Some Newbie Plasma CNC Questions

[vacextar]

Hello. First post here. I've been looking into purchasing a CNC Plasma table for a couple of years now......and would have already owned a used PlasmaCam machine about a year ago had I not been outbid by about $5 on Ebay. I'm looking for something in the 4x4 size range....no smaller. I was looking into the PlasmaCam mostly because it looks to be a "ready-to-run" package and would be pretty quick to get started. I'm not looking to spend a month building my own and trying to figure out what I need to buy for materials/control/computer/software.

So for the first question for you experienced guys, who makes the best "plug-n-play" package that I could get up and running quickly, is reliable with good support and good availability of reasonable replacement parts? Can I assume that most/all of these systems are able to import dxf files?

I own a custom car business and I farm out a bunch of water-jet and laser cut parts for the cars I build. About 90% of the parts I have made are cut from .080" aluminum, and the have .080" wide slots cut in them to interlock with other .080" alum parts. This has been one issue that apparently is a problem with these machines, as when you try to do this using plasma, the slot ends up with a jagged edge and tons of dross......but, it also sounds like a typical kerf cut is about .076" wide, which would probably work fine with a small amount of filing to open the slot up from .076 to .080. But!....is there any way in any of the software for these machines to make it just cut that slot in one pass, then back straight out or shut off the plasma instead of trying to shift over a couple of thousanths to cut the other side of the slot?

Next question is cut/edge quality. How clean will the edges of .080" alum come out compared to water-jet? I don't expect it to compare with laser, but these are cosmetic parts I'm cutting and I don't want to spend hours cleaning up the edges on all of these parts.

Sorry for all of the newbie questions, but it looks like there are plenty of pros on here that have the knowledge I'm looking for. Thanks for any help or advice you can offer!

[jimcolt]

First....it is difficult to tell you what machine is the "best" machine....as this totally will depend on your usage of the machine, your expectations and your budget! PlasmaCam machines are good....but stay away from the older models (The 98Z and the DHC), if you are looking at used or new...stick with the model DHC-2 (4 x 4) or the Samson (5 x 10) as these machines have a superior torch height control system....which is necessary for any plasma cutter that is expected to cut with good quality as well as respectable consumable life.

In regards to .080" aluminum being cut with an air plasma on an entry level cnc machine......you can get very nice edge quality, however fine features such as slots will have a bit of corner rounding (the radius of the plasma arc itself) ....but should not be jagged. An air plasma will often leave a little bit of hairy dross on the edge in areas wher the torch cut speed slows down for cornering, etc. The Hypertherm Powermax systems have low powered consumables that can provide a kerf in the .030" width range.

I have done a fair amount of .080" through .187" aluminum on my PlasmaCamDHC2 machine with good results.... gauge aluminum needs accurate torch height, and good quality plasma, and a machine with good acceleration and cut speed capability to at least 250 inches per minute for best results. If you have a drawing of the types of parts (with dimensions) you need to cut...either post them of send a .dxf file to me...and I'll offer advise in regards to what will/will not work well.

jim Colt Hypertherm jim.colt@hypertherm.com

Originally Posted by vacextar Hello. First post here. I've been looking into purchasing a CNC Plasma table for a couple of years now......and would have already owned a used PlasmaCam machine about a year ago had I not been outbid by about $5 on Ebay. I'm looking for something in the 4x4 size range....no smaller. I was looking into the PlasmaCam mostly because it looks to be a "ready-to-run" package and would be pretty quick to get started. I'm not looking to spend a month building my own and trying to figure out what I need to buy for materials/control/computer/software. So for the first question for you experienced guys, who makes the best "plug-n-play" package that I could get up and running quickly, is reliable with good support and good availability of reasonable replacement parts? Can I assume that most/all of these systems are able to import dxf files? I own a custom car business and I farm out a bunch of water-jet and laser cut parts for the cars I build. About 90% of the parts I have made are cut from .080" aluminum, and the have .080" wide slots cut in them to interlock with other .080" alum parts. This has been one issue that apparently is a problem with these machines, as when you try to do this using plasma, the slot ends up with a jagged edge and tons of dross......but, it also sounds like a typical kerf cut is about .076" wide, which would probably work fine with a small amount of filing to open the slot up from .076 to .080. But!....is there any way in any of the software for these machines to make it just cut that slot in one pass, then back straight out or shut off the plasma instead of trying to shift over a couple of thousanths to cut the other side of the slot? Next question is cut/edge quality. How clean will the edges of .080" alum come out compared to water-jet? I don't expect it to compare with laser, but these are cosmetic parts I'm cutting and I don't want to spend hours cleaning up the edges on all of these parts. Sorry for all of the newbie questions, but it looks like there are plenty of pros on here that have the knowledge I'm looking for. Thanks for any help or advice you can offer!