Poor quality and Wavy Plasma cuts (Pictures)

[lowpull]

Norm,

How about making a new lightweight gantry and put it on the table at the same time as the other gantry. Just move the gantry you are not going to be using to the very end of the machine, move your connections to the other gantry that was stored at the other end of the table and voila. I am sure that there are other issues involved but its just an idea.

[Normsthename]

i have cut stainless recently and after much cutting of normal steel am frustrated by the quality of stainless cut. is it customary to have black jagged finish?

Hi Benergy
Have you tried all the things I have done above?
You will find that Stanless just does not cut as nice as mild steel.
My machine will cut mild steel very close to a Laser finish.
But Stainless is still very hit or miss.
Everything has to be set perfect to get a pefect cut.
Clean dry Air, good consumables, correct cutting heght, correct speed etc etc
If anyone of these is not 100% it will affect the cut quality.

How about making a new lightweight gantry and put it on the table at the same time as the other gantry. Just move the gantry you are not going to be using to the very end of the machine, move your connections to the other gantry that was stored at the other end of the table and voila. I am sure that there are other issues involved but its just an idea.

Hi Lowpull
Thats a good idea, but my Bed is only 1 metre long, so I would lose a lot of cutting area
I am planning on making a Version 2 machine over the Winter if funds allow
It will a Plasma specific machine, and it will have a bed size to take a stock 2000mm x 1000mm Sheet.
That will save me loads of time having to cut sheets down all the time!

Thanks

Andy

[Big John T]

Andy,

I made my plasma table so it would allow me to use a full sheet but the cutting area is just under 1/2 sheet. I let the excess hang out the back and sit on mobile supports (sawhorses). As I cut parts out I just slide the sheet in some more.

John

[jimcolt]

You don't say what plasma system or what process you are using....However I will guess that you may be using an air plasma to cut stainless.....and with this process , yes, the edge will have a black oxidation (due to the oxygen content in air), and will be a bit rough.

If you have a Hypertherm Powermax system and the stainless is thinner than 3/16, you may have better results by using the FineCut consumables. They will still produce a discolored edge....but it is cleaner and squarer than cuts with standard air plasma consumables as the arc has higher energy density.

If you have a water table...you can use nitrogen instead of air, and submerge your stainless 1/2 inch or so below water (assuming the manufacturer of your torch says that the torch is compatible with underwater cutting)....this keeps oxygen from ambient air away from the hot cut edge and eliminates the discoloration...although the edge may still be rough.

If you have a Hypertherm HPR130 or HPR260 system....you can use F5 (5% Hydrogen, 95% nitrogen) as the plasma gas and nitrogen as the shield gas and get a shiny, clean smooth edge on materials up to 3/16", above 3/16" you can use H35 (35% Hydrogen, 65% argon) as the plasma gas and nitrogen as the shield gas....for a shiny, clean edge quality.

Jim Colt