Ohmic3 hal file errors

Also going through this I thought I read someone with a Hyperterm had issues with the ohmic torch?

I can't seem to find it now. He used regular and it worked. Something about the housing being grounded.

In the plasmac manual it states:
"Ohmic sensing only be implemented where the torch has a shield that is isolated from the torch tip that conveys the cutting arc."

The ohmic wire (torch shield) has a direct short to the tip. Could this be the problem?

On another note if I disconnect one of the encoder wires from the thcad-10, then the encoder velocity starts counting numbers.
As soon as I plug it back in the encoder velocity goes to 0 and doesnt move.

tommylight wrote:

bevins wrote:

The ohmic wire (torch shield) has a direct short to the tip. Could this be the problem?

In the torch there are an electrode, a nozzle and in SOME cases a shield. The nozzle is not a shield so it should not be used for ohmic probing as it may result in some interesting fireworks/very costly lesson.
Plasma cutting is done from electrode to material so that is ok, but the pilot arc is always started from electrode to nozzle, meaning there are 20KV going through them.

OK so with the hyperterm powermax 105 the ohmic connector is touching the nozzle. If I bend it out it is not shorted anymore.

So here it is, I bent out the metal connector around the black shield so it is not touching the nozzle.

This ok to use ohmic sensing? Sorry, cant get iphone to focus on the torch at that closeup.

If you are not counting the THCAD output it may be that you have the THCAD set for
1X mode and you have the encoder filter on.

In 1X mode the THCAD will output ~1/2 usec pulses which will be ignored by the
encoder input if the filter is on. If general is probably best to run the THCAD in
1/32 mode.

PCW wrote:

If you are not counting the THCAD output it may be that you have the THCAD set for
1X mode and you have the encoder filter on.

In 1X mode the THCAD will output ~1/2 usec pulses which will be ignored by the
encoder input if the filter is on. If general is probably best to run the THCAD in
1/32 mode.

Thanks PCW:

The encoder.velocity seems to be ok now. It is obvious I dont know how the concept of this is working.

Theoretically, I should be able to jog the torch down and the ohmic probe light should come on if all is ok?

So I am getting ohmic-enable so it knows it is probing,
but I am never getting ohmic-probe. So I guess that leads to the voltage component.

I will admit, I dont know what I am doing with this. How to calculate thcad-fullscale, I assume it is thcad-10 so should have 10 here.
ohmicsense.volt-divider - how to calculate this
ohmicsense.ohmic-threshold - dont know how to calculate this. I assume this is the level it needs to drop to to trigger the probe?

Ohmic sensing relys on using contact between the torch and the material to act as a switch which is closed on contact.
Sometimes the torch will be designed so there is contact inside the torch tip between the two electrodes that "blow" apart on ignition. If that is the case, your torch is not suited to ohmic sensing. You could check this with a multi meter by seeing if you have continuity between the torch tip and the material without the ohmic clip touching the torch tip.

I think however all is not lost. I think on your machine you need to get a special shield cap to use with Ohmic sensing.
Ref: www.hypermaxonline.com/Hypertherm-851473...ermax105_p_1081.html

I would go back to your dealer to get clarity on this.