How to Increase Kerf

[Stout]

I have a project that is quit large and has a lot of open lines to cut. I'd like to make these lines as wide as possible for light transmission. It's 12 gauge material. Any thoughts?

Maybe run an 80 amp nozzle at 40 amp speed?

[tnbndr]

You could use double or triple lines spaced very close so that all the material would blow away. Of course this would increase cut time also.

[icmplasma85]

Make your cut height higher, it'll make the arc wider, or make all of your open paths closed. Basically offset your open path however big you want your opening, say 1/4", and then close the two ends, maybe with an arc or radius so it is rounded slightly. I attached an example.

[Stout]

I'm trying to get the kerf up to about .100"-.120". It's .080" right now. Using a double pass at a close distance will cause arc voltage to drop and torch collisions. Or loss of arc because the arc will only have about .020" of material to keep it going.

I'm wondering about increasing the cut height. Does anyone have any experience with running the 80 amp nozzles at 40 amps? From what I have read, the amps determine kerf. Although the lager nozzles have a larger outlet. Guess I'll have to test it.

[Stout]

I just called Hypertherm support. I guess I earned unusual question of the week. They suggested a gouging nozzle. Hadn't thought of that.

More testing.

[jimcolt]

I was just going to suggest using a gouging nozzle as well. You will have to use a much higher arc voltage, lower air pressure, lower speeds.

Jim Colt

[Stout]

After some test cuts, I went with an 80 amp nozzle set to 60 amps and arc voltage set to 155 which brought the nozzle up to about .200". Kerf widened up to about where I wanted them to be. Cut speed was not changed. I did change the material to 14 gauge.

Here's preliminary shot of the artwork with a droplight behind it. No cleaned up yet so the cuts should open up just a bit more after dross removal. The piece is 95" wide and 36" tall for reference.

[plain ol Bill]

Why not just cut wider lines by using the contour tool - oops - there I am assuming things again - do you use CorelDraw?

[Stout]

Why not just cut wider lines by using the contour tool - oops - there I am assuming things again - do you use CorelDraw?

I do use CorelDraw and covered that in post 4. The cut lines would be too close which causes arc voltage to drop and torch collisions.

[vmax549]

14ga ?? Simply use a fine cut nozzle and DRAW the contour to a double Kerf width slot. If your kerf width is .050 then the slot becomes .100"wide when cut.

When modifying the drawing just do an offset of the cut line and add a loop around on one end

You will not loose the arc IF you are cutting at the proper height. At least here with a HT torch we don't.

AND you end up with very detailed cuts instead of a torch cutting TOO HIGH. Remember rule #1 proper cut height is everything in Plasma cutting quality.

Just a thought, (;-) TP

[plain ol Bill]

I used the contour tool today to cut some .70 wide lines using normal fine cut consumables w/ my Powermax 1250. Used the THC and it maintained height and cut voltage just fine.

[Stout]

I'll look into it. I've been doing this for about 10 years and have never used fine cut nozzles. Well, in my defense, I've only had the Hypertherm system for about 2 years and the Esab didn't have fine nozzles. The image below is the final product showing the kerf with single pass being used. The slots are in fact different widths due to the height control being disable on shorter arcs and then enabled on straight cuts. I was shooting from the hip on the cut parameters, but I do like it. And it can only get better.

[abmagrum]

very nice job.