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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

bokorugro_111 wrote:

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.

Thank all of you the kindly help!

Regards,
Csaba

That is a bug in PyVCP.

Put the tip voltage in a watch window as you cut to calibrate the correction velocity. It does help to have a piece of bowed material so the torch moves up and down to find the correct number for correction velocity.

JT

Hi,

Trying to use your setup and I have a problem.
when I move the axis z manually, it moves correctly (speed and acceleration is correct)
In the program, when the axis z going down in search of material (float switch) screwed up a lot higher speeds exceeding the capabilities of the machine.
I would add that in all axes have trapezoidal screw 4mm powered by the same engine and the same drivers.

Changing the settings for axis 2 affects the work in manual mode, but not automatic.

Any idea?

By the way, the manual does not mention setting the enable signal for drivers

I have found the solutions:

in stepper.hal

line:
#setp stepgen.2.maxvel [AXIS_2]MAX_VELOCITY

We need to remove #

I thought i wrote an explanation about that on the howto file ???? I don't remember now but i am glad you made it work.
Now if you could be bothered to share some pictures of your setup, it would be nice.
Let us know how it goes.
Regards,
Tom

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

I'd say you have too fast correction velocity, unfortunately it is not properly named as I could not think of a good descriptive name for that. That number is the distance moved per period so it needs to be very small number to prevent hunting up and down. Something in the neighborhood of 0.00002 works for me.

JT

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).

Do not expect to see a rock solid 0 here, it will wander a bit due to resolution. However if you set your voltage correction to 1 volt or more that slight a variation should not matter.

I can tell you from experience that as John said the correction amount needs to be very small. Set high enough on my machine it looked like a sewing machine needle going up and down.

Rick G

Hello!

I had changed the value the correction velocity from 0.004 first to 0.002 then 0,0004.
It was too slow to make correct correction.... but the head did not make the small up -down movement.

In my case the dimensions are in mm and as I hope in yours are in inch.
With this small correction velocity how fast is the correction?

Thanks!
Csaba

Yes, John and I have set up in inch.
Look a little earlier in this post as PCW posted an example of the correction speed based on the servo thread.

Rick G

Please help! working on a customers machine. Setting up Torch height control.
THC works great in manual jog mode. But when you run a file, the vel. status light never comes on. Its like its Backwards. Please help. cant fiqure out what to do. Thanks

I figured out a work around. I commented out thc.requested-vel and now it's working.
That trick disables the corner lock feature, but it's working great.

it's helpful to post your hal & ini files or your full config as an archive , so we can see what is going on ,
Also you do not mention which THC you are using .

post your files

Hi all
I'm looking at upgrading to include a THC, I've found this one at a price within my budget.
proma-elektronika.com/index.php/en/products/thc.../compact-thc-150

Does anyone have any experience of this with LinuxCNC and a home grown plasma table?

Are they easy to install or will I need another budget for more kit and a degree in who-knows-what?
Any thoughts comments greatly appreciated.

Cheers

Danny

I built my plasma table and currently use Mesa 5i25/7i76 with the THCAD card. Cost about the same as your up/down THC and includes the motion control cards with I/O.

JT

Tom,

I am setting up my homebuilt CNC (in Scotland) using a proma-elektronika DTHC and am using your config files, with pins changed to match my setup. Test mode on Proma gives the correct UP, DOWN, and ARC OK signals visible in Linuxcnc. I can't get the system out of ESTOP; the ESTOP connections are spread across two separate .hal files and I'm not sure how to configure them. The pin is correct as tested with a different config for the same machine. Halfiles attached - can you help me with this?


Andy