would enjoy looking over your plans I find other peoples ideas not only educational but they can inspire new ideas of my own.

Please keep us/me posted when you start cutting parts would like to know how your design performs.

John

Oldmanandhistoy
10-25-2006, 06:54 PM
Just reading back through your thread and didn’t see a reply to your question about software (may have missed it).

I am using Turbocnc for control software from here http://www.dakeng.com/turbo.html excellent software and very easy to use. Did think I would up grade to Mach3 (no not the razors for the UK viewers ) but have not felt the need; used it now for two years.
I also use Sheetcam from http://www.sheetcam.com/ excellent cost effective and very easy to use also, for 2 1/2 d work.

John

bigz1
10-25-2006, 07:40 PM
Thanks John. I will have a look at SheetCAM. Using MACH3 demo at present.

Recieved 8 e stops today. Whats the best way to wire it to the HobbyCNC kit?:confused:

Oldmanandhistoy
10-25-2006, 08:06 PM
Bigz1 why you got 8 E stops:eek: . You only need one maybe two if you want one either end.

I’m guessing (please correct me if I’m wrong) you have confused E stops with limit/home switches?

John

Oldmanandhistoy
10-25-2006, 08:15 PM
Quick get out; I noticed you said it and not them. So guess you bought others for other machines (confused by seeing 8 switches in pic, well that my excuse and I is sticking to it also is late:tired: ) will shut up now.

John

Oldmanandhistoy
10-26-2006, 11:09 AM
Hi again,

I’m awake now (well never fully awake) :confused:

My E stop is not as yet wired up (chair) after over a year of running my machine. This is bad as there has been a couple of occasions it would have come in useful.

The reason being I can’t make my mind up whether to wire the switch to cut power to my spindle and drives or to my spindle and limit switches.

So would be interested in your/others opinions.(group)

BTW nice switches mine does not have a key:violin:

John

bigz1
10-26-2006, 04:06 PM
John

First. GET TO BED!!!!:nono: LOL. I had an excuse as am preparing to take Yorkshire Bank to court next week. So machines on hold for now. GRRRRR.

I have no idea on the wiring. So am looking for help(group) . I may also be getting a relay for the router.

The E stops where a bargain on E-bay(£18 inc P&P). Will use at least 2. Then theirs that 4 Axis Mill, Foam Cutter the all singing and dancing 6 axis router with bells and whistles etc. Can I attach them too the wife and kids?

Oldmanandhistoy
10-26-2006, 06:49 PM
Yorkshire bank I stopped dealing with them may years ago, best of luck to you.

As for wiring the E stop to the hobbycnc board. I have no idea as I bought a Xylotex board from www.simplycnc.com in the UK. Use drivers from Motion Control http://www.motioncontrolproducts.com/ now (excellent drivers IMHO) so can not help.

How are you planning to wire it, cut power to driver board as well as spindle, through limit switch and spindle or other? Cutting power to driver board on the dc side and power to spindle would be easiest imo.

You may need to ask the questions on this subject else where on the zone to get answers from the more knowledgeable types.

John

epineh
10-27-2006, 02:18 AM
Thanks Russel. I have been following your thread on making cable carrier. Great idea even started looking for prices on trunking only I found cheap boring black Cavotec stuff for £13 a meter.

Liam

Yeah, I decided my time was better spent on getting my machine up and running, then maybe using it to make the chain, if it works...

Russell.

Mike F
10-27-2006, 05:07 AM
Liam,

I know the problem of where to put the E stop, I'm at that stage myself and there does not seem to be any consensus of opinion. I have opted to put one on the mains input to cut power to everything and may consider a software stop too. What I would really like is to put one somewhere in the circuit so that all movement of all axes would stop, and the spindle, yet power remain to the drives so that the Z won't crash into the workpiece. Not sure this is possible though.

In my opinion, the real E stop should be on the mains side so it cuts power to absolutely everything should the unthinkable happen.

Good luck with the build,

Mike

epineh
10-27-2006, 07:16 AM
I think the theory behind the e-stop not cutting the power to the drives, is about halting the motion, eg a large heavy gantry moving rapidly, needs the servo's to stop it or it will tear itself another axis, so to speak.

My machine will be so slow that in the event of a runaway you will have time to make a cup of coffee, drink it and wash your cup before the power needs to be cut lol.

Hmm just re-read your post and that is pretty much what you just said, think I better get some sleep

Russell.

bigz1
10-28-2006, 03:23 PM
Russel am glad your going to carry on with your cable carrier experiments. I might have to still make mine as I think that Cavotec stuff wont be suitable for 1.2m of travel.

Regarding the E-stop am thinking I would like to stop both the spindle and the travel. Whether or not that means switching the power to the driver will require some reasearch on opinion.

Good news those Wunch of Bankers the Yorkshire Bank caved in before court case and have sent a bankers draft.

:banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana:

If anyone in the UK has ever had to pay a bank charge check out this site.

http://www.bankactiongroup.co.uk/

Its regarded as a penalty and therefore UNLAWFULL acording to British law. Banks are allowed to charge an adminstrative fee only(estimated at 50p rather than the usual £30-£80). You can can claim back as far as 7 years. I am going to spend it on extraction for this machine.

Oldmanandhistoy
10-28-2006, 04:10 PM
Hi Bigz1,

Good to hear you’re new.:cheers:

I would like to thank you for your questions regarding E stops; it has encouraged me to short mine which has been waiting for about a year(chair) .

How I have done mine right or wrong; I ran the spindles mains cable into my control box through a switch (to switch spindle on/off) then through my E stop. Also ran the dc side of my power supply through said E stop (kills power to drives not having a problem with the capacitor discharging and allowing some movement after hitting the E stop). Hope that makes sense?


John

epineh
10-30-2006, 07:22 AM
John, I assume you have the e-stop powering a relay of some sort with a couple sets of contacts, as you have both the dc power and mains power via the one switch ?

It is best not to have motor current flowing through you e-stop push button, use it to switch a relay or contactor, as e-stops are not usually rated for high current, and switching a heavy inductive load eg motors could possibly weld the contacts together, real bummer if you NEED it to stop.

I think you must have something like that as you are switching two different supplies ?

Russell.

Oldmanandhistoy
10-30-2006, 09:27 AM
Hi epineh,

The E stop is rated 4A and my spindle is 900w, no I am not using a relay.
Is this a bad thing to do. A simple yes or no will do as I would not want to hi jack this thread.

epineh
10-30-2006, 03:59 PM
Hmm well as far as yes or no goes, erm no.

Dunno what voltage you have over there, but if you use P=VI to calculate your current (and use 240V), 900/240=3.75

While it seems you are in the ball park, it is the switching part that caused the problem, you would be familiar with how a stick welder works, imagine that idea on a very small scale - the contacts of your switch, every time you use it there is a small spark across the contacts that damages the surface. This damage will vary acording to the amount of current being used and the type of load - resistive, capacitive or inductive. Now this damage may not ever affect things enough to be a problem, but it might. Ever notice a switch that switches on a bank of fluoro's might crackle a bit when you turn it off (of on), and usually it will be that switch that will fail first.

The worst part is that it can usually weld to one position.

If it was just the on/off switch for the router it wouldn't matter, but you want this thing to work.

Sorry for the long winded post, but I kept it as close to yes or no as I could...

Russell.

Oldmanandhistoy
10-30-2006, 04:08 PM
Thanks epineh.

I will look into it.

John

bigz1
10-31-2006, 07:36 PM
E-Stops are not as clear cut as I thought they would be. I will leave this till last.

I have bought a 3m curtain rail for £18 plus top conectors. My intention is to hang my wiring from inside the machine just above the dual X axis ACME threads on 2 lengths of curtain rail. Stepper motors one side Limits switches and router cable the other. All wire will be shielded and earthed at one end. Wires shouldn't be visable from outside of the machine and its even cheaper than the Cavotec cable carrier.

http://www.curtainsware.com/id21.html

Oldmanandhistoy
11-01-2006, 07:33 PM
E-Stops are not as clear cut as I thought they would be. I will leave this till last.

I have bought a 3m curtain rail for £18 plus top conectors. My intention is to hang my wiring from inside the machine just above the dual X axis ACME threads on 2 lengths of curtain rail. Stepper motors one side Limits switches and router cable the other. All wire will be shielded and earthed at one end. Wires shouldn't be visable from outside of the machine and its even cheaper than the Cavotec cable carrier.

http://www.curtainsware.com/id21.html

You can say that again. I have now purchased a break out board with relays and lots of other bells and whistles. So I can set up an E stop correctly (I hope). Just in case you were going to ask where from; I have a family member holidaying in the US so have bought one from other there and they are going to bring it back for me.

Interesting idea with the curtain rail; be sure to let us know how you go on with it.

John

epineh
11-02-2006, 06:48 AM
Sorry to confuse the e-stop issue, there is a thread somewhere soley about e-stops, might help to shed some light (or confuse you more ;) )

I think that different machines could have different setups, mine would simply halt if power was disconnected, I have found the esc key is pretty sweet(turbocnc) 'coz you can resume the program once the problem is cleared.

Give me a yell if you need help.

Russell.

bigz1
11-05-2006, 03:59 PM
Finally found time to install the X axis Acme Rods. Unfortunately they appear to be bent in the post.:(

:boxing: :mad: :boxing: :mad: :boxing: :mad: :boxing: :mad: :boxing: :mad: :boxing: :boxing: :mad: :boxing: :mad: :boxing: :mad: :boxing: :mad: :boxing: :mad: :boxing: :mad:

God bless the Royal Mail and the USPS.(flame2)

Oldmanandhistoy
11-05-2006, 05:12 PM
Hi Bigz1,

I have purchased trapezoidal shaft from a UK company on a couple of occasions now and both times they have been slightly bent. These came in a very solid cardboard tube which had no signs of damage so can only presume they were packed bent.

Using a spirit level and a vice I managed to get them almost spot on, well near enough for them not to whip during operation.

I should add also that I used 3 blocks of wood in the vice, 2 on one side and 1 on the other trapping the screw between.

John

bigz1
11-05-2006, 06:23 PM
These were more than slightly bent and the packaging had been damaged. I bought another batch before from EAenterprises(ebay also known as widgetmaster on CNCZONE) US and they were perfect. But thanks for the advice. I will buy some more from the above as the price is excellent.

Liam

Oldmanandhistoy
11-05-2006, 06:26 PM
Have a look here http://www.ondrives.com/products.asp?recnumber=274

Might be of use.

John

bigz1
11-06-2006, 08:20 PM
Thanks John that will be usefull for the next one(commited to 1/2" x 10 on this router). If I was to make this machine again I would use either 3/4" or 18mm at least on the X axis and 2 start x 10 for 200IPM as this seems ideal for the tooling and material I want to use.

While I wait on more rod. I am going to install the steeper motors and homing/limit switches. I intend to use the homing switch as a limit aswell. I was also thinking of only putting limit switches on the z axis as it seems tooling height is set from a block anyway? Appreciate some thoughts on this.(group)

Oldmanandhistoy
11-07-2006, 05:12 PM
Hi,

Just a word about larger lead screws; think of the screw as a fly wheel. As the diameter increases so does the weight; consequently more power would be needed to start and stop rotation. So a larger lead screw would need higher torque from the stepper motors, higher rated drives and a more ridged machine all for no gain in speed or power. So keeping the screw diameter as small as possible is the way to go imo. I know there is a website some where that has a calculation tool for lead screw diameter but can’t remember where.

The question concerning home/limit switches, I have home and limit switches on all axes’ (home switched act as limit switches also). You might be surprised on the power your set up has and hitting the limits of your machine may course serious damage especially on a MDF (or plywood) machines. My opinion is use home and limits on all axis but I know some people don’t use them, so I guess it’s a choice thing. I have used my cnc router almost every day now for over a year and in that time only once have I hit a limit switch. I say for the time it takes to fit them why risk more serious damage.
On my small machine I add code to the end of my gcode files to home all axes; this is to move the gantry out of the way so I can load the next job

Not sure how others set cutter height but here’s how I do it.

Lets say I am cutting counter sink holes in plywood; I set cutter height to top of material. I fit the cutter into my collet just tight enough to hold the cutter but am still able to slide it in and out of the collet. Push the cutter right into the collet, then jog the Z axis over the material; jog Z down to 0.3mm less than my tool length offset, then slide the cutter down to contact material surface. While tightening the collet the cutter will rise 0.3mm (obviously this will very with different collets) so when tightened the cutter will be set at exactly my tool length offset.

If I am cutting through the material (edge trimming or through holes and the like) I use the spoil board to set the cutter height. This is to be sure I cut right through the material even if it varies in thickness and don’t get the annoying feathers on my edges.

Hope this helps,

John

bigz1
11-09-2006, 07:54 PM
Cheers John extremely helpfull. I guess its just about balancing the speed of the machine with resolution/whipping/inertia etc etc when using threaded rod.

Liam:cheers:

bigz1
12-03-2006, 04:50 PM
Progress has ground to almost a standstill(work,work,work). Very frustrating.:tired:

Have managed to install replacement ACME rod and put in limit/homing switches. Homing switches also act as limit switches. All wiring is shielded and connected to earth in a star pattern. Couldn't find anyone who could sell shielded 2 core mains by the meter for the router.

I intend to buy a relay for the router so it can be turned off by Mach3 whilst travelling. Unfortunately my steppers arn't moving any longer.:confused: Hardware seems OK but will try connecting to a different computer as I have heard some programs can intefere with Mach3.

Oldmanandhistoy
12-08-2006, 09:52 PM
Unfortunately my steppers arn't moving any longer.:confused: Hardware seems OK but will try connecting to a different computer as I have heard some programs can intefere with Mach3.

Hi,

Do you have the problem solved?

John

bigz1
12-09-2006, 03:35 AM
Unfortunately not John. I am going to try using a different computer thi weekend. All voltage and current checks apear fine on the board and steppers lock up when turned on.

I have tried different versions of MACH but to no avail. Checked ports and pins numerous time plus motor tuning. DROs turn but steppers stay stationary.

Liam:drowning:

epineh
12-09-2006, 05:06 AM
Sounds like the signal's not getting to the drivers, if the motors are locking, the FET's are working, when I lost a FET (rest its silicone soul) the motor still locked a little and made a funny wirring sound but no movement, as you might expect. The fact that no motor's are going kinda leads away from bad connection's on the board, you might expect one motor to stop, not all.

Maybe try another lead, did you modify the parallel cable at all, I know I did more damage than good by that little excercise.

Otherwise it is looking like a fried parallel port, you can get cards to add more ports, pretty cheap, might be a fix.

Keep us posted.

Russell.

bigz1
12-09-2006, 06:06 AM
Thanks Russel. I have haven't modified the cable. But I have tried using a different one. Limit switches still work. Hopefully I get a positive result once I test on another computer.

Liam

Oldmanandhistoy
12-09-2006, 07:18 AM
Hi Liam,

Sorry to hear that; by the sound of it you have had the motors spinning?

If that is the case then it sounds to me to be a hard ware problem. Even if other programmes are interfering with Mach3 there should still be movement.

If you get stuck give us a shout here I am sure we can put our collective heads together and sort your problem.

Hope you have good luck in finding the fault quickly other wise you may end up like many of us here who have random bald patches where we have pulled our hair out.

John

Oldmanandhistoy
12-09-2006, 07:21 AM
Might be a daft thing to say but you know not all parallel cables have all their pins connected?

epineh
12-09-2006, 07:37 AM
Liam,

I'm not familiar with your drivers so please forgive me if this is a stupid question, at the start of your thread you had some small motors with driver cards attached, then you bought the hobbycnc kit and assembled it. Are the original cards you put on your thread a seperate driver kit ? If so can you plug them in temporarily to check if it is the PC or the hobbycnc kit ?

If I got it all wrong, it is late here while I am typing this, thats my excuse and I'm sticking to it...

Russell.

bigz1
12-11-2006, 04:37 PM
John, Russel. Many thanks for the suggestions. Tried driver kit on another computer and it works.

:banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana: :banana:

Major relief. So it looks like a blown printer port? I have an older computer but unfortunataly it wont run MACH3. So am looking to purchase another 2nd hand hardrive.

Perhaps now it will encourage me to finish the machine.

Liam

Oldmanandhistoy
12-11-2006, 07:18 PM
Hi Liam,

Good to hear you have movement again.
If the rest of the PC is ok you can buy a PCI card to replace your blown parallel port; cheaper than another PC.
Then again you could have a go with Turbocnc on the lower spec PC I have been using it for well over a year now and see no reason to switch to Mach software.
http://www.dakeng.com/turbo.html

Just an idea,

John

epineh
12-12-2006, 04:15 AM
Liam have a look around for a parallel port card, will probably cost next to nothing, as John mentioned far cheaper than a whole new(ish) system. It should "plug and play", kids have it so easy these days... when I was a lad, you had to do all that stuff by hand, took weeks... if your'e lucky...(keep inserting Monty Python quotes here)

Good to know you are going again.

Its kinda funny that you are relieved that it was the PC and not the CNC machine, whereas most "normal" people (as in non CNC folk) would freak out over a broken PC, I understand totally. We do tend to get attached to these contraptions...

Russell.

bigz1
12-18-2006, 05:09 PM
Cheers guys. I will probably buy a cheap tower no more than £60. I have several programs that require a better spec comp anyway and I don't want to put the good comp in the shed.

Just bought a solid state relay for the router to turn it on and off whlie travelling. I am thinking of putting the emergency stop on the router main(this side of e-stop is rated 600vac 10A) and the other side in series with the limit switches(I know its not ideal but its mainly to protect cutters/workpiece as I cant see any of my anatomy near the machine in action also the othe side of the e-stop is only rated at 240vac 3A). I wil also include a starter switch.

I am also 34 Russel, your making me feel old with the quote 'when I was a lad'. Looking at your thread it appears you have rediscoverd your childhood. Whereas I have never really grown up according to some.

Oldmanandhistoy
12-18-2006, 06:40 PM
I am thinking of putting the emergency stop on the router main(this side of e-stop is rated 600vac 10A) and the other side in series with the limit switches(I know its not ideal but its mainly to protect cutters/workpiece as I cant see any of my anatomy near the machine in action also the othe side of the e-stop is only rated at 240vac 3A).

:nono: You will get comments about that for sure; but what do I know. :D see my e-stop post.:eek:

John

epineh
12-19-2006, 04:28 AM
I am also 34 Russel, your making me feel old with the quote 'when I was a lad'. Looking at your thread it appears you have rediscoverd your childhood. Whereas I have never really grown up according to some.


While I chose not to grow up either, if I had access to the kind of hardware on discussion in this forum when I was a kid, my plans for world domination would be just about complete by now...either that or I would be less a finger or two.

As far as the e-stop goes, I am just about e-stop talked out, if that is a term, so no comment from me, so long as it gives you a bit of time to run from the (burning) building it has got my vote !!!

Russell.

bigz1
12-19-2006, 05:56 AM
Russel. I don't want to endanger myself(AM NOT THAT CHILDISH!!!!). I re-read what you said about Amps and contact on switches and I thought it sunk in?

Wouldn't the 600VAC 10amp side of the e-stop be suitable for my 240Vav 850watt router? The 3amp 240Vac side is to be connected to the DC supply from the pulled up pins on the driver board?

If not will leave the e-stop til the required funds became available for additional parts.

Cheers Liam

Oldmanandhistoy
12-19-2006, 06:19 AM
Would I be right in presuming you have read this thread http://www.cnczone.com/forums/showthread.php?t=17128 ?

John

epineh
12-19-2006, 08:27 AM
I just re-read my previous post, my e-stop comments sound pretty negative, wasn't meant to be...sorry bout that.

I would rather you put SOMETHING on for emergencies instead of nothing. For what it's worth on my setup I am going to connect the e-stop to the electronics/software and leave the router alone. My reasoning is that on my machine being a hobby type setup, there is no large gantry, no big spindle's, toolchanger etc, with an e-stop condition, it will just stop. This is also helpful as most e-stops (so far) are usually from me having a hold down clamp/screw in the way of the router bit, hehe. The software knows about the e-stop, and gives you the option of resuming the program so you don't ruin the part. You would be surprised how many times it gets used.

You may have worked out that I haven't actually connected the hardware e-stop yet, as I am planning on changing out my breakout board for another type, I am using the escape key on the keyboard for now, though it is never in the right spot to use.

I'm not sure about your e-stop, sounds like you have two sets of contacts? One with a higher voltage/current rating? Still probably not the best to switch router motor current.

Russell

bigz1
12-19-2006, 04:23 PM
Thanks for the thread John. Its sounds like its better to have the the E-stop through the driver board anyway. The only problem I can see with this setup is a computer malfuncttion or software problem?

Russel my e-stops do have 2 contacts.

Good news just won a computer on ebay should be OK for the shed.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ih=020&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=300060188996&rd=1&rd=1

I would also appreciate your thoughts on this. What do you think of running the extraction and router from the same relay?

I am working on splicing the remainding steppers tonight and making a start on wiring the socket connectors on my driver chassis. They are similar to din sockets but with locks and rated at 10A 100VAC.

bigz1
12-30-2006, 04:48 PM
Hooked up driver to new computer tonight. It works exccept I have installed conectors to the case and 1 of them is shorting. Test drived the X axis and it ran at the maximum of 100" per min without losing steps. Unfortunately one screw whips past 75"/min.

I also tested the router bit for movement in the X axisits approx 0.8mm(I was using quite a bit of force). I am little disapointed at this perhaps if I lowered the screw from it current position too the same level or slightly below the tool it would reduce the movement? Your thoughts and experience on this would be appreciated.

I am getting my finger out and hope to have the machine operational by Tuesday.

bigz1
01-06-2007, 05:55 PM
Using the routers power supply I intend to connect live wire to terminal 1 neutral direct could go to router (I have a socket in between so I can disconect my router from driver case and an earth connected which am using for earthing shielded cable). The live from terminal 2 will be connected to Emergency stop (rated at 600VAC 10Amps) and then connected to the router

To activate the Relay a wire will be connected from a pull up pin on the driver board to terminal 3 (positive) termianl 4(negative) wire is connected GND.

I have used the pull up pins to stop the machine via the e-stop using the other terminal rated at 240 VAC 3 Amps. The only disadvantage that I can see with this setup is a rare occurance of failling in the case of a software malfunction.

Any suggestions?

Trying to master the software side at present. Have yet to attach a pen and produce some drawings.

bigz1
05-02-2007, 07:11 PM
After taking a year to build a 3 axis CNC machine(should have taken 6mths). I finally cut my first piece. Finishing pass was a bit shallow. But not bad considering the tools are meant for steel and they were borrowed.

As soon as I have mastered the machine it will be cutting a 1:4 scale plane. Apart from the usual balsa bits it will cut a scale prop, hubs and moulds for tyres which will including the lettering. Speed of machine is 70" per min(although could ramp upto 140" per min just by changing the threaded rod). Rogh cut on leaf took 7mins and finishing pass took 10mins(leaf measures 120mm x 60mm)

Smile is from ear to ear.:D

Oldmanandhistoy
05-02-2007, 09:04 PM
Hooked up driver to new computer tonight. It works exccept I have installed conectors to the case and 1 of them is shorting. Test drived the X axis and it ran at the maximum of 100" per min without losing steps. Unfortunately one screw whips past 75"/min..

I have always found that no screw is straight and I have read somewhere that you should straighten a screw before machining and than again after. If you take the screw off and lay it on a meter long spirit level and turn it you will see the bend. What I do is hold the screw tight to the level at the high point and lift one end to straighten. Just go steady and with a bit of patience you will get it straight.


I also tested the router bit for movement in the X axisits approx 0.8mm(I was using quite a bit of force). I am little disapointed at this perhaps if I lowered the screw from it current position too the same level or slightly below the tool it would reduce the movement? Your thoughts and experience on this would be appreciated.

Don’t be down hearted about it until you do some cutting; you very likely put more force on it then it will ever see during normal cutting. If it is a problem you may have to reduce cutting speeds or depth of cuts.


Smile is from ear to ear.:D

It’s a good feeling making the first cuts and you soon forget all the headaches along the way. Nice job for a first cut; now the fun begins and you will be soon thinking about the next even bigger machine you intend to build. Now you have the machine to cut parts the next one will be a breeze. Don’t forget your build log :D

John

bigz1
05-03-2007, 05:44 PM
THX John. No plans as yet for a bigger machine. But would like to make another in Ali in the future with THK linear bearings throughout. Although am only getting 70" per min at present I could always upgrade to 2 start 1/10 on the X axis and top 120" per min. I am quite happy with the ACME but would use radial bearings for it next time.

The movement am getting is from the skate bearings and as you say it is not having an effect on the machining as yet. Glad I put 4 of them on I don't know how the guys using 2 get on. I have yet to really test accuracy/precision reapeatabilty but its looking quite good so far.

Using AutoCad and Solidworks for designs. Will be buying the complete Vectric Software for generating G code(So easy to learn mastered it in 1/2hr for each program) and have bought the liscence for Mach3 to control it(Still trying to master this).

http://www.vectric.com/WebSite/Vectric/cut3d/c3d_index.htm

In Mach3 I am having to put a scale of 0.0254 to get the 3d Gcode to come out the right size. Is this because I have put mm in the scale config for motors? Otherwise the machine tries to cut 80" rather than 80mm.

Latest test from the 3DCut demo.(dont no why the piece roughed out on the R/H side of the rooster? I don't think it missed steps.) MDF is not much good for this kind of small detail but its all I have to hand at present. Rooster measures 100mm x 80mm.

epineh
05-04-2007, 12:22 AM
For some reason I had been unsubscribed from this thread, and I missed the good bits !!! (chair)
Congrats on getting the first cuts happening Liam!!!

That smile is pretty hard to lose once your machine is going, I still have it even though my machine kinda died, don't worry it will make a comeback and be better and faster than it ever was :)

I think there is a new version of V-carve coming out that will do tracing, so no more using Inkscape to convert to vector, just import picture and create g-code :) ... maybe one or two more steps than that but it does sound good.

I use DeskCNC for creating toolpaths for 2D work, brackets, motor mounts etc, makes pocketing and contouring easy, the trial version is only limited to 1000 lines of code and you can do a lot with that.

If you try Desk, save your DXF's in R12 or R14 format (I think) and it will import them fine, I especially like the scaling, moving features, makes things nice and simple when converting from inches to mm.

Now go and cut like crazy and only stop to take photo's to post for us to see ! I will have to force myself to have a quiet ale for you, especially since it it Friday afternoon here now :cheers:

Russell.

bigz1
05-04-2007, 03:06 PM
:cheers: Cheers Russell. Its been a while since I updated this thread. Good to see some friendly faces again. Unfortunately I am going away for Bank holiday. So play is suspended but will certainly partake of the liquid refreshment. When I come back I will cut an aircraft propellor and hopefully be playing wth PhotoVcarve aswell.

I did download the Desk CNC demo but couldn't get it to work. So I guess I will try and master LazyCam untill funds become avaiable for VCarve.

bigz1
05-09-2007, 08:35 PM
Still to get rid of a few bugs. My limit,homing switches are interfering with the stepper motors at present plus I attached the z axis antibacklash nut with only 1 bolt after losing a tap in the other hole(Should have replaced but was getting impatient).

So far am working on a few samples for work. Attached used 6mm End Mill for Roughing(14mins) and 3mm Ball End for Finishing at 0.6mm pitch passes(37mins). Measures 150 x150 in Solid Oak. 3 deep lines on left hand side are the result of that missing bolt in Z Nut attachment. I intend to speed the machine to at least 140" per min as Revs on router are set at its slowest to avoid burning(router prefers to be run faster for optimim torque)

epineh
05-17-2007, 07:34 AM
How are your limit switches interfering with the steppers ?

Plus I think it is video time, just to make sure you didn't buy those pieces of timber at the local hardware store...:stickpoke

Russell.

bigz1
05-19-2007, 07:30 PM
The limits/homing switches had a dirty earth on the shielded cable(no longer earthed but works fine). Also the metal connectors where eathing the shielding to the metal driver case. Debounce is now set to 400 and not the previous 24000!!!!!.

I will post a video soon but have only just managed to config the homing switches and am trying to figure how to do the soft limits. Calibration checks need to be done. Also trying to figure out the best strategy for setting up fences for work piece positioning.

The wooden pieces have had no backlash compensation and came out reasonable accurate in size and tool start posistion was guessed. I only wish I could find MACH3 as easy as the Vetric Cam software.

Russel I meant to ask whats happened to your machine?

epineh
05-19-2007, 10:07 PM
Russel I meant to ask whats happened to your machine?

My router is, erm... hibernating at the moment, other commitments are taking all of my time. It needs a little TLC, I am thinking of either a complete retrofit with servo's and EMC or possibly scrapping it to make a new design, I just happen to have aquired a large ballscrew and two nuts, the screw is about 3.5 metres long and about 30mm dia and 1 TPI, I am thinking it would be perfect to base a large gantry router, with a 3.5metre by 1.5-2.0 metre x-y job size... decisions decisions.

I think I will keep the original router intact, I have to build a shed to house all of this stuff first, but before that have to finish building a house to live in. Soon as I finish all of that it's time for some serious CNC builds :D

Russell.

bigz1
05-27-2007, 04:20 PM
Bought Vectrics complete CAM package and finally cut something other than samples and test pieces. After knocking out complex 3D stuff and engraved lettering in minutes it took me 3 days to knock out this TREX!!!! Major pain was the 3.15mm cutter slipping out of 1/8" bush(had to wrap paper around bush to use it.NOT HAPPY) this ruined workpiece number 1. After that I had made the tabs to small and the extraction sucked up a piece and ruined workpiece/extraction/router bit.:violin:

After wreaking the above and righting off 2 endmills and blunting a 3rd. The smile on this little face was worth it.:) :banana: :banana:

Video to come soon.

Oldmanandhistoy
05-27-2007, 04:40 PM
Hi,

Is that you with the TREX?:D

Nice job.

John

bigz1
05-27-2007, 05:49 PM
Hi,

Is that you with the TREX?:D

Nice job.

John

Cheers John, but am a bit taller with less hair and teeth.:violin:

Found 4 X dual rail open linear bearings in our works scrap heap. Plus a neighboring factory is supplying some steel section. So will be making a small dedicated engraver(vaccumn table) with the spare 3 axis kit I have. Just require a few 1/2" internal bearings, ACME nuts, power supply and time.

Oldmanandhistoy
05-27-2007, 05:54 PM
I did say it would not be long till you are building your next machine. Serious addiction you have there. Don’t forget to do a project log:)

Are you planning to start making violins with your machine you sure like playing them? (wedge) lol

John

epineh
05-27-2007, 06:31 PM
Nice work Liam !! I was laughing at your "adventures" with making the T-Rex, I had very similiar things happen with my dino skeleton's, for a simple job they can be a little tricky - especially with a new machine :)

Those little pieces fly up the extractor chute at the speed of sound, while I didn't lose any cutting bits, in my first attempt I had the scaling wrong and the machine tried to cut pieces where there was no place to cut, didn't have the e-stop yet, and the machine did a fly cut of a steel screw, first (and last) bit of steel cutting I have tried with it...lol

First test runs are definately "interesting"

The kids love the skeletons though, I must get my machine going again and start mass production.

Russell.

bigz1
05-30-2007, 06:41 PM
Couldn't resist making another dino. The Raptor measures approx 2' x 3'. I used 6mm MDF offcuts from work. Unfortunately I dont think we have room for many more. Looking for something quick to make for the my 1 year old son now. Any ideas?(group)

On a more sombre not. I finally callibrated the machine. Under no load my axis's where all within 0.01mm after 50 rapid repeats as per MACH instructions. Borrowed some engineers guage blocks and set all axis's to at least 0.01mm. Router runout was 0.22mm. Cut several 100mm squares in all corners of the machine and managed to get within 0.01 on all side and diagonals. Router runout shows as a slight step in multiple passes(nothing I can't live with). Unfortunately drilling holes obviously means a 6mm hole is 6.22mm. But the biggest concern is when cutting circles I get a slight chatter in the same places even on small passes(10-11 o'clock and 4-5 o'clock). I think this is due to the X axis screw being to high relative to the end mill cutting posistion(approx 400mm difference).

Starting tommorrow I will start stripping down and modify the machine so the X screws are closer in line to the end mill. Hopefully this will stop the chatter.:idea:

joecnc2006
05-30-2007, 06:57 PM
I think i saw on the Shopbot forum a train engine that looked pretty cool.

Joe

bigz1
05-30-2007, 07:09 PM
I think i saw on the Shopbot forum a train engine that looked pretty cool.

Joe

Cheers Joe. I will look that up.

On your machine does the placement of X axis screw under the machine give much movement under load(thinking of doing something similar)? Does anyone else suffer from chatter on their machine?

bigz1
07-23-2007, 06:41 PM
Long time since last post as I was made redundant. I have since found a new job. Only just staring to use the machine again.

Dropped X axis screws and WOW what an improvement no chatter at all now. Cant believe how accurate the machine is. The most frustrating thing about CNC is it may take 10mins to cut something but it takes 6 x as long to draw and 2 x long to setup.:D

Russell will post that video soon promise.

Had to replace the plastic extraction mount after an unfortunate accident. Attached is the result uses neodymium magnets to attach in seconds(no fiddly bolts or nuts) and draught excluders came from a letter box in the B&Q bargain bin for £2.

epineh
07-28-2007, 03:05 AM
Had to replace the plastic extraction mount after an unfortunate accident.

Lol, thats sounds a bit like a Mafia hit, does it sleep with the fishes now ?

:D

Have I mentioned video ?

Cheers.

Russell.

Graham S
07-28-2007, 08:10 AM
A wonderfull read and an excellent machine. I started to feel increadibly inadequate over how well you handle the MDF and the excellent finish you have got, when I then noticed you are a cabinet maker I felt a little less bad, just. All my efforts with wood in general lead to terrible results, partly a lack of tools and partly a lack of woody education.

Graham

bigz1
07-29-2007, 05:23 PM
A wonderfull read and an excellent machine. I started to feel increadibly inadequate over how well you handle the MDF and the excellent finish you have got, when I then noticed you are a cabinet maker I felt a little less bad, just. All my efforts with wood in general lead to terrible results, partly a lack of tools and partly a lack of woody education.

Graham

Thanks Graham. The machine your making will more than compensate for the your lack in woody skills once finished. Looks great.

My weakness is the computer. Normally OK with packages but am struggling on how load the screens and asign keys for a zero plate?:confused: :confused:

http://www.cnczone.com/forums/showthread.php?t=36099&highlight=aussie

Russell I am cleaning the shed for the machines little screen debut. Good to see your servos working(way beyond me).

I think I will name the machine BigZ v1.

epineh
07-30-2007, 06:38 AM
Russell I am cleaning the shed for the machines little screen debut. Good to see your servos working(way beyond me).


Well working is a strong term, I just connected them to a battery, kinda cheating, but the drivers ARE coming :)

Russell.

bigz1
08-14-2007, 04:12 PM
Had a request from my sister for some Celtic medalions(She likes to shake a sword in the woods at the weekend). I was aiming at trying to produce something that looked more hand carved than machined. My sisters pleased with them.

Disc is approx 60mm diameter machine time was approx 2mins at 1750mm/min.

Managed to get Z plate working will post pics soon.

Sorry the video quality is poor but Russels been demanding proof.

http://s107.photobucket.com/albums/m300/bigZ_04/?action=view&current=DSCF4735.flv

Got the Celtic images here:-


http://www.onyxxpressions.com/celtic/CelticSymbols2.htm

Oldmanandhistoy
08-14-2007, 07:23 PM
Hi Bigz1,

Very nice job; what’s the material you’re cutting it in?

Time for the next bigger faster machine?:D

John

epineh
08-14-2007, 10:34 PM
Time for the next bigger faster machine?:D

John


I can see a definate pattern forming around here once a machine is built, on to the next one that is bigger better faster, more features etc.

I would elaborate further but I am busy drawing up plans for my next router...it is going to be bigger better faster and have more features :D

Russell.

epineh
08-14-2007, 10:39 PM
Oops, forgot to say nice vid, after nagging for so long :D I think I better acknowledge it, lol

So... when ARE you starting the next machine ?

Russell.

Oldmanandhistoy
08-14-2007, 11:32 PM
I can see a definate pattern forming around here once a machine is built, on to the next one that is bigger better faster, more features etc.

I would elaborate further but I am busy drawing up plans for my next router...it is going to be bigger better faster and have more features :D

Russell.

Why we can’t just build a bigger, better, faster and packed with lots of features machine in the first place I will never know. I think from now on I will advise absolute beginners to build at least an 8’ x 4’ machine as a starter and save them selves a lot of time and money. :p
Do you think me wanting a bigger machine is saying something about my manhood; bit like men with big cars?:o

John

epineh
08-15-2007, 06:37 AM
Do you think me wanting a bigger machine is saying something about my manhood; bit like men with big cars?:o

John
No, I think that only applies to vehicles :)

Why we can’t just build a bigger, better, faster and packed with lots of features machine in the first place I will never know. I think from now on I will advise absolute beginners to build at least an 8’ x 4’ machine as a starter and save them selves a lot of time and money. :p
John

You forgot to mention an auto tool changer, at least 5 axis with full commercial suite of g-code creation tools. Large brushless industrial servo systems goes without saying... all in the interest of saving money and time of course :D

Russell.

Oldmanandhistoy
08-15-2007, 06:21 PM
Looks to be a very interesting gizmo.

Congratulations on the forth coming occasion.:cheers:

I have always said if I were to emigrate it would probably be NZ; now I think most places would have to be better than the UK.:tired:

John

epineh
08-15-2007, 10:29 PM
Dont have time to make another machine as I will be getting married in 4 weeks and hopefully moving a bit nearer to you Russel in the New Year(NZ).


Congrats on getting married, I'm not too sure about moving to NZ though :D

Seriously though if you happen to decide to holiday in Aus once settled look me up, and I'm sure we can sip a quiet ale and discuss plans for the ultimate super hobby CNC router :)

We live in the pointy bit of Aus (just south of Cairns)

Cheers.

Russell.

bigz1
10-27-2007, 03:15 PM
Made this for my football mad younger brother in Perspex. Took only 10 mins. Although required 2 attempts as paint dosn't stick to Perspex without automative plastic primer.

Unfortunately the Z axis machine is starting to play up. Dosn't work or it soon quits.

bigz1
10-28-2007, 01:19 PM
The last one before the machine quit(looks like its either the stepper or hopefully a break in the wire).

bigz1
04-01-2008, 06:17 PM
My machines fixed. Stepper motor needed replacing.

I have added a Zero plate(couldn't imagine using the machine without it now).

Attached below is my camera mount and very first attempt at machining Aluminium with my machine. Very pleased with the results except I nicked the side machining the 2nd to last hole(just my luck its where its going to be seen). I used a conventional cut to machine but will try climb cutting in future. Webcam is for edge/corner/hole centre finding. Still have to add some buttons/DRO's to MACH3 to bring tool to offset position.

epineh
04-02-2008, 07:26 AM
Good to hear you are back in action !

Did you ever end up migrating to NZ ?

Russell.

bigz1
04-02-2008, 08:26 PM
Good to hear you are back in action !

Did you ever end up migrating to NZ ?

Russell.

Good to be back Russel. Been busy since last here as I was made redundant just before I got married. Best thing that could of happened as I am now in a better paid job and the redundancy is paying for the relocation.

It looks like I have a lot to read to get back upto speed on your thread.

As for NZ. As soon as my house finally sells things should motor along. Looks like I will be moving to Christchurch.

Cameras calibrated now but trying to modify some MACH3 buttons for the camera in Screen4 for the last 4 hours. But its freezing up and jumbling the screen around. Going to bed now otherwise am going to end up launching the computer.:D

Liam