Well, I really have no idea what I'm doing but after playing with an Arduino to make a rotary table controller, I got interested in steppers and seeing I had a basic plasma cutter here, I figured I'd have a go at building a CNC plasma cutter. I've decided to start with the electronics which I'm going to squeeze into a 40 amp plasma cutter case seeing I ended up with one that was beyond repair.
So after accumulating some stuff which includes a mini ITX pc and an 8 gb industrial SSD unit, and a 12 volt Xenarc 7"touch screen, this is the mess I have (ignore the Arduino)
Then I spent a fair bit of time designing some shelves for the enclosure to hold all the stuff
So from the top down. Existing breaker switch and terminal, 12v/5v power supply,
shelf for 48 v power supply
4 x DM348A stepper drivers, 2 x relays, 24 volt power supply
and room on the bottom for a breakout board behind the THC main board.
And this afternoon, it started to come to life
The THC controller interface box has a RS232 display on it and works in conjunction with the black knob to set voltages etc. there are heaps of connectors so I can't pass the wires through a grommet so have fed them out from under the panel. The THC is longer than the original slanted panel so I've extended the panel I made and folded it back to meet the case (you can see this detail on the rendered image). I did think about trying to mount it flush but in the end, I decided it was nice and easy to service this way even if the wires are a bit untidy.
The Black knob is part of the THC. Selecting a THC took me quite a while as with the way the AUD is these days, it was not viable to import stuff from the US. In the end, I purchased a stand alone Torch Height Controller from Robot 3T in Vietnam THC3T-03: Stand Alone Plasma Torch Height Controller .
You can find them on eBay but I bought direct and have been very pleased with the support received to date and the completeness of the kit which includes all the wiring, a voltage divider board and a proximity sensor for the surface sensing on the Z axis. Cost me USD $250 delivered. Not having a voltage divider or Arc OK signal in my Plasma was the deciding factor in selecting this unit over others, Plus Mesa were out of stock of their THC card. They emailed me the instruction book which is very complete and surprisingly well written.
For software, I am going to start with LinuxCNC and may end up with a Mesa board down the track but my PC has a Parallel port on the motherboard so I will give an ordinary breakout board a try first as I have one here. I am absolutely blown away by the quality of the LinuxCNC documentation and the installation was a breeze even though I don't know much about Linux. If I run into problems getting the THC going, I might try Mach3 as Mach3 config instructions were included. From what I read, I will get better performance from LinuxCNC.
Hopefully, tomorrow, I will be able to get the hardware off the design bench and folded up and the hardware installed in the case. I've got a small 24" pan brake here and have found it is pretty easy to print out a plan at 1:1 scale, glue it down with repositionable spray on glue and then it is simply a matter of cutting, drilling and folding along the dotted lines and peeling off the template later. In this case, I have had to join 2 A3 pages together. I had to bell out the shelves so they are wider at the bottom. I just hope those folds work out OK.
I am certain I will have heaps of questions along the way. I'm lucky enough to have a mate who lives in the same street who is well versed with CNC builds and he's been helping me out a bit but any advice from the forum will be much appreciated.