I'm at wits ends.. tired of wasting steel

[mitchw123456]

I have a 2x2 Wright CNC table with a Proma "compact" thc and using mach 3. I don't use the machine what I would consider much but its getting to the point where it isnt useable. It never fails it will start out cutting decent and then the torch will raise to the point is doesn't cut completely through the work piece but then towards the end it decides to get its act together and starts working again. Adjusting the voltage on the thc makes zero difference on it. Also I've tried starting in different parts of the table to see if it would only raise at one area and its still random. For the life of me I can't figure this out and most importantly i can't continue to literally turn new plate into unuseable scrap metal. Does anyone have any suggestions? Thanks in advance!

[ctgolfer1]

Wow, that sucks , must be frustrating.
Are you sure your air pressure is not dropping after so much time cutting.
I have been using my Langmuir table with no THC and it does just fine. Would much rather have THC but I get along.

Hope you get it worked out.

Good luck!

[acourtjester]

There are a few questions the need answering. on you Proma while cutting does the voltage of the arc change.
You have a set voltage this is what the THC is to follow to keep the cutting height at it correct distance. the other is the actual voltage of the arc and this is to be compared to the set voltage to tell the torch to move to keep them the same while cutting.
the other thing is the voltage tolerance which is how far up or down the arc voltage can be before the THC tells the torch to move to correct to the set voltage. To large of a voltage tolerance and the torch will not respond as it should.

[mitchw123456]

There are a few questions the need answering. on you Proma while cutting does the voltage of the arc change.
You have a set voltage this is what the THC is to follow to keep the cutting height at it correct distance. the other is the actual voltage of the arc and this is to be compared to the set voltage to tell the torch to move to keep them the same while cutting.
the other thing is the voltage tolerance which is how far up or down the arc voltage can be before the THC tells the torch to move to correct to the set voltage. To large of a voltage tolerance and the torch will not respond as it should.

The voltage is fairly consistent while cutting. I’m not sure though how to set the voltage tolerance? I have tried book setting and also done the line tests with no improvement.

[acourtjester]

here is the setting location on the Proma

tolerance.JPG (67.51 KiB) Viewed 1003 times

tolerance.JPG (67.51 KiB) Viewed 1003 times

[mitchw123456]

here is the setting location on the Proma
tolerance.JPG

Thanks for the info you’re always very helpful! What would you recommend running it at?

[acourtjester]

Try the 4 volt to start the lowest is 2 volts

[mitchw123456]

Try the 4 volt to start the lowest is 2 volts

Thanks it’ll be a few days before I can try again but I appreciate it!

[KMWren]

you may need to replace the limit switch on the z-axis.

[mitchw123456]

you may need to replace the limit switch on the z-axis.

Doesn’t have one that I’m aware of.