I have 3 CNC mills and I was thinking of getting a plasma cutter and directing it with one of the CNCs I have to cut profiles. I plan on using an outrigger bracket to hold the plasma cutter next to the machine over a table for the steel plate.
Has anyone done this and also what plasmas torch system would you guys suggest for cutting 1.5 inch steel?
Check HERE (post #8) to see some pictures of cuts made with a machine in the above price range.
I'm not suggesting it is impossible to do, just that your machine cost & operating cost will be high to obtain square edges.
For gauge thickness material, to steel plate in the 1/2" range the much lower priced plasma machines using compressed air would likely be "good enough."
Also be aware that edge finish on plasma is dependant on feedrate. Thinner materal needs fairly higher feedrates than a lot of CNC mills can offer. Cutting anything thicker than 1/2" requires bigger plasma units. As stated side flair increases with the thickness and the lower cut currents. You have to look at 100A and larger units to cut 1" material. Oxy-fuel will cut 1" like butter.
Here is idea
There have been quite a few cnc mils adapted to the plasma cutting process over the years.....one of the best I have seen was with a fixed torch mount....and the outrigger held the workpiece and moved it around. By having a fixed torch like this the molten metal and fumes could be captured in a small bucket affixed under the torch that had water in it, as well as suction from a fume extractor.
As far as cut expectations....on 1-1/2" you can edge start and cut with a 100 Amp air plasma (cannot pierce this thickness) at very slow speeds....edge angularity will be good...there will be a lot of dross and an extreme hardening on the cut edge due to a nitride coating from the air plasma process (air has approx 80% nitrogen content).
If you want the best cut quality...a 400 Amp high definition class plasma cat pierce and cut 1-1/2"....with no dross, and high cut speeds (maybe 45 inches per minute) and virtually no edge hardening...and squareness within 1 degree or so. A ton of fumes and smoke will have to be taken care of.
100 Amp air plasma....$5,500.00. 400 Amp Hyperformance plasma ...$75,000.00. Difference in cut quality, cut speed and operating cost?....priceless!
W. A. Whitney has been producing a punch-plasma machine for over 25 years....these machines use up to 400 Amp plasma with a fixed torch mount and move the plate under the torch....also have multi-tool punch capability. Incredibly productive machines.
Check out the plasma punch video at this link: