plasma stops constantly

[jerryk]

First day trying to run some parts and the cnc stops constantly. I had just updated the acorn software. Ran a new z calibration. stopping during cutting and was able to resume probably 10 times then the last time it wouldn't let me resume.

report_20D77882D92D-0819226477_2023-10-14_16-54-37.zip

(8.31 MiB) Downloaded 35 times

I'm a newbe, so it's probably something i'm doing wrong.
Thanks for any help .

[Joey]

Hello Jerry

Voltage Readings from your THC Look pretty Clean. Thats good

Most of the plots don't have a lot of THC Z Movement. Looks like the Job your running doesn't allow for X and Y to come up to speed very often. X and Y isn't even making it to 50% of the target velocity.
Are these very small zigzag moves?

It Looks like the Voltage is high most of the time. I'm guessing the torch does not like being so far away from the material and is flaming out. Or The Material is very thin and with the Slower than Target speed of the Job the Kerf width is getting Really wide and forcing the Arc to travel furth to reach new material. Thus raising the voltage until there is a flame out

What Material are you cutting and what velocity. What amperage is the Plasma box set too?


Your Calibration Looks Pretty Good.

[jerryk]

14ga, 40 amp, 221 ipm I checked the distance from the material after the z calibration and it was .060. I don't know if it could have changed during the run.
I checked the torch height today after thinking it was still at cut height after possible flame out from yesterday. It was .097. Is that high enough to cause a flame out like you described? o What could cause it to change while running? Thought something could be loose but I checked and everything felt tight.

Thanks for the help!

[Joey]

I'm thinking it is a combination of the torch being slightly high and the feed rate not being up to speed.

What touch off device are you using?
Is Smoothing on or Off in the profile manager for these Jobs?
Does this material warp at all when cutting?




Check out this Plot,
This was the Last Plot captured in your report from 10/14/23. THC was never able to Lift the Torch During this Cut. If anything the THC did react for a split second and tried lowering the torch due to the voltage being high.
Looks like the Job stopped not long after the pierce. Looking at the plot the Voltage is pretty high even after the X and Y starts moving after the pierce. Then at the Very end of the Plot the Voltage keeps rising until finally the voltage drops out (flame out). X and Y motion still continues as no breakaway or job interruption had been received yet. Then finally the job is interrupted as there hasn't been any THC voltage for a while.

[jerryk]

using omic torch tip touches off.
smoothing was off
no warp that I can tell
Did torch touch off today and it is 1.010 instead of 1.00 where it was yesterday after calibration.

[Joey]

Try the Job with Smoothing ON. With Smoothing on it may help Keep the feedrate Up.

Is the Ground clamp connected to the material?

What type of motors and drives do you have?

[jerryk]

Ground is through the table
Motors are cheap stepper online ones
Drives are gecko 203v
I'm only running one motor on each axis so I'm sure its under powered. just want to make some stuff to sell before sinking another 2 or 3k into this thing to have 2 motors on the y axis.
Would it be better to lower the amps to 25 and run slower?
It's an old lockformer table I've retrofitted.
Just ordered a 3:1 reduction for the y axis to give it more torque and higher revs per inch travel. right now its 1 rev per 1.2 inches travel.

[Joey]

Yes I would lower the Amperage and run as slow as you can.
Might have more time for the THC to keep the Z at the cut height.

Attach the work clamp to the material in case the hypertherm doesn't like the resistance.

[jerryk]

So is my z axis being 5 revs per inch too slow? Or is the acorn too slow to respond fast enough with my acceleration set at .2? What acceleration do you recommend on the z axis?

Thanks

[Joey]

Your XY velocity in the JOB never gets to at least 90% of the profile feedrate. This is set in the THC config settings. THC will not enable until the antidive velocity ratio if X/Y is above 90%.

Smoothing should help get your speed up. Or turning the amperage down and cutting at a slowing feedrate should also help.