Noob -- machine settings questions

[flathead]

Me and a couple buddies pooled some money together and bought a plasma table for our shop. We would eventually like to make parts for ourselves to use on our hot rods, and maybe to sell to other hot rodders. So far I have been playing around with the machine and have a few questions for you guys that know what you are doing.

How much kerf should I allow for, when using different thicknesses of steel, so that I get parts with accurate dimensions? Are there standard settings that I should be using? Also, what about rules of thumb for feedrates and plasma amperages?

the machine I'm using is a MG Industries 5 x 10 w/ Burny 2.8 controls and 100 amp plasma. I'm also using Autocad LT for drawings and Turbonest to convert the drawings to G-code.

So far, I haven't found anything in Turbonest to compensate for kerf offsets or any other machine setting. However, the Burny allows me to input things like kerf, feedrate, and pierce settings. Is this the way all plasma tables are set up? It seems like it would be easy to make these settings on the PC instead of the machine controller.

Unfortunately, I don't have manuals for anything. It's all been trial and error up to this point. I have been able to make parts, they just seem to be either slightly oversized or undersized and sometimes have a lot of slag around the cuts. But it has been fun. Thanks for any input.

[jimcolt]

Flathead,

Kerf compensation is usually done when post processing your drawings. By post processing.....this is when you align your parts on the size plate....and when you add lead ins, lead outs for the plasma to start/stop on each part. You may also be able to kerf compensate right on the Burny 2.8 operator screen. The actual kerf width depends on a lot of things....power level, plasm system design, gases used, cut speed (slower equals wider kerf), torch to work distance (height), wear on the plasma nozzle.

If your plasma is a Hypertherm...you can download manuals from the web site www.hypertherm.com

Does your MG machine have a THC (torch height control) system?

I'd be happy to offer advice getting this running as needed...I'm a former stock car racer....now into hot rods! I havea PlasmaCam table with a Hypertherm Powermax1000 plasma for my needs!

Jim Colt

[flathead]

jim,

thanks for the help. I do have a Hypertherm machine. It is the Powermax 1650. I was able to download the manuals from the Hypertherm site. It has exactly what I'm looking for as far as the recommended settings. I guess I should have looked there before posting.

Also, the machine does have a torch height control, but so far, I haven't attempted to use it. It was not being used before, so I'm not sure if it works. The THC is labeled ATC Innerlogic, Inc. I have been able to locate the manual for it online as well although that company has now changed its name. I will try using it the next time I get a chance.

We bought this machine from a fabrication shop that went belly up. One reason was that they were not very well managed. Their maintenance program was not the greatest either. That's why I didn't get manuals. They had lost everything. Also, no one was there when we picked up the machine to give us any training on anything. I know the machine works well based on some of the parts that they made with the machine. It's just a matter of me learnig how to operate it correctly. These manuals are a great starting point. Now I just have to convince my wife to let me hang out at the shop all night every night to play around and learn what I'm doing.

[jimcolt]

Sounds good.

The Innerlogic (now known as Kaliburn) THC is a fairly good THC....although I don't think it has initial height sensing....so you have to manually jog the torch down to the pierce height. This is ok if you are not doing high production.....you need to stay at the machine while its cutting to ensure that in case of plate warpage it does not pierce too low or too high.

If you need any help getting the whole thing figured out...feel free to ask me for help!

Best regards, Jim Colt

[mcsteve]

Sounds like a nice machine you've picked up. The Innerlogic ATC does have initial height sensing as well as automatic torch height control if it was installed with the Innerlogic control box. You can download the manual from Kaliburn web site or have them fax one to you. Activating the ATC will help prevent the torch crash that Jim mentioned.