Plasma cutter, automation project

[jimgerken]

Not exactly a tractor project, but I am hoping this will allow me to build better attachments. In fact, I put the snowblower on hold a few weeks ago, in anticipation of cranking out some cool parts for it with this NC plasma table. The attachment shows a closeup of the 9"x9" truck which will haul the torch handle across the metal (X axis). The truck rides on a gantry which moves fore and aft (for Y axis). The computer will also turn on and off the plasma cutter, so multiple sets of non-connected lines can be cut at once. For instance, think of a complicated shaped sideplate for the snowblower, with a 15" diameter shape blending to a flat, then angling upward and forward, turning down to a small radius, then backwards to the start of the 15 inch diameter again, then it needs a bearing thru-hole and three slotted bolt holes for the hangar right in the middle. All this from 3/16" flat in about a minute to 0.025" accuracy. Plus, both right and left identical. And the uses list keeps growing.

 

[Anonymous Poster]

Yep a very handy gadget. I used to work for a company that made comforter quilting machines. they had a 12'X12' flat bed with a precision jackscrew driven split sewing head on dual liniear bearings. A massive beast. we had to align them to within about .020 of perfect. I saw the potential for a cutting rig like you have. would just to have had to mount a plasma cutter instead of a sewing head. just feed the cad drawing into the pc and like magic it cuts the part. Expensive though those machines cost about 75K.

 

[Anonymous Poster]

try this site. http://www.plasmacam.com/

 

[jimgerken]

Yes, I saw that. A quick call revealed the price tag at $8900, without PC, without plasma cutter. Mine will complete for less than $400 plus labor, plus old PC, plus my plasma cutter. I will have about five weekends of time into it, I believe at this point. My software will be the big difference. Plasmacam's sounds quite advanced, with text and a lot of automation in the image preparation. Mine will be based on DANCAD3D and DANCAM/DANPLOT. I cannot say yet how fancy it will get with scanned images, etc. At least, the DANCAM will send a set of 2D lines created by DANCAD3D to the cutter and produce a part of the proper size. A few details: my system minimum step equals 0.006", max speed looks to be around 6 inches per second, which should suffice for the thinnest materials, working cutting area is designed at 4 feet square but could be expanded if desired,

 

[brantley]

Definitely post more pics as you make progress. I do not have a workshop built yet, but when that happens one of my dream projects is to build a CNC table for my plasma cutter.
I do have a few questions. What size steppers are you using? Are you building your own driver for the stepper or using something already built? What brand of plasma cutter do you have?

 

[jimgerken]

The steppers are 75 oz/inch NEMA 23 units. The driver is a Brewington tech Chopper 7026, 3 amps per motor per phase, and I am using a 32 volt input. The chopper driver keeps the current limited to a user-selected max while pumping the voltage way up for speed and torque. The motors are 6 volt inputs, 1.2 amps per phase. Plasma is the ThermoDynamics Cutmaster 38 with Itorch. I wish I had a machine torch for the NC table.

 

[Gfranklin]

I like it. I guess it's in gettin the rails dead parallel and then permitting some type of bearing bolt position adjustment? Is a machine torch a CNC mounted oxy/accetelyne torch? I saw one of these gas torches do the stainless steel mounts for my scoot's highway pegs. For days I envisioned all the things I could make with that. This is doing it again. Keep us posted and pictured.

Greg

 

[jimgerken]

Greg, a machine torch is a plasma torch built straight and without a trigger, intended to be used by a robotic arm. There is no trigger since there is no operator. The machine torches are compact and easy to adapt, compared to the big ergonomic operator torch I have.
Here is a recent photo, I'm about two weeks from cutting metal with it now.

 

[Anonymous Poster]

Interesting project!

Can't understand how I missed this thread previously...keep those updates and photos coming!

Bill in Pgh, PA

 

[jimgerken]

Here's a shot of the power transformer, driver card, one of the two cooling fans. I call this collection the "Power Chassis", and its all mounted on that black tray made of a couple pcs of angle iron and a strip of 1/8 by 6 flat iron. An aluminum enclosure goes over it all, with another fan in it.