Aluminum vs. Steel

[TrinityFabworks]

Just started cutting aluminum with my plasma table. Just curious if it usually isn't as friendly to work with as steel or what? I was starting to think that I was getting everything dialed in....then I started with aluminum.

[Old Iron]

Post the System, plasma make you're using because, that will make a difference on the settings.

[TrinityFabworks]

The strange thing is that my torch is squared up, cuts steel with barely any bevel. Aluminum, has a huge bevel on any x axis movements, and the y is beveled pretty good on only one side.

[WyoGreen]

If I remember the explanation right, there is an interaction between the plasma stream and steel that helps the cutting action. That interaction does not occur with Aluminum, it's strictly heat doing the cutting.

I'm not sure of the exact terminology, but that's the gist of what I remember, Steve

[robertspark]

Aluminium has a much lower melting point than steel
~ 1/3 to 1/2 the temperature of steel
https://www.engineeringtoolbox.com/melt ... d_860.html

So if you think about the hot plasma + the swirl of the gas it will have more chance of "sweeping" away more material in the swirl.... given steel will be less likely to be affected given its the center of the plasma gas / arc which will affect the material.

take the PMX 45 (non XP, non duramax), with shielded consumables.
Air pressure will be the same with the consumables given the machine won't know the difference between the material
However say 1/4" material
Mild Steel is cut at ~60 to 75 to in/min, 120v to 116v @ 0.06" cut height, airflow 360 scfm (cold) to 320 cfm (hot)
Aluminium is cut at ~80 to 100 in/min, 123V to 120v @ 0.06" cut height, airflow 360 scfm (cold) to 320 cfm (hot)
https://www.hypertherm.com/Download?fil ... &zip=False

Or with a Duramax Torch:
Mild Steel is cut at ~48 to 72 to in/min, 130v to 127v @ 0.06" cut height, airflow 390 scfm (cold) to 320 cfm (hot), 0.061" kerf
Aluminium is cut at ~70 to 104 in/min, 137V to 132v @ 0.06" cut height, airflow 390 scfm (cold) to 320 cfm (hot), 0.063" kerf
https://www.hypertherm.com/Download?fil ... &zip=False

Interesting the change between the standard torch and the duramax torch with regards to the voltage and feedrate changes for the same material

The proportion of feedrate for the duramax torch between the materials is also higher than for the standard torch

You still haven't stated what plasma cutter you are using.

You also want to make sure your cut direction is correct or you will be badly affected by the swirl direction if cutting the wrong direction especially with aluminium having a lower melting temperature.

https://www.hypertherm.com/en-US/learn/ ... t-quality/

[TrinityFabworks]

Thanks, I am using a miller spectrum 625 x-treme. There isn't much out there for cnc operation with this plasma cutter. I did however find my issue. It was a consumable issue. I put new consumables in, and it went back to cutting square. They were almost new/factory consumables from miller. Not sure why they failed so quickly. The orifice on the tip and the electrode didn't look out of norm.