? for Jim Colt plain vanilla aluminum

[Loyd]

Jim,
.250 thick 3003 aluminum (the nasty kind).
What settings/tips would you suggest on a hypertherm 1250 with plasmacam?
I wiped nozzle dip on both sides ran 60amp unsheilded tip @ 45 amps, 55ipm it did what I would consider a fair job
but just wanted to compare notes. I was cutting a part 4.375 in diameter with 89 .250 holes. Kind of like
a shower drain. Dross was pretty heavy at times and I would have to reset the height control for every
part for it to cut "properly".
Thanks,
Loyd

[jimcolt]

Must be a typo or something.....how did you fit 89 .250" holes in a 4.375" part anyway?

I would use the 40 Amp shielded consumables.....the shield helps a lot on aluminum by keeping the front of the torch from arcing to the aluminum spatter. It also is a good idea to run your consumables right at their rated amperage. Using a 60 amp nozzle at 45 amps reduces the energy density of the arc....effectively allowing it to wander more.

I just did some 1/4 aluminum a couple of days ago.....and I used my Powermax45.....so the settings would be different. I actually followed the specs in the Hypertherm manual and it worked pretty well.

Jim

[Loyd]

Thanks Jim. I tried to use shielded but the "growth" that would build up on the top of the aluminum would catch on the tip. I don't know if you have worked with 3003 alum before but it is very gummy, nasty to machine just not nice stuff at all. As far as the 89 .250 holes? I will attach a drawing. I also threaded the O.D. with an 8 tpi so it could be screwed into the pipe fitting. I made 41 of them. Tell you what.....I'll see if I have time to cut one today and take a picture of the part w/o any secondary operations. Also, thanks for the tip about running at the rated amperage....I didn't realize that.
Loyd

4 inch strainer.jpg (62.84 KiB) Viewed 1563 times

4 inch strainer.jpg (62.84 KiB) Viewed 1563 times

[jimcolt]

If you are getting acceptable quality on aluminum on a part like this....you are doing quite well! This type of part is usually a good candidate for an abrasive water jet......laser does a poor job....and the plasma usually heat affects it too much. Nice work!

Jim

[Loyd]

Thank you Jim, The parts did come out quite nicely. I would skip around the hole pattern. The only real issue I had was the machine would wind up way too high on the next part to initiate the cut. I would just cut one part, then reset the torch height for the next and so on. I will try a different alloy next time. I just had a 4x5 foot piece from another job.
I really appreciate your input on this forum I have learned a lot from your posts.
Loyd