This is the new version of my plasmacutter.
The mechanics is the same as before. You can see them in another thread with chinese HF-start plasmacutter. That was the previous version. Stepmotors running X, Y and Z with chain drive.
There is a waterbed for catching dust. The water level is a few mm above plate to be cut. It keeps even 1mm sheet totally without heat warping and thick plate cool to touch after cutting. The water is only about 6cm below the plate to be cut, that is enough to stop the plasma stream. I have added some citric acid to water to prevent rusting. The water container is made from stainless steel and coated inside with polymer to prevent galvanic corrosion of stainless steel.
At the top of the enclosure is a modified (cut the bottom open and connected to enclosure top hole) industrial vacuum cleaner that is sucking air from the enclosure through filters. It practically eliminates dust escaping the cutter. The enclosure has polycarbonate walls and door so it catches also splashes of water and sparks.
The plasma cutter is Everlast Powerplasma 60. The torch is a heavily modified WSD-60P from ebay. I actually sawed off most of the plastic handle etc. so I could mount it to Z axle conveniently, and bent the copper air tube of the torch. I also run separately pressurized air, plasma current and pilot arc. The connection to plasma cutter is a euro connector that has all in one connector. The plasma cutter is mounted under the waterbed.
The electronics is in electronics enclosure mounted under waterbed. Next to electronics cabinet is PC. All the signals are either optoisolated or relay-isolated. For the plasma cutter there is 3phase 400V 16A supply with RFI filtering. There is separate filters for PC and TFT display. PC works ok with PS/2 connected mouse and keyboard. For some reason USB mouse/keyboard sometimes caused problems (had to unplug and plug again), so I replaced with the PS2 connected ones. PS2 has much lower data speed so I think it is more noise immune than USB.
I think the use of a vented cabinet around the plasma cutting is a novel innovation. I have not seen it anywhere else. I am now plasmacutting inside my shop next to lathe and mill. Also the placement of keyboard, mouse and display on top of the enclosure is a novel innovation, making the floor space required minimal. The device is on wheels so I can move it.
(C) KU 2013
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