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BeanO
10-29-2003, 12:42 AM
OK...
I know it's a waste of time....but,

I would like to build a itsy bitsy tiny CNC engraver (2"x2" table).

I'm a CNC programmer, at a machine shop, I want to build this engraver for absolutely no good reason whatsoever. (my definition of a hobby). OK, I think it might be kinda cool...

At the shop, we have BobCam, and I have the freeware version of Kcam, which will control a stepper motor controller.

Kcam says that it can control a stepper motor controler from my printer port.

I also have three stepper motors (12 volt) VERY tiny, with 2"
long lead screws, (from old 5 1/4 floppy drives), 4 wires into each

What i still NEED is a cheap (hobby priced) 25$ to 125$ interface (??? STEPPER MOTOR CONTROLLER ???), and some hints as to how to hook it up...

PS... i'm not really an electronics person..but i kinda, sorta understand transistors and diodes...

Thanks for any help and hints.

NeoMoses
10-29-2003, 07:14 AM
unfortunately, I don't have much help for you along the lines of stepper motors/drivers. I'm just going to say that I don't think this is a waste of time. As long as you're learning from it, nothing's a waste of time. This would be a great way to start off building a first machine, 'cuz it won't bankrupt you. :)

I'm guessing you'll probably build this to accept a dremel or some other small engraving tool? My first thought, however, is that 2"x2" is going to be very small. When you say 2x2, I hope you mean travel, and not overall table size. My recommendation would be to go just slightly larger on your travel, perhaps 4x4 or so if you can. you'll be amazed at how much more you can fit in the machine, and you shouldn't have to worry much about stiffness with it being so small.

I'm just thinking about what you can do with a machine so small... It'd be a shame to throw it away if you decide it's too small and build a larger one. A 4x4 would be really handy for engraving small hand tools, plaques, jewelry, decorative nameplates, etc... I could think of hundreds of jobs that a little engraver that is 6x6 or smaller could do well, and would save the "big machines" enough time that lots of people would be interested. Just a thought, though.

NeoMiller
10-29-2003, 10:02 AM
Stepper motor controllers are not that difficult to build. If you want to build one yourself, I can help you there. But if you you want to buy one ready made, I am sure there are many avaialable. To control such a small stepper, the controller should not cost even that much.

BeanO
10-30-2003, 01:44 PM
Thanks for the input.

I might get another book on electronics, and try to build the thing with 'Radio Shack' parts.....

ecnels
11-15-2003, 08:06 AM
Check out http://www.stepper3.com/ or query on the web using the words "stepper drivers" or "stepper controllers". There are several around - some pretty cheap, that work off of a computer's parallel port.

Regards,

Ev

cbcnc
11-16-2003, 02:10 AM
Hi,

My wife wants me to mill some rubber stamps. But what comes to my mind when I think of a machine that small is micro milling. Things like jewelry and small camera parts and so on. You could use fine pitch leadscrews and go for resolution. I would try not to use a Dremel Tool though as the shaft has too much runout.

Chris

ESjaavik
04-03-2004, 07:52 AM
Here is what you should use:
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=3801894206

So far I've only used it handheld. But it's sooo nice. Hand milling aluminum is just like carving butter with a hot spoon! It runs quiet, more powerful than a Dremel, and no measurable runout. I tried, but I think I was measuring my indicator, not the spindle.

On eBay.de they go for Eur.400 - 800. The one at 800 was new in original box.

Einar

JOE65
04-03-2004, 08:37 AM
Go to your local big box pet store (petcetera) and ckeck out the automated dog tag engravers. You put your money in, tpye your text, and boom a tiny 3axis engraver gos to work. Really cool.

ESjaavik
04-03-2004, 08:49 AM
Here is what you should use:
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=3801894206

So far I've only used it handheld. But it's sooo nice. Hand milling aluminum is just like carving butter with a hot spoon! It runs quiet, more powerful than a Dremel, and no measurable runout. I tried, but I think I was measuring my indicator, not the spindle.

On eBay.de they go for Eur.400 - 800. The one at 800 was new in original box.

Einar

teilhardo
04-03-2004, 05:48 PM
A good controller :

www.xylotex.com

Sounds like a fun project, what size leadscrew are you thinking of using?

lancedulak
07-21-2004, 05:30 AM
These guys seem to think your made of money :P

A xylotex controller is WAY over the top for what yo uwant to do. Actually most of them are. You should check around hobby Robotics sites for the controlller or possibly steppers with builtin controllers. Or hobby RC car/plane sites. Ill bet money the leadscrews you have wont work (too much distance per turn).

Now you have me wanting to do your project :D A tiny 2 or 3" knee mill would be fantastic!

Graham S
08-16-2004, 02:56 PM
but is an investment for the next machine and not expensive

High Seas
08-16-2004, 03:13 PM
Beano - Have you seen this thread?
http://cnczone.com/forums/showthread.php?t=5036
I kinda wanna do the same thing with some salvaged bits I've accluminated. I'm still sleuthing the controller - but a place to start cheers - Jim

RotarySMP
08-17-2004, 06:01 AM
I would recommend you look at using TurboCNC under DOS rather than KellyCAM as the stepper controller. DOS is free of windows tendency to stop an look at it's own navel every so often causing motion problems like missing stepps.

The xylotex drivers would be great for this job.

Please post pictures as you build it.

Graham S
08-22-2004, 07:24 AM
I noticed these on ebay:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=42899&item=3834015669&rd=1

They seem a nice price and you get a pair of little rails and two carriages on each. For a lead screw use 6mm threaded rod. This will have a 1mm lead so with 200 step steppers and half stepping you have 0.0025mm resolution. Make your own nuts from delrin so they are fairly long and the back lash is minimal. Use normal 6mm ID bearings on each end of your screws as thrust bearings. I am told that a normal bearing will handle half it's radial load axially. For a machine this size it means it should work great. You can then use nuts to pretension the thread to remove any axial play. Use PVC tubing (windscreen washer tubing) to connect stepper motors to the threaded rod. If you use Nema23 motors you could probably machine ali with this set up.

I also second TurboCNC, I use it all the time.

Graham

rwwink
11-13-2004, 11:15 PM
A while back I ran across somebody who built a small CNC machine for his hobby. He used, as I remember, MDF for the frame and some heavy duty printer motors for the drive. Seems like he used part of a credit card machine to make the slide for the vertical axis. I think he was using it to cut wax or foam. I've searched for a link to the web site but can't find it.
R. Wink

vladdy
11-14-2004, 12:34 AM
A while back I put together a little MDF framed machine, just for curiosity more than anything else..used cheap controllers [about $15 each] from someplace like kits r us, or hobbykit, resistor current limiting, surplus motors out of old printers, and drawer slides instead of 'real' linear slides..

but it work.. if you want more info or pictures, let me know..
I think total hard cash out was maybe $75...

enjoy

WayneHill
11-14-2004, 12:46 AM
Digi-Key - Quality Electric Components, Superior Service.
www.digikey.com

Radio Shack does not carry the stock they use to for the hobbiest.

chuckknigh
11-14-2004, 01:05 AM
A while back I had purchased a cheap chinese compound vise, for the purposes of converting it to CNC. Capacity was roughly 4x6 inches, and it had crude, but servicable cast iron dovetailed ways with adjustable gibs.

I needed to replace the leadscrews with something of higher quality...even the roughest allthread I could find would be an upgrade. :-) OK, so chinese quality control is less than perfect...trust me, the price was right.

Might make a good "proof of concept" machine for someone trying to learn the ropes. And, if I ever get some usable spare time, I'll start on it again, myself. Need to find someplace to buy some large square tubing, though, to use for the motor mounts.

-- Chuck Knight

rwwink
11-14-2004, 08:04 AM
A while back I put together a little MDF framed machine, just for curiosity more than anything else..used cheap controllers [about $15 each] from someplace like kits r us, or hobbykit, resistor current limiting, surplus motors out of old printers, and drawer slides instead of 'real' linear slides..
but it work.. if you want more info or pictures, let me know..
I think total hard cash out was maybe $75...
enjoy

I'm interested in putting together a 8" x 14" x 2" travel system with enough capability to machine 1/4" aluminum. Intent is to make 12" travel left to right (X axis) with 8" front to back (Y axis). Controlled travel of the Z axis would be 2" with a 6" pre-travel for cutter removal.
Parts I've got in mind for the guts of the system are:
Slides would be Bishop-Wisecarver series SW UtiliTrack, size 1.
Drive screws would be Acme screws by Green Bay. Most likely to be 1/2"-10 thread from 4140 material. Provides less the .001" error per foot with a 32 RMS thread surface finish. Nuts would be bronze with 2, back to back with shims, per screw to provide preload
Thrust bearings would be Misumi 9mm combined roller bearing with thrust bearing. Screws would be supported and captured on both ends.
Bearings and screw nuts would be lubricated using a central point Lincoln system I already have.
Motors - I haven't determined what they are yet but I'm thinking that they should be in the 600-800 oz in area with appropriate sized controllers.
Spindle Im thinking that a good small router in the 1/2-3/4 HP range with something around 15-20,000 RPM. I want to run high speed, solid carbide ball nosed bits.
Frame would be a combination of 80/20 and MIC-6 tooling plate.
For software, I intend to use AutoCAD, SolidWork and MasterCAM.
Any comments on the basic plan?

ger21
11-14-2004, 09:16 AM
Any comments on the basic plan?

Have you seen Swede's mill at http://www.5bears.com ?

vladdy
11-14-2004, 09:57 PM
The basics sound pretty tight, and should give good serviceability with reasonable accuracy and a half decent product life span..
Lots of good controller lately on ebay, and the 5 phase seem to be going for next to nothing, there were some Micom controllers for less than 50 for a set of three, around 6a I think, and anoter fellow had matching 600oz hold motors for less than 20 each, no bids when I looked at them..

Most hobby / light small shop builders want bi or uni polar controllers / steppers, the better 5 phase stuff seems to getting very little action on ebay..just the choices are more limited from what I've seen


enjoy..

JavaDog
11-15-2004, 07:45 AM
What are the drawbacks of the 5-phase stuff?

ger21
11-15-2004, 09:49 AM
Expensive, unless you can find them on Ebay.

vladdy
11-16-2004, 12:33 AM
I backed out on these three Mycom five phase controllersat $36.00 [item 3852441603 on ebay] because I won some IMS controllers that I had bid on earlier.. there were a couple of other sellers that had matching 5 phase motors for not much more..
drawback is finding replacement spares as well [easily and cheaply], especially if you want identical units ..just in case..

RotarySMP
11-16-2004, 02:53 AM
Use ball screws. I used good quality metric ACME equivelent on my lathe, and am now converting to ball screw. If you preload bronze nuts, they wear faster and loose preload. You end up constantly asjusting them and still not acheiving consistant backlash.

You won't need 600-800 Ozin motors for what you are describing. You will need fast NEMA23 ~200 ozin motors. Something like the powermax ones maybe.

MHINK
11-17-2004, 01:24 AM
I just built a 3 axis controller using 3 ramsey stepper kits. Total price was $112.00.
I just fed the step and direction signals from the bd25 parallel port to the boards, and was able to drive a small bipolar stepper I bought from all electronics. Do goolge search for ramsey kits and all electronics. My whole home made cnc router cost about $200.00.
-Mhink

BeanO
03-03-2005, 06:05 AM
I decided to build my own stepper drivers, so I got some stuff from www.digikey.com ..capacitors,resistors,breadboard,controllerchip, and a 26oz/inch steppermotor...cost about 100$..and was delivered in less than 48hours..
yup, RadioShack sucks ass... you couldn't build a flashing LED from the stuff they have there.
Anyways... I ordered the wrong controllerchip....It wouldn't accept direction/pulse without ANOTHER microcontroller/Direction/pulse decoder...
I was able to haywire it together enough to make it go a step at a time either diretion... But I had to use Mcodes... >>>lots of them

I think i've found the perfect chip combination, its a ...297 and a 298 ...(see link)... and I can build them for pretty cheap...less than 20 bucks an axis. AND digikey has tecksheets that i can understand...(it helps when you're trying to put the stuff together)
http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=497&M=L297D

Oh... 26in/oz is barely enough to drive a 1/4 UNF(well greased/no load) leadscrew...

THANX, for all the help...

PS...just got a job at Standard Machine/Hamilton gear(It's a big company,/no personal projects) ... So I probably will not be able to make my little machine at my new company...sigh

Chris401
01-19-2006, 10:43 PM
You might try the stepperworld.com controllers. I think some of the low power boards are in your price range.

MHINK
01-19-2006, 11:17 PM
I have used controller kits, #158 and #179 from this source
http://www.kitsrus.com/
They are inexpensive and work well. Make sure the PCB and schematic are the same on the step and direction external pins, as the PCB trace varied from the diagram.
You can't buy the parts for what the kit costs.
-Mark

chronon1
01-19-2006, 11:25 PM
excellentt 1st project -- already enuf uses to justify it 6x6 or even 4x4 .. cheap , low torque steppers, cheap fine pitch rod ( like 5/16 " x 32 or something) - easy to hand work small amounts of material -- tons of accuracy not critical for learning project - probably the controller is the most expensive part.. unipolary is easier and cheaper than bipolar steppers -

engravers are dirt cheap at discount stores .. this is the all time winner for learning machine ---

BeanO
03-17-2006, 03:20 AM
Arrrggg!!!... Ok, I've done enough learning, I know the difference between unipolar and bipolar, servo and stepper, and I even have one motor hooked up and tuned to my laptop,(4 more, with control chips, ready to go), linear rails are on there way(Ebay), just missed a bid on some 6mm ballscrews(Very Nice, would have outbid him, but didn't get home in time), Gonna go nuts, If i don't make something move + cut in 3D, using Gcode.
Yup, I've kinda forgot about my 2"x2" travel, using floppy drive motors.
But, I've learned LOTS, thinking/trying to build it.
BTW, a Super Cheap and Easy controller is a single chip, no diodes/ transisters/ capacitors/ resisters, no Nothing needed !! - ONE CHIP! .. 2 Bucks!!, dir/step using parrallel port... (1.0 amps? up to 12 volts.. no chopper).. I forget who makes it, but #'s are:
UCN5804B (unc5804 are the important #'s)
^0042
D041554

I think i need to build a decent machine first, but I'd love to build the tiny machine i first thought of, 2 by 2 travel, maybe 1/2 on the Z, using EASY to find parts, A complete machine, fully Gcode capable, that u can pick up with two fingers... easy to build, easy to understand, a beginner project.

Chris.

Ps: Thanks RotorySMP!!, I love TurboCNC... It is way better than the fancy/Slow windows based programs!

MHINK
03-17-2006, 11:02 AM
BeanO
I found a kit using this chip, click here
http://mpja.com/productprint.asp?product=8409+KT
But couldn't find just the chip by itself.
There are other kits which are more capable available too. Try kitsrus.
-Mark

joecnc2006
03-17-2006, 12:02 PM
BeanO
I found a kit using this chip, click here
http://mpja.com/productprint.asp?product=8409+KT
But couldn't find just the chip by itself.
There are other kits which are more capable available too. Try kitsrus.
-Mark

only rated for motors below 1.25a

vladdy
03-17-2006, 06:35 PM
Beano,
where in sask are you located, might have something of interest for you..

thanks

BeanO
03-17-2006, 08:09 PM
I've been in Saskatoon for over a year, Anything is interesting now!...And I finally broke down and bought a little pisspot car that's exellent on gas... SUV is parked.

Ps I thought that "allegro" made the unc5804 chip... but their search engine says NO...Anyhow I bought 5 of them (and motors) off of Ebay... they are really easy to hook up!

txcowdog
03-18-2006, 12:42 AM
My big question in this project is... what is that on your cat's head?

BeanO
03-18-2006, 01:42 AM
idunno!! not my picture, not my cat(i don't like cats, im a dog person), just got the pic from a dating site(some chick), and copied it(it made me smile).

but it does look like a lime skin....???,,...
doesn't it?

yamingf
02-22-2009, 04:44 PM
you can try to build a laser engraver from a used and cheap CNC router, get a really old cnc router at less than $1000 and a laser controller and/glass tube to build your own laser. you can get a laser machine within $1800 in this way:)

xudeen
02-22-2009, 07:58 PM
Well, since this old thread has been resurrected, any progress on the itsy bitsy tiny CNC engraver? :D