Edge start and hole cuts in thick metal

[Jcam450]

Hello, I am a newbie with plasma cutting. We have a Hypertherm 65 mounted to a JD Squared 4' x 4' plasma table and we use Sheetcam to send the files to their software. I would like to cut some items from 3/4" plate but the Hypertherm 65 will only pierce 5/8" according to the charts. I have seen posts about doing an edge start for the out side cut and drilling a small hole in the center of the larger hole I want to burn out which I assume I would do an edge start on as well. Can anyone explain the procedure for doing an edge start on each of the cuts.

[djreiswig]

Just either put your start point on the edge of the material, or if you want to do the hole method, step through your code until you get to the pierce and mark where the pierce will be. Then move the torch and drill a hole so the edge is near the center of the pierce. You have to leave enough material so the arc can start to cut. Then start your code over and let her rip.
Also, you don't want a pierce delay if you edge start.

[djreiswig]

If your table is capable of doing a ramp pierce, I've had good luck piercing 3/4" using that. Make the plunge rate the same as the feed rate and no pierce delay. It will rooster tail the sparks away from the moving torch.

[Jcam450]

Thanks, I’ll give these a try.

[SeanP]

What I do is place a small circle over the pierce point's on the part in sheetcam, then using a drill operation peck mark each pierce point, then drill with a 3-4mm drill and then run the cuts with a tool for edge starts, it works well for a few parts but I don't want to many parts to do!

I have attached a sheetcam job file that you might follow better.

(it's a pity this forum doesn't allow .job file to be uploaded?)

[adbuch]

Sean,
I was not able to open your pdf file.
David

[djreiswig]

It's a .job file, not a pdf. You can't upload job files so he tricked the site by changing the extension.

[adbuch]

It's a .job file, not a pdf. You can't upload job files so he tricked the site by changing the extension.

OK. Thanks.
David