[MrUno]

I have a Hypertherm MAX100 that has been in service for a number of years. Over the past few weeks we have worked through a few issues with it. The head went bad on it, and the pilot arc relay CR1 had enough metallic dirt on it to keep it from engaging.

Got that taken care of and it just doesn't have the cut quality it used to. On 1/4" plate at 100 amps it rapidly builds up dross on the nozzle, which then makes an arc to the workpiece and doesn't cut very well at all.

Today I was cutting some 3/4" plate and noticed an arc pattern inside the nozzle and on the electrode. I had to slow the cut speed down 10% - 15% because of the lag from the top to bottom of the cutting arc. The cut surface is not as smooth as before either. It has more of a crinkly finish. Also if the 1" hole in this part lands on a slat it causes the cut to become "unstable" and wander around a bit.

Anyway I'm hoping someone can give me ideas of what to check/replace or what might be causing this problem.

Thanks

[Simonh1959]

We had a problem recently with a rough cut edge and cured this by changing the swirl ring.