cnc plasma table

[chiliuno]

i've been looking around at these home built kit cnc plasma tables since i learned that there were people out there building them. one that looks good to me is torchmate, but they are a little pricy. i don't think i should spend thousands of dollars to buy a kit that consists of parts that shouldn't cost more than hundreds to buy.
anyhow, here are my questions-
1) i think i need to have a three axis machine- as i see it, voltage based automatic height control is an important feature when dealing with material that typically isn't perfectly flat and/or warps with heat input like metal does. what is a good system (specific motor, software, etc..) to accomplish this? unless of course i'm wrong and i don't really need the controlled z, in which case why not?
2) for a 4x8 cutting area, which i think should be more than enough for me, rack and pinion seems to be the way to go. basically, i'm just going to make a scaled up big and sturdy version of the plasmacam machine. the plasmacam design looks good and the mechanical components operate smoothly. is this a good plan?
3) what's the best software out there, i mean stuff that really works the way it should with no headaches, to run a machine like the one i'm trying to build?
sorry about writing a book here, but i want to get all the details right the first time to avoid waste and agravation. thanks!

[coherent]

As far as software, you can't go wrong with Mach 2/3 as your machine driver for the money. For producing your gcode specifically for plasma, visit the Sheetcam forum here and on Yahoo (and the sheetcam website). You can download a copy and get a free trial registration. Again, for the price you can't beat it and it's specifically set up for plasma. It'll automatically add lead-in/outs etc and is very user friendly and easy to learn. Sheetcam will import dxfs, and others, so corel is a low cost alternative if you don't have autocad or another cad drawing program. Quite a few folks use the corel and sheetcam combo and produce some great stuff quickly and efficiently.
-Marc

[johnt]

I too looked at torchmate and all the others and could not justify spending nearly 10,000 dollars on a machine I intend to use as a hobby.
After reading about guys building their own I decided to give it a try.
So far, I am glad I did.
My table is about half way done, my motors , power supply and controllers are wired and I can make my motors turn using corel,sheetcam and mach2.
I am learning the software by using the demo versions and when I go live I will purchase the full versions of Sheetcam and Mach2.
At first, the whole process seems a little overwhelming (ok, a lot overwhelming) but little by little with the help of this forum and yahoo it seems to come together.
Good luck with your project.. my advise is just do it.
Let me know if you need any other info. I'm new to this myself but I can tell you what I've done so far.
John

[chiliuno]

do you have a voltage based height contol? if so, who's how much $, and how well does it work? i was looing at tracker's, that one looks like it's got a decent torch height control, but 2,000.00? no way.
tell me more about your system! pics would be great too.

[coherent]

I have a Campbells THC 300. I just got it recently so 'm still trying to work out a few bugs to make it work, but I don't think you can go wrong for the price. I bought Mach 1/2 years ago, so that made my decision even easier.
-Marc

[chiliuno]

coherent- i sent campbell's two emails about pricing, but got no response. perhaps i'm not getting the message out effectively, but anyhow; what was the price on the thc300? and do you have a phone number that i could call campbell at?
thanks!

[johnt]

I am going to use THC from BOB Campbell. But I'm not to that point in construction yet. I think I read a post saying he was out of town for a couple days... He will answer your email.
BTW, his THC works only with Mach2, so if you are going that route you can forget about any other controller. Thats how I based my decision.

[chiliuno]

ok, quick update- i got in touch with tom caudle and later the same day (today actually) bob campbell. both responded VERY quickly and are very helpful. once i get a list of what all i need and prices, i'm going to spend a few bucks. hopefully i'll have the major fab for the table done this weekend, the rack and pinion done by the following weekend, and the electronics that I'm getting from bob and tom in place the weekend after. when i get a more detailed parts list i'll post it.