Newby Plasma Table

Hello

I am new user with an interest in plasma cutting. I need to replace a Torchmate 3 (Flashcut 3) based table controller with something more reliable and robust. I will need a full featured torch height control built into my desired controller solution (I am done with closed stand alone THCs). So far I have not found a single full featured torch height control implementation here but I will keep looking. If I decide to go ahead and use a LinuxCNC based solution I hope I will be able to find others here to collaborate with or mentor me through the process. I am good with electrical/electronics, basic C and Python coding, use of CAD and Sheetcam for CAM, and the commercial operation of my plasma cutter for last 4 years. I have a poor grasp of programming GUIs and lower level OS integration. I am attaching a preliminary requirements document I prepared. I welcome any comments, questions or criticisms that anyone may have.

Ok, now for the inevitable newby questions:

1. Which real time extension offers the best option for future growth and base OS flexibility?
2. Can a Mesa 5i25/7i76 combo read a Mesa THCad output?
3. Is a Mesa 7i76E a substitue for the 5i25/7i76 combination?
4. Which GUI is preferred for ease of modification and extension? I will not be using a touch screen. This is an area that I really know next to nothing about and will have many questions.
5. What have I forgotten to ask about?

John

2. Can a Mesa 5i25/7i76 combo read a Mesa THCad output?

Yes, by using the encoder input

3. Is a Mesa 7i76E a substitue for the 5i25/7i76 combination?

Yes

I use a 5i25 7i76 with THCAD card from Mesa.

Same here, There should also be a demo configuration included with linuxcnc.
To get a feel for it, try sample configurations - by interface - mesa - plasma demo.

Works well with Sheetcam.

Rick G

Thank you everyone that replied.

I am going to try and see if I can get a LinuxCNC box working. I have the live install DVD and have tried it on two PCs, one must have a bad DVR drive because it intermittently will load and start the other loads and starts quickly. I want to eventually use a Mesa 7i76E card to make a working system. What is the maximum recommended jitter that will work with this card? The one PC I have available is an old Levono M58 and the jitter is up to 250,000 after an overnight run. Time to look for another old PC. I understand that the 7i76E card requires RT-Preempt as the real time system. Is there any reason not to go ahead and make this build under Debian Jesse? I want to use this to control a full featured plasma table. I have been reading through all the plasma related posts I can find on this forum and wiki as well as John T.'s installations and tutorials.

John

and the jitter is up to 250,000 after an overnight run

For your testing have you looked here for latency issues...
wiki.linuxcnc.org/cgi-bin/wiki.pl?TroubleShooting
Did you test with Wheezy? Did you also try 10.04? Old hardware may work better with 8.04 but that limits your upgrade path.

Rick G

Hello

I've taken the plunge and am underway with this project!

I have LMDE-2 setup on an old Dell Optiplex 745 following the instructions here:
forum.linuxcnc.org/forum/9-installing-li...debian-8-mint-lmde-2
I have upgrade the kernel to : 4.1.15-rt17mah following a miss mash of instructions. The latency isn't spectacular on this old hardware but I am told it is good enough for for the 7i76E under Preempt-RT.

I have a Mesa 7i76E card arriving from Mesaus tomorrow, a day late but not their fault. A big improvement on the 7 weeks it took to get my TCHad directly from Mesa. I also have a real Intel Pro 100 NIC from Ebay arriving for the real time Ethernet connection.

I am starting a new thread in the CNC Machines section to document this build.

John

The Post Office tracking lied! I received my card from Mesaus today on time!

John