CNC Plasma Cutter Recommendations?

[rfolea]

Any recommendations for a CNC plasma cutter for a high school classroom that would be useful for FRC type work?

And would you get a plasma cutter or water jet if you had a choice?

[Greg Woelki]

Originally Posted by rfolea

And would you get a plasma cutter or water jet if you had a choice?

A water jet is by far a superior machine, but is also far more expensive than a plasma cutter. Most teams who use water jet cutting (like my own) find a sponsor who will donate water jetting services instead of purchasing a machine themselves. OMAX and Flow are the big names in water jetting. A water jet can cut basically any material up to very high thicknesses and leaves higher quality edge finishes than a plasma cutter, as well as no slag, scorching, or warping due to heat. On the other hand, it's certainly worth noting that teams have used plasma cutting with great success.

When working with water jet cutting, it is advisable to undersize bearing bores and to ream them out afterwards, though one can get away with not doing so. One should also keep in mind the slight taper that the cut will produce if the machine doesn't have a 5-axis head to compensate.

[sanddrag]

We really like our PlasmaCAM system. It's a 4ftx4ft with a Hypertherm 65A plasma. It's been very easy to use and reliable over the time we've had it, and we use it a lot. It's just a really fast way to make things. It won't ever match the precision of a router or water jet, but you can go from idea to parts in minutes, and with the right material and settings, cut quality can be decent. You will get a little draft angle and a little notch at the lead in and lead out places. We usually do holes undersize and finish with a drill. We also got a drum sander and a tumbler to finish the parts and knock off slag stuck to them.

5052 aluminum cuts very nice. 6061-T6 warps like crazy when you have a lot of cuts and/or a large piece.

I absolutely recommend auto height control. You need that.

Our system came to around $20k with options including an extra software license.

If I did it again, I would absolutely look at a water table. Without it, the smoke is terrible. This is not a machine for a typical indoor space. You need a big industrial area with good ventilation. For us, we get out of the building when it is running and for several minutes after.

[sdcantrell56]

Neither.

A CNC router is a better machine for FRC than both of those. Since getting our CAMaster Stinger II SR-44, our 5'X10' CNC plasma cutter has laid dormant. The plasma cutter suffers from much worse tolerance and edge quality. It really is only useful for rough cutting. More of an artistic tool than an engineering tool.

[snoman]

We went with this company http://www.cncplasmacutterinc.com/
4x4 water table, dedicated plasma head, router,computer,and Delcam software for about 13k. Made our whole robot this year with the router out of 3/16 alu. Needs a good air compressor to operate plasma cutter. Machine accuracy was plenty good for what we needed and price point for a combo machine was the best we could find.

[Clayton Summerall]

Originally Posted by sdcantrell56

Neither.

A CNC router is a better machine for FRC than both of those. Since getting our CAMaster Stinger II SR-44, our 5'X10' CNC plasma cutter has laid dormant. The plasma cutter suffers from much worse tolerance and edge quality. It really is only useful for rough cutting. More of an artistic tool than an engineering tool.

We made our robot this year almost exclusively on a CNC plasma!
http://www.thebluealliance.com/team/4587