Machine Torch tip catching when cutting across a slat.

[Jason Bauer]

Ok we have been having an issue with the tip catching/dragging with the THC on our 4x4 with PM65.

What I've determined is happening is we get some blow back slag every once in a while when crossing a slat. Its always a slat crossing that it happens at, but doesnt happen at every slat.

We have the 1/8" thick steel slats with a 4x4 water table. We will have a very nice cut going, then get a tip drag which moves the material and then screws the whole cut up. This happens with old and new consumables.

Has anyone had this before? Any thoughts on solutions other than removing slats where ever it is going to cut?

 

[LECS-Chad]

You might want to consider altering the PIERCE HEIGHT up a little to adjust for the dross that comes form the pierce. Verify your settings and assure you are running your pierce height higher than your cut height. Pending on what system you have there are a few other things to try.

 

[Jason Bauer]

Yep, Pierce is at .15" cut is at .06" as specified by hypertherm. This isn't happening at the pierce, this is usually at least a few inches into the cut. It will have a nice clean cut going then sometimes when crossing a slat the slag builds up and catches the tip.

 

[Matt]

are you in auto or manual mode on the avhc?

 

[Arkansas Metal Art]

Might consider making new slats with 1" points on them every 5" or so.

 

[Jason Bauer]

Auto Mode.

 

[Matt]

Try raising the voltage few volts

 

[jimcolt]

I agree......sounds like the torch is running closer than .06", and you always will get a little height variation when running over the slat...as it alters the arc voltage. If you raise the arc voltage by 5 volts, the real time cut height will rise about.020". Put on some #6 shade glasses and observe the torch to work distance......06" is just shy of the thickness of a nickel. My guess is it is closer than that......so increase the voltage maybe 2 to 3 volts at a time until it looks right.

If you cut slower than "book" speed at the book voltage...the torch will run closer. So slower speeds mean you must dial in a higher voltage to maintain correct height. Another thing...as the torch electrode wears, the torch will get closer to the material. It is common to need as much as 15 to 20 more volts near the end of electrode life....than with a new electrode. Jim Colt Hypertherm