THC problem

In hal pin the thv.volts is 0,65..V in the case of 0V input

In this case adjust the Offset to get 0 volts which should also bring the 21 volt at 20 closer to correct.

Test 1: volt setting is 135V, Velocity tolerance 5, Volt tolerance 1
Result: head is crashed into the plate, thc.volts is changed betwen 100-115V, thc.zpos-out is below -30 after a 100mm cutting.

Test 2: volt setting is 100V, Velocity tolerance 5, Volt tolerance 1
Result: head is rised, thc.volts is changed betwen 120-136V,

This seems to indicate that the THC is working but the correction direction is in the wrong direction.

Rick G

Also in your testing for the THC to make a correction it needs signals that...
The torch is turned on.
The arc transfer / arc O.K. is on.
The THC is enabled.
The velocity is within tolerance.
The torch voltage is out of tolerance.

Rick G

Did you get this sorted out?

Rick G

Hello!

Sorry, but We had to hold up this project.
Of course we simmulated all the needed signal.

I do not have any other idea.

Thanks,
Csaba

As Rick G said its looks like the correction direction is wrong.
If this is wrong Z will aways "runaway" from the setpoint
instead of following it when the THC is enabled

How can I modified the direction of the THC correction?

Its easy enough to fix the feedback direction (inverting the Direction pin is a simple way)
but this will also reverse the Z commanded position from Motion.

This may work:

Reverse the Z direction by inverting the direction pin (so feedback is correct)
This can be done in HAL

Reverse the Z axis scale (OUTPUT_SCALE) so Motion is correct


I would set the correction velocity very slow for testing, then verify
that if the setpoint voltage is higher than the torch voltage, the torch moves up
and vice versa

Sorry I am not a professional user. Can You detailed it how can I do that?

You could also try changing the sign of

thc.correction-vel

thc.correction-vel float rw

The amount of change in user units per period to move Z to correct

Rick G

Hello!

I tied to cut whith the changed thc.correction-vel parameter (it was 0.01 and modified -0.01).
Cutting velocity is betveen 2400-1680mm/min.

The THC settings:
Vel tolerance: 1500
volt: 79
volts tolerance: 1

The correction direction is changed, but result is the same that it was.
The head is only rised or only sinked.

I wached the arc volt in the hal config. It seems good (It was neer to the value given by the Hypertherm).

Can be that the correction velocity is too slow?

Thanks,

Csaba