Need Help!- Plasma Cutting Speed

[Profpinz]

There has been talk on the Forum on how speed rates are significantly higher when the torch is cnc controlled rather than operated by hand!

I've got a Spectrum 375 (not a high end machine by any means, and it is a machine primarily designed for hand use, but it has served me well) and I'm thinking of fitting it to my new build.

The Miller Manual recommends cutting speeds of between 8 in/min for 12mm (1/2") plate up to 83 inchs/minute for 1.6mm (16 guage) but if I CNC "control" it, will I need significantly increased/higher cutting speeds?

[plain ol Bill]

If a machine torch or hand torch are both mounted typically to the same CNC machine the cuts should be identical if pierce heights, cut heights, and torch speeds are the same. Most use a machine torch because it is simpler to use, and is a quality production tool. A hand torch removed from the machine and replaced usually has to be tweaked to get it to cut the same as before.

[xjdubber]

the speed you mention seem about right, you wont want to go much faster than that with that power source. Of course a cnc will cut faster than cutting by hand, can you tell when you travel 83ipm with your hand? you can use the whole hand torch in the machine i wouldnt take it apart as some people do just make a collar that fits around the head of the torch that i can swivel in. bring the cord down in the center of the machine with some slack and it will nicely go all over the table.

[jimcolt]

The great thing about using a plasma torch on a cnc machine is that you can control the speed...and make the speed very fluidic (not shaky like your hand). Speed and height are the two most important parameters that will help you achieve the best cut quality. Higher speeds will minimize dross, lower speeds will improve edge bevel.

Jim