Cut taper

[TexasDano]

Hello gang,
Am I the only guy still using Thermal Dynamics around here, LOL .

I have an issue. I just started trying to make some really nice cuts with 100amp settings on 1/2 inch steel.
The cuts are good as far as dross and dimensions at the top but slightly under at the bottom. If I want the cut strait down the hole vertically, what do I need to play with first. Torch setting all at recommended TD Textbook recommendations.
Any suggestions appreciated.

EDIT: the shape I am cutting is a 4.5 inch id 12.5" od doughnut.

[jmsrbrt]

From another TD owner , as with any plasma cutter I suppose, I would think you'd always have some angularity in your cut hole, but to minimize it, I would think again you'd want the torch as close to the metal while cutting as possible. But that's just my guess.

[TexasDano]

Well, I did some reading and, Jim Colt is all over the place. I read several articles of his from various sites. From what I understand I am going to start by trying 60 amp and 80 amp set ups first thing in the morning, Instead of 100amp.

[Diverdude]

I've been running a TD for almost a year now and after a lot of trys I find the cut are usually better if the torch height is less. I have been running it at 60 percent to half of the book settings and getting results I like. I also set the pierce height lower. Less misfires.

[TexasDano]

Thanks for the advice guys. When I came in this morning I ran the part again at 80 amps, 40 ipm. I also subtracted the .065 offset of the shield cap from the cut height. I got good, better results. I am going to try lowering it another .025'' when I get some time today. But it did well at recommended feed and amperage.
I also did a longer lead in perpendicular to the arc, .75'' . The THC is engaged by the time it hits the arc. Did not use a lead out. Parts are lightly attached at the end point, so I may add a .06 lead out or something to get the loose cut. I'll post some pics of the cuts this evening.