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CNC Darren
09-22-2004, 01:29 PM
Hi All
First post here, tho I have been lurking for awhile. Well I have decided to build a version of Jgro's free plans that are on here. Thanks to Jgro, very nice set of plans, and free to boot!!! Only change I think i'll make is to go with 1/2-10 ACME threaded rod instead of the 1/4-20 as on the plans. Its main purpose will be to cut out parts for model airplanes and possably some 3d engravings if I ever get that far in CAd.

For the motors/driver i'm going to go with the 3 Axis unipolar chopper system from HobbyCNC , as i think this would be the quickest way to get it up and runnning.

I Have a spare Pentium3 550Mhz computer to run it.

sound like a good start?

Darren

jgro
09-22-2004, 02:18 PM
Sounds good to me ;) The only thing that I would probably do different if I were to do it again would be the table top. It will sag over time. I would get some pieces of 2x2 steel tubing and cut notches into the end plates to support them. Then use a piece of MDO (medium density overlay) plywood as the main table top and another piece of MDF as the cutting surface.

jgro

CNC Darren
09-22-2004, 03:30 PM
Sounds like a good idea to me, I had thought about making the table replaceable as a whloe. So I could have 2 tables, one for clamping down parts and the other as a vacum table. I had also though about for the non vacum table just running 1-1/4X1-1/4 aluminum angle lenghtwise under the table to strengthen it instead of the MDF framework in the drawings.

Darren

jgro
09-22-2004, 03:52 PM
According to a program we have at work called MDSolids, a 1-1/4 x 1-1/4 x .125 thick aluminum angle will deflect about .06 with 20 lbs on it. Steel with the same dimensions is about .02. 2x2x.125 wall will deflect about .002. Food for thought.

jgro

CNC Darren
09-22-2004, 03:54 PM
ahhh ok. guess we will go with steel then :)

Thanks!!

ger21
09-22-2004, 07:43 PM
Just a note. I've got some 1-1/4 x 1-1/4 x 1/4" aluminum angle. 6061-T6. It is many times stronger than the flimsy 1/8" stuff. Yet still just as easy to work with.