Thicker plate piercing strategies?

[Eric C]

I have a STV 5x10 table with the optimum controller and a hypertherm 85 smart sync plasma . I’ve fought some of the controls and had to really learn the quirks of their system. What I wanted to know about other brands is how do you tackle piercing holes in thick plate like 3/4”- We make a good deal of baseplates and parts with 13/16” holes. When I pierce with a new consumables, they get ruined in a few holes. Any advice or strategies like pre drilling(not sure how to start on that) would be great. Thanks!!

[djreiswig]

If you're using SheetCam, try using the ramp pierce. I don't do much thick plate, and since I have a 65 I use edge starting when possible.

[Joe Jones]

If you can drill a simple 1/8" hole at a specific point, you can pierce at the edge of the hole and that will be the same as cutting in from any edge.

Joe

[Eric C]

If you're using SheetCam, try using the ramp pierce. I don't do much thick plate, and since I have a 65 I use edge starting when possible.

No sheetcam, my machine came with the optimum software. I don’t know if I can use sheet cam.

[Eric C]

If you can drill a simple 1/8" hole at a specific point, you can pierce at the edge of the hole and that will be the same as cutting in from any edge.

Joe

That’s what I’d like to do- but I don’t know how to accurately line up multiple drilled pilot holes with the start points of the torch.

[Joe Jones]

It is a bit tricky, but it can be done.

Joe

[FabLab]

In my opinion your best bet is to pierce in the center of the hole and use a straight leadin I would experiment with raising my pierce and cut height on the holes as well, but .812 hole in .750 it's going to be tough to get good consumable life.

The other thing I have done in the past is setup a job that just does the piercing, use old consumables for that job, switch to new ones and run a second job that does the cutting..

[weldguy]

Hypertherm chart says your pierce height should be at .250" so first off I would check to be sure that your machine is piercing accurately at that .250" height. Often what you set on the screen and what it actually is out at the table can be different.

If you find that your torch is lower than .250" when piercing adjust your height to get an accurate .250" pierce height and see how that goes.

Let us know if you pierce height was accurate or not and we can go from there.