QTPlasmaC THC slow to respond causing arc loss

bevins wrote:

How can I speed up the response of the thc? Mess with the voltage? I have no idea where to look.
I did not search the forums to be honest.... but I will just looking for a quick response maybe that might help.

IT seems to be ok on thicker material but when I drop to thinner material and run at 190ipm on long cuts, it looses arc.

What is your Z axis Edit: MAX speed?

It sounds to me like your Z axis may not be fast enough to keep up as your XY velocities increase.

Also, some people have reported success with a P value of 10, and others have had to bump it up to like 20. Be careful though as too much P will cause it to oscillate due to over corrections.

If it is to slow, try adding this in hal
setp plasmac.thc-feed-rate 3000
or whatever in inches.
There is also the P value at 10 by default in the config tab of QTPlasmaC so i upped that to 12.

bevins wrote:

snowgoer540 wrote:

bevins wrote:

How can I speed up the response of the thc? Mess with the voltage? I have no idea where to look.
I did not search the forums to be honest.... but I will just looking for a quick response maybe that might help.

IT seems to be ok on thicker material but when I drop to thinner material and run at 190ipm on long cuts, it looses arc.

What is your Z axis setup speed?

It sounds to me like your Z axis may not be fast enough to keep up as your XY velocities increase.

Also, some people have reported success with a P value of 10, and others have had to bump it up to like 20. Be careful though as too much P will cause it to oscillate due to over corrections.

From the manual: Note
Setup Speed has no effect on THC speed

So I left it and didn't touch it.

My deepest apologies. I meant Max speed. Trying to help you out while the lady fills the grocery cart. ¯\_(ツ)_/¯

So, what is your max speed set at?

The pin Tommy suggests is set from the ini file. And comes from the speed you set the Z axis to.

Sorry Tommy, but it is ill advised to manually set it to anything else. This is because your Z axis may not be able to handle changes that fast. So when you suggest to change it to 3000 (ipm in this case) the axis likely can’t handle that. At some point, it will cause issue.

I did mention inches below it, 3000 in/m would be interesting !
Setting that in hal is not the best way but since i did skip those steps in pncconf i ended up with a feed rate of 0, and since Bevins is very experienced i though he might have skipped it to.
Sorry for the mess up...

tommylight wrote:

I did mention inches below it, 3000 in/m would be interesting !
Setting that in hal is not the best way but since i did skip those steps in pncconf i ended up with a feed rate of 0, and since Bevins is very experienced i though he might have skipped it to.
Sorry for the mess up...

Haha no worries, there’s been plenty of mess ups in this thread. At the end of the day, we all are just trying to blast metal with the power of the sun and help each other be successful.

Even if it doesn’t always seem like it.