CNC Plasma Torch Construction

E. C. Marsh
P.O. Box 342
Saint Ansgar, IA 50472

4'x8' CNC Plasma Torch Construction Log.

A 5'x10' working table would of been ideal but my little garage doesn't allow me the room so I am going with a 4'x8' machine. The shop where the CNC will run is about 50 miles away and it would not be practical for me to continue driving back and forth for the construction.

On this project I plan on doing a better job of record keeping and drawing than on the first machine.

	May 1st. 2009, Where do I start? Searching the internet, cnczone, and eBay for ideas and some starter parts.
	I purchased a set of bearings to give a try. Looked like a good idea and the price is much better than the standard rails. They are sold by CNC Router Parts You use a section of 1/4" cold rolled steel for the rail.
	This is a test of the bearings on the steel rail. They are actually to be connected with 8020 1530 t-slot. I am using a piece of UHMW just to see how they work. They seem to be very smooth.
	When drilling holes, what works the best for me is draw the hole pattern in cad, print and cut the paper out. Then I use a glue stick to glue the pattern onto the piece. My wife is center punching the holes for the section that connects the above linear bearings together. Her hands are much steadier than mine.
	I drilled, taped, and bolted on the little 10" linear rail for the Z. The holes lined up perfect.
	Gluing more patterns to the aluminum for drilling the torch holder. My CAD program is Intellicad 4. It is a very good clone of AutoCAD 2004 and I have used it from 2003. It was around $300 and is pretty much identical to AutoCAD. I use it for everything and have never had a need to pay for an upgrade.
	The Z axes with the torch holder, motor mount, linear bearing and t-slot is bolted to the steel bearing rails. I really think I am going to like these bearings. The package came out very good. I have to get a motor and belt drive setup and this will be ready to go. The gantry is a 66" piece of 3"x3" t-slot extrusion.
	Here is the CNC unit laid out on saw horses. This is how I ma going to put the machine together. When completed and tuned in, we will take it to Meyerhofer's shop and he will fabricate the base for it.
	Although I purchased enough ball bearing setups for the X and Y axes, there was an auction on eBay for a pair of 45" and a pair of 41" THK linear bearings and rails. I put in a bid on them and was pleasantly surprised to get all 4 for quite a good price. They bolted perfectly to 1530 t-slot extrusion and will just about complete a 8' travel.
	I had to butt the THK rails together and figured if it wasn't going to work I should have no trouble eBaying back the linear rails and even making a little profit. The bearings run smooth over the joints and I do not see that there is going to be any problems with this setup.
	For the X and Y I purchased 2 Tormach 640 oz/in steppers off eBay. I am using Gecko G201 drives. For the Z, I bought a 269 oz/in stepper from Xylotex and a SideStep driver from Probotix. Hindsight, I would of just purchased a Xylotex 3 axes package and been done with it.
	Starting to layout the electronics placement. This is a stripped out Micro ATX case and I made a plate to bolt in for holding all the stuff. A 24 VDC and 5 VDC Chinese power supplies. A couple of Gecko drives for the X and Y. I mounted the Geckos on a hard drive heat sink. Not quite sure what to use for the Z yet. My first motor and drive wouldn't crank a bubble gum machine. Probably should just cough up the money for another Tarmac and Gecko.