Re: [CAD_CAM_EDM_DRO] plasma setup-leadscrew vs. rack & pinion + software

Plasma cutting is not a very accurate process so don't waste your money on
ballscrews or acme leadscrews. They will be too low geared and will fill up
with plasma dust very quickly. My plasma uses 8x35mm HTD toothed belt which
is cheap and accurate enough for anything I want to do. If I was building
another cutter I would be tempted to use HTD belt as a rack - just cut the
belt and stick/rivet it to the machine.

My machine uses 400 oz/in steppers with G201 drives. The belt reduction
gives 0.022mm (about 0.8 thou) per microstep. I can get reliable rapids of
about 13 metres/min (500 ipm) with Mach1 at about10kHz.

I would recommend Master5 if you have got Win98 or Mach1 if you have
Win2K/XP. TurboCNC is a cheaper option but does not have constant velocity
contouring. CV contouring gives a better finish on angles and corners.

Les

> Hi, I'm in the process of building my first cnc plasma unit. I was
> hoping someone could answer 2 questions I have .-First the specs on the
> table:
> I'm basically constructing a plasma table big enough to handle 4'x8'
> sheet/plate (5'x10' overall?).
> I'll be using g201 gecko drives to microstep 2 ) 542oz/in bipolar nema
> 34 steppers(thanks dave@ camtronics)
> At this point I'm trying to decide ( based on economics) the best way to
> move the gantry, so my 1st question is- with this type of
> setup,(plasma), what would be a more effective/effecient power
> transfer-gear rack & maybe pulleys, or a lead screw,( acme precision
> lead screw perhaps?)
> I'm trying to get the best torque/speed ratio,(isn't everybody!) -And
> based on best option, can anyone give some sizes/pitch,ect
> .
> (Also I realize that to do a lead screw setup, ball screws would be a
> better option , but right now funds are limited,put it into the
> electronics& motors)
>
> 2nd question- I've seen alot of software options out there,any
> suggestions for plasma? I have 500mhz computer, win98se, TurboCad v7, &
> corel trace ( packaged with turbocad program for scanning images to
> vector files)-Any hints on cost effective ( for now) programs?
>