THC problem

When you say the result is the same do you mean that the feedback does not work?
(the the Z axis down not move down when the torch voltage is too high or up when the torch voltage is too low)

It was clearly backwards before since Z moved up when the voltage was already too high

Can you plot whats happening with Halscope on these pins when you do your trial cut?

thc.arc-ok
thc.z-pos-out
thc.volts
thc.vel-status

BTW a correction velocity of .01 (or -.01) is 10 mm/s (at 1 KHz servo thread)

Note that there is no acceleration limit other than the
Z stepgens maxaccel parameter so this must be set appropriately

As PCW stated a Halscope will give a better idea of what is going on.

After reading this again...

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,

Test 3: volt setting is 124V, Velocity tolerance 5, Volt tolerance 1
Result: head is crashed into the plate, thc.volts is changed betwen 124-135V, thc.zpos-out is below -30

If test 1 started at 100V and went to 115V the voltage was going in the right direction, the head was moving in the wrong direction as PCW has stated.
But if the head was moving down the voltage of the plasma cutter should also be going down.

Test 2 looks like it is just going the wrong way.

Test 3 also looks like the voltage is again going in the wrong direction for what the head is doing.

What happens if you set the voltage tolerance to a really high number, say 50?

Rick G

Hello!

I attached two picture.

Screenshot_1 is made during the cutting.

The other is showed that if I disable THC and enable again the Zpos-in and Zpos-out will be different. Is it correct?

I tried to set the voltage tolerance 50, but the head also go down.

Thanks!
Csaba

Well in screen shot 1 the thc volts requested on the screen shows 1 volt.

Rick G

First I had made a screenshot from a trial cutting (with 1V voltage tolerance) as PCW ask.

Than I made another test with 50 voltage tolerance.

Sorry for my inaccuracy!

OK!

I unerstand, and see what is the problem.
I am just a little bit slow .

During this time I made a quick test:
I give the requested voltage by numpad and press enter after it, but in this case the thc.volts-requested does not changed (showed in the hal config).
It is only changed if I press the up or down arrow.

It is working but need to calibrate the correction velocity.

Thak all of you the kindly help!

Regards,
Csaba

Hello!

At last I had time to calibrate the THC .

I foud the followings:
- when the plasma source is on the voltmeter shows imput voltage what is almost fluctuate betveen 0 and 0,05 volts (watched in the hal).
I use lowpass filter (lowpass.0.gain 0.01) for make it better, but despite of that it is not continously 0V.
- during cutting the torch moves up and down like a sinusoid with +-0,3mm amplitude.
- the thc.correction-vel is 0.004 what is fast enough to follow good the plate surface.

I think the velocity scale is not correct. It is 0.00037866834 at the moment.
How can I calculate the thc.vel-scale?

Thank you!

Csaba