Setting up a plasma cutter and looking for some help.

If you have decent latency, you can use Mesa THCAD wired directly to parallel port, i have one such machine in use.

People that have old TM systems that they want to keep running really value those old AVHCs. The smartmotor alone will fetch $350+ on ebay. The smartmotor it's self is a clever bit of kit and is still worth quite a bit, the rest of the lifter mechanics are a POS.

You are already using LinuxCNC to drive your table so you have access to all the axis velocity and acceleration information from your .ini file and by using halscope.

You are much better off (even though Tommy will disagree) to use one of the Mesa ethernet boards to provide galvanic isolation between the PC and the rest of your controls with a plasma cutter. An added side benefit is much relaxed latency and jitter tolerance because the FPGA does all the step timing. With the exception of Tommy most of the active PlasmaC users are using the THCad and either a 7i76E or 7i96 card for their machines, the majority of the actual cutting while testing PlasmaC was done using the 7i76E and THCad.

Get all your homing and limit switches working, while not an absolute requirement the functionality makes for a much easier (less dependent on operator skill and attention) machine to use when doing production use.

John

islander261 wrote: You are much better off (even though Tommy will disagree) to use one of the Mesa ethernet boards to provide galvanic isolation between the PC and the rest of your controls with a plasma cutter. An added side benefit is much relaxed latency and jitter tolerance because the FPGA does all the step timing. With the exception of Tommy most of the active PlasmaC users are using the THCad and either a 7i76E or 7i96 card for their machines, the majority of the actual cutting while testing PlasmaC was done using the 7i76E and THCad.

Um...not sure why you'd think that i will disagree about that, and i am glad i am an exception, should i also feel special ?
Jokes aside, i never recall being against the use of Mesa cards, especially since i have used and still have so many of them that it is hard to keep track where i put them, just on this table i have ...... leme count ... 7i92M, 7i74, 7i77 and 2x 7i84, plus a 6i25 with 7i77 and 7i73, i should have more in the shop as i should have another 6i25 and a 5i25 and a 7i73 there. And i used them in all the retrofits i did on industrial machines.
The only minor issue i have with some of you ( you know who you are, so i am just pointing fingers and not naming names here ), you are scaring the new users with all the possibilities, while it would be easier for them to start with a parallel port and as they grow they can better grasp the possibilities and the versatility of using Mesa or Pico boards. I am sure when they see their machines work for the first time they will be flying from joy, and since most of them already have a parallel port, why postpone that joy to them.
And i really appreciate the critique as i am fully aware that i still have to work on the way i write or express myself, some of the members here might still remember i was pretty bad at it and the second purpose of me being here on this forum was to get better at explaining stuff. That was triggered by the need to give back to this community as i will never forget the first moves my first DIY machine made under Linuxcnc, then EMC2. Since this has got to long, just to add this : that machine had some 250 parts in it, i must have made about 500 mistakes in it ! But it worked !
Thank you very much.

Im not getting scared off. I might ignore what people say but I am hard to scare.

Looking at my torch it gives 3 voltage outputs. Full voltage, 120V and 24V. As I understand I need to setup a voltage divider and use the 10V mesa card on the 24v output?

Any recommendations on a lifter setup? Not a real big fan of the one that come with the torchmate even before I started researching it. Too much play. I assume a stepper will be fine there as is does not need tons of torque.

Ok so looking more at the manual it seems I have a divided arc signal on the cnc connections as well that can be set from a 1:50 to a 1:16.7 ratio. Can I use this directly to the mesa board?


1drv.ms/b/s!Anw0aD8CF6Z_huIbtN0Cd2dSG7a9VA?e=HXL5aT is a pdf I scanned of the cnc connections. I'll let somebody more familiar with plasma figure out what would be best. If it matters the back of the machine lists 180v as the top end voltage.

That will do just fine wired directly to THCAD10. It also limits the maximum it can output there to 12V.
Also have a look at my youtube channel for ideas on floating heads.

www.youtube.com/channel/UCS0X88R7n7P2jIFwhIkw2Qw