Cutting Brass with Laser, Plasma, water jet

Glen Jones - Thursday, December 20, 2007 - 6:57am

Over the christmas break I am experimenting with working on brass which is a new material for me. I am interested in any comments from people who have had experience in cutting it with the above mentioned processes. What are the advantages and disadvantages? Any tech tips I should be aware of.

I have cut plenty of SS and MS with Plasma and laser but brass is a new ball game.

Thanks
Glen Jones

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Depends on your laser.

Gene Olson - Thursday, December 20, 2007 - 9:56am

Depends on your laser.

Many of the lasers out there use light that is just the right wavelength to be reflected by copper mirrors.

ie: it may not work unless you are cutting thin material.

There are some lasers that use other wavelengths and other mirror material that may work on copper alloys but it can take a lot of power. Best ask the guy with the laser and if he has never tried copper or thought about it, make her try a sample before assuming it can or cannot be done with the equipment at hand.

Gene Olson
Sculptor
Elk River, MN

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plasma cutting

sparesomechange - Thursday, December 20, 2007 - 5:44pm

I used to run a 200 amp cnc plasma machine at a shop I worked at. I don't remember ever cutting brass, I guess it just never came up. I did, on several occasions cut up some 1" thick copper plate, and it cut real sweet. My own theory was the better electrically conductive the material, the better the cut. Our town is small though and doesn't have a big pool of experienced metal workers to trade ideas with.

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copper on plasma

Gene Olson - Friday, December 21, 2007 - 10:13am

We did a copper job with a tracer nc plasma.
The shop said the 3/16 material was a bit of a pain as it conducted heat so fast. areas adjacent to the cut would heat and cause the material to move up into the cutting head.
They ended up cutting with the water table touching the bottom of the sheet to wick away the heat.
That worked fine.

I imagine a higher powered faster moving CNC would have less of a problem, as the heat input wouldn't have as much time to collect or expand it's influence.

. . . also, our pattern had a lot of adjacent holes and patterns, so the heat was applied and reapplied. I guess the cnc corollary might be to spread the cutting out as much as possible. Normal programing is to do adjacent parts and eliminate travel time. Here we might want to kill time between cuts to let the material stabilize. (or as they did, cool the plate with tangent water bath)

Gene Olson
Sculptor
Elk River, MN

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