We Love Cutting Metal With The Thermal Dynamics Cutmaster 42

Portable plasma cutter works right out of the box with author's "wimpy" air compressor.

Published on: Jul 26, 2012

Over the years we've tested several plasma cutters, from a suitcase-size unit that we didn't have enough air to support, to smaller machines that worked but were a lot of trouble.

The Thermal Dynamics Cutmaster 42, however, is more what we've been looking for truly portable metal cutting and the ability to operate without sophisticated compressors and air dryers.

The 26-pound Cutmaster 42 comes ready to plug in -- to 120 VAC or 208/240 VAC -- and features a 20 amp output for 120 VAC 15-amp circuits; 27 amps on 120VAC 20-amp breakers, and 47 amps on 208/240 VAC. The output is plenty for work up to 3/8ths materials and with care you can cut half-inch stock.

At 26 pounds and not much bigger than a lunch box, the Cutmaster 42 from Thermal Dynamics offers a portable and easy-to-use way to quickly cut steel, stainless steel, aluminum and other metals.
At 26 pounds and not much bigger than a lunch box, the Cutmaster 42 from Thermal Dynamics offers a portable and easy-to-use way to quickly cut steel, stainless steel, aluminum and other metals.

Within 10 minutes of unboxing the Cutmaster 42, I had hooked up my portable compressor and plugged the cutter into a 220 VAC circuit in my garage. Moments later I had zipped the top off a bulk Freon bottle, and cut a three-inch hole in the side of it -- freehand -- for a small cooker project I'm working on. The cut was like that of a hacksaw, except for where I didn't steady my hand moving around the top of the bottle. (One learns quickly!)

Clean cuts vs. slaggy cuts demonstrate the ability of the Cutmaster 42 to outperform a gas cutting torch on materials up to 3/8ths inch in speed and cut quality.
Clean cuts vs. slaggy cuts demonstrate the ability of the Cutmaster 42 to outperform a gas cutting torch on materials up to 3/8ths inch in speed and cut quality.

Then, Beef Producer Editor Alan Newport and I teamed up in his shop to do some videos of the machine and give Alan his first experience with a plasma cutter. Running 220 VAC we sliced up scraps, compared cuts between the plasma machine and an oxy-acetylene cutting torch, and Alan used a windvane for a pattern to cut out some letters just for grins. (See video)

The Cutmaster performed flawlessly and struggled only when we tried cutting some half-inch steel that had welds and 1/8" plate welded to it.

Portability, dual voltage input, and the ability to operate on the output of a small portable compressor, make the Thermal Dynamic Cutmaster 42 a very handy tool.
Portability, dual voltage input, and the ability to operate on the output of a small portable compressor, make the Thermal Dynamic Cutmaster 42 a very handy tool.

Both of us were impressed with the machine's compact power, and intuitive ease of use.

The controls are simple -- a single dial for current based on voltage inputs. The internals take care of the rest of the Cutmaster's settings. Once you turn it on, it senses if sufficient air pressure is present (85 to 100 psi) and once it's satisfied, it lights a green pilot light indicating a "go." From there, the operator only has to pull the trigger on the SL40 torch to light a pilot arc, and apply that to a grounded work project to begin cutting.

Both compressors used in our tests supply about 6 scfm air flow at 90-100 psi, so one doesn't need a special compressor to use this plasma cutter.

The torch is simple to service and consumables in the tip of the torch are easy to replace.

The Cutmaster 42 is a fine machine in my book, and would be right at home in any farm shop or service truck.

For more information visit www.thermal-dynamics.com.