View Full Version : CNC made out of JUNK less than $100 pictures..

11-12-2004, 05:05 PM
Getting a square cut on the tubing, take a piece of paper wrap it around the tubing and overwrap it perfectly, get a square mark for cutting.filing tubing
I used what I had laying around, old fence posts bought for Butches yard.. Slotted for slides to go into. OD 1.42

[This message has been edited by ibewgypsie (edited 11-12-2004).]

11-12-2004, 05:06 PM
Acme rod, square thread cut to 25 1/2" length on portaband-mounted saw.
End of rod cut down on lathe to 1/4" bearings
Spot-centered with Uni-bit then center drilled same size as motor shaft. (no bearing this end)
Aluminum carrier cut down on lathe to ID of tubing, center bored to .05 of nut, nut pressed into aluminum carrier.
Motor mounted on 1/4" aluminum plate, then cut around diameter of tubing (socket) to center tubing around motor shaft.

11-12-2004, 05:17 PM
1 hours worth of work today, phone won't quit ringing. Yes I signed up at www.donotcall.gov (http://www.donotcall.gov)
Theory, thinwall tubing slotted, carrier with nut pressed into it slides up and down tubing inside, motor centers lead screw one end, roller bearing mounted in plate centers other end, OUTER threaded rods will clamp ends together like a tie-rod pneumatic cylinder.
ACme threaded rod turned down 1/4 one end for bearing, center drilled other end for motor shaft, setscrew to be added to clamp screw to motor shaft.. A square keystock slider will be bolted to carrier that just fits slotted hole in tubing, this keeps the wiggle out..
THIS actuator is made for positioning of a pneumatic/hydraulic cylinder. NO real load will be carried. No real tolerance desired.
More tolerance could be had with spring loaded dual nuts, and spring loaded end carrier thrust bearing. THIS was done on the cheap with JUNK laying around.
Motors are SUperior 250oz inch motors running from TIP120 transistor type drive connected directly to the parallel port.
Tomorrow, other end plates drilled for bearings, center turned to center tubing. Square pattern drilled for outer tie rods.
MOUNTS? any conduit type straps can mount this.. Mineralacs, conduit two hole straps..

THIS would be a excellent robotics manipulator using air pressure cylinder follower.. or light duty positioning.. Don't take a 250oz motor lightly, it can shear fingers off..

G.A. Ewen
11-12-2004, 05:39 PM
Soooo.... there IS method to your madness. http://bbs.homeshopmachinist.net//biggrin.gif

Good pics, can't wait to see it fully assembled.

11-13-2004, 01:25 AM
There is always madness to his method, but I like the way he works. Will be watching and waiting...
David from jax

Have gun, will travel.

11-13-2004, 02:19 PM
Sorry guys...

I thought I would have a day to finish.. BUT.. My daughter is here and I get to spend time with her, Family wins over shop.

I have made similar linear acutators with square tubing and UHMW, two blocks with nut locked between them. You can cut uhmw with wood working tools. Never made a round one.

Be careful thou. It was before I had a mill. I used a router mounted under a table to trim the uhmw. It grabbed it and shot it across the room leaving my fingers stinging. I counted them afterwards.. THis was about six or seven years ago.

THIS TYPE system, turned upside down, mounted to a table could be the basis on a gantry machine. Simple to make but able to guide a cutting torch, plasma torch or ?? light duty sign vinyl cutting with razor swivel knife. It was accurrate within .002

I cleaned the rathole of a shop. SInce I got sick I have kinda let it go, the mill table is stained, the chuck on the lathe is stained. I get to do what I told someone else recently and rub it with love and steel wool/machine oil.
I got a new vac thou (bought at auction), a 4hp genie shop vac. It sounds like a jet engine but will suck up a 5/8" nut that whacks when it hits the drum. GOOD STUFF man.. I love it.. it is a keeper.

Too bad some of you good hearted guys don't live close by. We could have some fun. I feel so lucky to have a home shop.. I got it one bite at a time.. OR, if my son was more interested..
David Cofer, Of:
Tunnel Hill, North Georgia

[This message has been edited by ibewgypsie (edited 11-13-2004).]

11-13-2004, 02:45 PM
Cooool. Yeah. It'd be fun to sit around and BS.
I'm getting front end dimentions from a guy with a basket case harley for that project we talked about with you.

11-13-2004, 03:13 PM

What do you make of this? ThREE unipolar drives for about what one gecko bipolar.. NOT as good as a gecko for sure.. but.. 3 for one price.

Yeah, Sorry, I am still looking for them drawings.. My life is chaos..

Imagine this? the cnc punch press, you put a redhot bar of metal in holding tightly with tongs.. step on pedal bang bang bang till the dies come together to a setpoint.. whoo hoo, ain't we having fun now? Reproduction side rails for your project.. or rod axles bent to shape/castor... WHERE am I going to store all the tooling dies thou?

David Cofer, Of:
Tunnel Hill, North Georgia

11-13-2004, 08:40 PM
I used to hate posts this size when I was on dial-up, but this is the payoff for being forced onto broadband by the glitzmeisters. It's great to be able to see a cool (&cheap --most anybody can build cool with an unlimited budget) project step by step.

Keep up the updates when ya get a chance, David.

"...cnc punch press..." What's next, a CNC power hammer?


11-13-2004, 08:49 PM
Where is the sketch of what it will look like when finished David .
because , to me its impossible to tell what your making , by one or two pics of bits of it.
all the best.....mark

11-13-2004, 09:39 PM
Aboard, imagine a hydraulic cylinder w/ the 4 tie rods.. now imagine a piece of pipe w.two square ends.. One with motor, one without..
Square key rides down slot in tubing carrying a switch plate.. a finger on the ram makes/ breaks the switches making the ram follow the stepper.. I'm sorry.. I'll have it together MOnday for sure.. I had it fabbed up this morning.. Not sure how much friction the key will see in that slot.. NOW in back-paddle thought the square ways in the square tubing made the friction equal on the slide.. not all on one side..

I am trying to figure out how to thread more rod.. perhaps someone else can help me.. I tried a few weeks back.. it deflected rod away from cutter about a foot out.. It'll take a threading die or a two sided threading tool opposing sides.. ???

I bought that six feet of acme rod.. killed the spiders on it and cut it up..


11-14-2004, 10:10 AM
A note on the above listed drives.. instead of them taking a broad range of power, Like a gecko or Rutex, they must have a linear power supply limiting the voltage.

THIS raises the bar on the price of the cnc system using them..

The system I have cobbled together used tip120 transistors and wave type control. (4 bit) I have schematics somewhere. instead of a chopper you use resistors to limit power through the motor coils.

SO, I have a linear supply to use on one small motor w/this drive but.. Geckos stepper and servo are better.. and they are on sale right now too.. $99 each.. If you have thought about buying some with a deal like that.. I'd run one on my indexer 24vdc but, I am soo stubborn.
I never got to try out a gecko servo drive..

THE used geckos I ebayed, brought $115 each..

David Cofer, Of:
Tunnel Hill, North Georgia

[This message has been edited by ibewgypsie (edited 11-14-2004).]

11-15-2004, 02:08 PM
First drilling the other endplate, center drilled 5/8" to match bearing I got free..
Pressed bearing in with arbor press You could do the same with a nut and bolt and washers.
Linear acuator fabbed up, nut in slide, acme screw in place, outer threaded rods in place
Two things left to do, one is thread the tension rods on the ends, two nut it, assemble loosely, insert flat key to ride in slot and drill-tap to traveler, nut on the acme rod..

Not going to get finished today, My 1/4 threading die is missing, not got a fine enough point to lathe thread..

IS THIS THE ONLY WAY? nope, as a matter of fact I like the square tubing better.. Fitted end caps, UHMW cut with a wood saw. More rigid, easier to fit up.

Drives are existing old MAXNC unit with 3900 nand gates tied together to invert port logic to TIP120 transistors. I have schematics if anyone wants them.. USE the wave type drive in Turbocnc.. it is a 4 bit per motor logic that addresses each winding in the motor seperately.

THERE is as many ways to make a cnc as there is to skin a cat, my first system was more basic than this.

CONSIDER, Acme rod 10:1 threads (I think?), stepper 200 steps per revolution = 2000 pulses per inch or .0005 resolution. NOW Repeatability comes from exacting tolerance in nuts, slides and ways. OR fitup..

I learned from a old guy that you leave everything looose, run the traveler back and forth while on that end, gradually tighten up the securing nuts/bolts. That way everything has a set to it's own fitup on that end. Nothing is in a bind like that.

What am I going to use this for? well I got two cherry type switches, put a lever on the follower on the hydraulic cylinder on my press. As the acme rod carries switches up/dn the solonoid turns on/off till it positions the follower onto the switches..

IN other words, this lil bitty motor will move 50 tons of press cylinder up and down.
Before you tell me all about safety I have estops on the front of the machine, a pressure pad, and a cable.. I still worry about hydraulic leaks.. injection under the skin kills the flesh..

I got a slip roll to finish today, I hope.. I got it mounted, 3/4 dc motor/30:1 gearbox direct drive to rolls mounted on a special sewing adjustable height table *(purpose to be explained for later).. Top roll is odd shafting that won't go into my steadyrest.. all is chain connected together.. My bead roller goes on the other end of shafting.. Foot pedals to be connected.. NOW since my brother got his arm in a wringer washing machine when we were young, that thing scares me.. that much hp could pull you though and mash you flat, but at least I'd be curved? HA.. http://bbs.homeshopmachinist.net//biggrin.gif

I'm still waiting on that "big black chicken snake" to come out of the 54 ford mainline.. it smells like snake, butch runs around sniffing and growling. I keep hoping to see it sunning itself since it was cold last night. Since he had a lump, he won't be hunting again maybe for months.. I warned the neighbor about thier small poodle chained up close by..

David Cofer, Of:
Tunnel Hill, North Georgia

11-15-2004, 02:30 PM

Check out this lil bitty tattoo..

Ed Hardy designs modified.. Tattooing by yours truly..
Back dragon is uprising, drawed on 7x11 sheet of paper, front dragon is downward going on another 7x11. center is about 8 inches wide..

NOW that old boy has a big arm.. Nothing done to the inside of his arm yet.. thou he has plans.. It's looking like another magazine piece..