Cutting round holes

[brewman114]

I have seen many posts here with pictures of the final cuts that show small holes cut that are near perfect. I would like to know how that is achieved. I would seem that I can get a perfect circle until I cut smaller than an inch, then it begins to oblong the hole. Help please!!!

[WSS]

The leads are an important part of it, almost as important as your machines motion. But you also can gain from locking (freezing?) the thc and slowing the ipm down to around 60% of the normal F (feed) speed. Experiment with different speeds on different size holes. Attached is a 1/2" piece with two 11/16" holes that were within .015", just had a little ding from the lead out to knock off with a die grinder. the holes were cut @14.4ipm and the torch locked at .125" then back to thc and 24ipm for outside cut.

WSS

[brewman114]

Your talking about having the holes cut with the THC turned off and set a specific height right. And then the rest of the cut to operate normally with THC on?

[WSS]

Yes, the smaller the hole the higher the specific height. This is because of being closer to the pierce crater and resulting booger. A water based anti-spatter helps too, it sheds the pierce booger and lets the torch track better and not stutter on the top side dross. Pierce from dead center of the hole if you can and 90 degree out to the cut, if your machine has good motion.

WSS

[brewman114]

Cool, I will give it a try. Thanks

[jimcolt]

If you send me your direct email I will send you a presentation called best practices for plasma cutting holes.

Jim Colt jim.colt@hypertherm.com

I have seen many posts here with pictures of the final cuts that show small holes cut that are near perfect. I would like to know how that is achieved. I would seem that I can get a perfect circle until I cut smaller than an inch, then it begins to oblong the hole. Help please!!!