Hypertherm 65 3/8 plate

[HaasMetalDesigns]

I have a lot of 3/8 plate to cut (1300 pieces of 2by2 with a 1in hole) I do not want to sit and clean that many pieces
But I can't get a nice clean slag free cut
I did a few test at .063 torch to work distance. Book say 45ipm but I do get a lot of slag on the piece
So what I did was cut at 50ipm then drop down 5ipm on each cut see picture
How should I go about this to get a clean cut?

[plain ol Bill]

Check Hypertherm's specs for 3/8. I use a Hyper 1250 and get beautiful cuts with very little slag on the bottom. I use 65 Amps, pierce @ .100, cut @ .06, 41 inches per minute.

[HaasMetalDesigns]

hypertherm's specs for 3/8 is 65 amps pierce @ .15 cut at .06 45ipm. I try that I did not get good results

[WyoGreen]

Whenever I go to cut a new thickness of metal, I do a bunch of straight line cuts to find the best combination of parameters to get the cut quality I want.
I turn off the Torch Height Control, make sure I'm at book spec cut height, and try different cut speeds, noting the resultant voltage. I check each cut until I get as good a cut as possible. On my machine, most of the time my cut speeds and cut voltages are not the same as the book specs. I suspect every machine is a little bit different, perhaps because of variables such as the air supply, moisture in the air, maybe even elevation. I end up with vary little slag, mostly just on the corners.

Steve

[tnttracy]

a couple months back i had a job cutting about 20ea 4'x8' sheets of 3/8" plate with a pm65 at 65amps. at book settings and had very little dross.

about the clean up;
-tumble them, even with the amount of dross your getting throwing them in a cement mixer will likley take all of it off

-put them in a muratic acid bath. i do this with most of my pieces. i let them sit over night then i hit them with a pressure washer and that normally takes care of 90% of any dross.


cut quality;
looks like your not getting very good air flow and/ or warn cosumables

-be sure are inlet psi is maintaining during the cut 90-120psi, i dont don tlet mine drop below 100

-double check the machine settings, its not set on 'gouge' is it? looks like it could be

-be sure you have good cosumables and the torch is clean. on thicker plate i notice the torch likes to transition to cut height right into the slag puddle from the pierce and damages the tip. i use mach3 and dthcii. to stop this problem i set my cut height the same as pierce height in sheetcam, that way the thc brings the torch to work height at just enough of a lag to not dive into the slag puddle and cosumables last for ever. also some anti spatter can help.

hope this helps

[jimcolt]

Dross is caused by:

-Cutting too slow
-Cutting with torch too high.
-Allowing the metal to get too hot.

1. Experiment first with speed.....do test cuts with incremental increases in speed. 45 inches per minute using 65 amps is the minimum dross free speed....so that is why the spec is in the manual, however some plates have different levels of manganese, carbon and silicone, all of which affect dross formation. Increase speed maybe 2 ipm per cut......usually you will find a speed that will produce dross free bottom edges.
2. Be sure the torch is really at ,060" during the cut.
3. If you are cutting a lot of these parts....maybe they are getting too hot. Some nesting software for plasma skips to cuts that are further away from previous cuts in order to allow the plate to cool....minimizing dross and warpage.
4. Worst case, spray some mig welding anti-spatter spray on the bottom of plate.

Jim Colt Hypertherm