Melted a Powemax65 retaining cap

[Bigtoy302]

I was cutting some 3/4" plate the other day and I was almost done with my cut when I noticed a small flame coming out between the retaining cap and the shield. My nozzle went at the same time. I did do a edge start on the plate. Any Ideas Jim?



Another thing is I can not get this thing to cut very straight holes. I am getting almost .030 taper on a .375 hole in 1/4". My powermax45 would do .015" taper on the same hole. I have tried different cut heights and speeds. I tried 45 and 65 amp nozzels. My 45 was way better at taper on 1/4" and 3/16" but the 65 does very nice on 3/8" and 1/2" I get a good positive bevel with the 65 no matter what height or speed I run.

[jimcolt]

I'll forward this to our engineering guys....we'll get some response from them...can you send your direct contact info to my email? jim.colt@hypertherm.com


Thanks, Jim

[magma-joe]

Bigtoy302,

Are you still using a metal clamp around the retaining cap to hold your hand torch? If so, perhaps the clamp is holding some of the heat build up while cutting at slower speed on the 3/4"? I'm not sure about the PM 65 but on my Powermax 1250 retaining cap there was always a small amount of air that escaped from the top of the retaining cap. At first I thought it was a bad O ring on the torch body but when I changed it the air still escaped. I assumed it was for cooling. In your youtube video the clamp holding the torch is covering this area. Just a thought....

Magma-joe

[jimcolt]

Actually....one of our process engineers asked to see a picture of the torch mounted in its holder. He suspects metalic dust may be acumulating, and is causing arcing from the torch bracket to the shield, through the metalic dust....which will damage the retaining cap. The torch should not be mounted by the retaining cap unless the bracket is non-conductive.

Jim