[Andrewcole]

Hi All,

This is my first post on the forum so please accept my apologies if this question has been asked before. I have built my own CNC plasma cutting table and have had great results with it using a cheap controller from China. I have been thinking of using Mach 3 for some time though as the controller for my machine as it seems to be more flexible and I can customise it, so I have decided to take up the challenge and learn something new

I would like to use Ethernet Smooth Stepper moving forward with BoB's, but before I commit, does anyone out there use their ESS with a torch height controller (THC) and if so, which THC are they using and to what success.

Also - how have you integrated your THC with your ESS, BoB's, Mach 3 etc...?

I've included a few picks of my machine build - hope the uploads work!

I appreciate any replies.

Thanks,
Andy

[Torchhead]

Unfortunately when you throw a THC into the mix with an external pulse card and MACH3 you hit a wall. Here is the issue. If you use the internal THC logic built into MACH it forms a "loop" where the Arc Volts are read by the THC hardware and the control signals (UP and DOWN) to move Z are sent back to MACH. With a parallel port in MACH the input signals from the THC are pretty fast so the loop is tight enough to handle moderate speeds. If you break the loop and insert a pulse card which now has a huge amount of latency (delay between when MACH thinks the axis is moving and when it really does ) It absolutely kills any real time control of the Z. The "loop" is not that great to begin with in that it does not have try PID (proportional) control and if you throw in several milliseconds of delay it becomes a random position generator! Even if you COULD use the external card you can't use the THC logic in MACH because it REQUIRES the Parallel Port driver and it won't share I/O with any external pulse card.

You might want to look at our MP3500-DTHCIV setup. It is a new DTHC IV that DOES work with MACH but does not use the internal THC logic. It runs at Ultra High Speed and can use Ethernet instead of the Parallel Port. It has PID (tunable response curves) and real time response is about 10X any MACH THC through a parallel port for motor control. With the addition of one cable it will plug directly into a G540. If you have a Hypertherm 45 or larger with the rear CPC connector the DTHC plugs directly to those with a single cable (MIC-01)

TOMcaudle
www.CandCNC.com

[wakedabed]

What is the THC you are using there?