help with 3/8" aluminum

[integrusllc]

hello all, i am new to the whole plasma cutter and cnc table industry.
i learn more and more everytime i use it. i do ok with steel but am struggling with aluminum.

i have a 2x4 burntable with hypertherm 45 and follow the setting in the manual for the material im cutting

setting:
amps 45
cut height .06
pierce .15
cut speed 42 ipm
kerf .060

here are a couple pics of what my results look like. is there something im missing or is this the best i can expect for this thickness of aluminum

[Redneck]

I've only cut aluminum a time or two, and my cuts looked about like that too.........as I have since been told, you need to use nitrogen instead of compressed air for aluminum and stainless cuts to get a smooth cut. Just my 2 cents.

[Diverdude]

looks like your speed is to high, try slowing it down a bit. Your probably running at the maximum capacity of your plasma torch so you can't turn up the heat so you will have to adjust it with speed. the angled marks in the cut give it away.

[jimcolt]

The "book" cutting speed for a Powermax45 on 3/8" aluminum is 33 (42 is max speed) inches per minute.....this is listed in the mechanized cut charts in the operators manual. Diverdude is correct...the lag lines indicate that you are simply cutting too fast.

Make sure you are using the correct consumables....mechanized shield especially. I would recommend a little bit higher pierce height (I use about .22" on aluminum) and spray some mig welding anti-spatter spray occasionally on the shield after assembling it to the torch....this will help to keep the aluminum spatter from sticking.

Aluminum will not cut like steel....it will always have a rough, porous edge. Also...because it sinks the heat rapidly from the cut area your thickness capability is diminished as compared to cutting steel. 3/8" is near the max capability with a Powermax45 (mechanized) on aluminum.

Nitrogen, contrary to popular belief....will not notoiceably improve the cut edge on a low powered plasma system. Air is roughly 20% oxygen and 80% nitrogen....an the oxygen content in air actually reduces the surface tension of molten aluminum, making the dross fall off easier than when using pure nitrogen. I suggest sticking with air.

If you cut a lot of 3/8" aluminum you would be better off with a more powerful plasma. I use the 45 amp process with excellent results up through 1/4".....above that the results are similar (although a little better due to lower cut speeds) to yours.


Jim Colt Hypertherm

hello all, i am new to the whole plasma cutter and cnc table industry.
i learn more and more everytime i use it. i do ok with steel but am struggling with aluminum.

i have a 2x4 burntable with hypertherm 45 and follow the setting in the manual for the material im cutting

setting:
amps 45
cut height .06
pierce .15
cut speed 42 ipm
kerf .060

here are a couple pics of what my results look like. is there something im missing or is this the best i can expect for this thickness of aluminum

[integrusllc]

Thanks for all the info. I'll try the slower speed

[integrusllc]

If I move up to a more powerful cutter, will I get signicantly better cuts?

[jimcolt]

The edges will be squarer (with a larger Hypertherm such as the Powermax65 or 85), there will be less dross, the consumable parts life will be better. The cut edge will still be relatively rough and porous..

Jim

If I move up to a more powerful cutter, will I get signicantly better cuts?

[integrusllc]

Ok, thanks. So no way to get a smooth edge cut at that thickness aluminum with a plasma. And would it b worth it to go with a bigger plasma. Do u know if my mechanized torch will work with the larger units

[jimcolt]

Laser and plasma both provide a porous finish on aluminum, water jet is best....but far more costly. Machining is even better...but even more expensive. The Powermax45 torch is only for the 45.

Jim Colt

Ok, thanks. So no way to get a smooth edge cut at that thickness aluminum with a plasma. And would it b worth it to go with a bigger plasma. Do u know if my mechanized torch will work with the larger units

[integrusllc]

Just trying to way options since this is just a hobby and just spent a bunch on the table and torch - less than 2 weeks old

[Bigrhamr]

I've got a 45 and cut 3/8" aluminum with it using by the book settings for best quality. Compared to steel the edge is rough and porous but still worlds better than the results you have had so far. I wouldn't give up on the 45 unless you need to do lots of 3/8" or thicker, it's a great machine.

[hooked]

hey jim and the rest of the guys are correct on the speed issue for the parts shown! but, none of the folks here have asked what type of alum. you are cutting? type of material is a big issue, if it 3003 which is real soft or 5052 h32 which has great strenght is real nice to weld but if very formable with both a box brake or a cnc press brake. Jim and the rest of the industry will also tell you plasma is 90% carbon steel and stainless cutting. I had great sucess with a 1070 hypertherm and a manual gas consoled we could alter the gas settings for the alum. I presently cut alum 5052 H32 all day everyday! with bottled air and nitrogen, with great edge quailty and as many have told me, our edge quality looks like a water jet cut it. hooked!

[ralbert72]

One more thing you may want to try that I have had some success with to keep the dross at bay--- First get a sacrificial piece of the 3/8" aluminum and just do straight scrap cut offs until you get it right. My innertherm 45i does just fine on 3/8 diamond plate ---What I had to do was turn up the air pressure to the torch to about 80 psi instead of the usual 65 psi. Either way you have to experiment to get the perfect storm of heat, cut speed and air pressure to get the best results..It takes a little time then write down you settings so as not to forget in the future. No matter what I set the table for I still get some dross. It is just a way to minimize it so clean up isn't so much work.

[integrusllc]

Thanks for all the input. It's not necessarily the dross that bugs me, looking for a cleaner edge