Mesa 7C81 Questions

Hi there,

Just wondering how you are making out with your build? I'm looking into a plasma cnc and have settled on (I think) a Rpi 4 and a 7C81 Mesa but there isn't a lot of setup info out there on how to get it all done correctly.

Hi there,

Would love to hear how things are going for you. I'm looking to do a plasma CNC and have settled on the rpi4 and mesa 7c81 but am struggling to find information on a proper setup.

Do you intend to use a THC?

Yes I am, the plasma cutter I am looking at is this one (link below) and it supports THC.

I did a bunch of research on them and I watched a guy review one on Youtube and this looks like the best bang for my buck.  I've used a handheld plasma a while ago, but this is my first foray into CNC and I'm not looking to spend a tonne of money.

It's going SLOW! The trouble is that I have too many interests and projects and there aren't enough hours in a day. I've been spending time lately on a Triumph Spitfire I'm restoring.

Anyway, I had decided I just didn't like having the FPGA pins on the 7C81 connected directly to the servos and parts of the mill circuit board. So I designed an interface board to buffer the signals and do 3v-5v translation. I did it in KiCAD and had the circuit board made by OSH Park. Really liked the software and OSH Park. I never used KiCAD before and it was very easy to learn and use. Hadn't made a circuit board in many years, and the ones back then were pretty simple and crude. Stuff now is slick. I opted to go with mostly surface mount parts to get a lot of signal buffers in a small area. soldering those by hand (iron and hot air gun) was a might tedious. Minimum board order was 3, and so I've built all 3 boards. I'm currently in the process of testing every line with a meter, and will then power them up and test them. A lot of work, but I enjoy it.