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Plasma Cutter

I recently bought a Chinese 40 amp. plasma cutter. A Riland Cut-40.

The "manual" is pretty rudimentary. I have never owned a plasma cutter and I have a couple of questions about operating one.

The manual specified air pressure is 4.5 Kg/Cm - about 65 PSI. Does one vary the air pressure depending on the thickness of the material being cut? The machine has an ON/OFF Switch, an Amperage Control Dial 0 - 40 A and an additional switch, not mentioned the manual, an on-off-on switch marked "2.5 SS" and 5.0 SS". Does anyone know what this switch might be?

I have googled Riland USA and downloaded their Cut-40 operating manual, which is a copy of the original "English Language" manual, that I have, that has been edited into English.

However, the Riland USA manual still doesn't show the switch I mentioned. It isn't logical that the switch is any kind of a "range switch" as the amperage control covers the cutter's entire amperage range and the only other thing I can think of that might be controllable is the air flow timing although that seems redundant, but maybe not.

Any help will be greatly appreciated.

Bruce in Bangkok (brucepaigeatgmaildotcom)

Reply to
Bruce
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No, the air pressure is constant. On my Hypertherm there is a regulator on the back. I just hook into my 90 PSI airline and adjust the regulator to the proper pressure for the plasma cutter. In the manual it looks like yours is setup the same way.

I looked at the manual too and the only thing I see mentioned that it may be for is if you have the model Cut-40D which can work on 220V and 110V. It could be to switch between the 2 but as you said, they don't seem to mention the switch in the manual. Is it on the front or the back of the machine?

Have you called or emailed them to ask about it? They have a phone number and email address on the last page of the manual.

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

Reply to
Keith Marshall

Yes. Usually the machines have a regulator and gauge as part of the front panel. If your machine doesn't, you could just plumb one permanently into the back. On my machine, which is a Lincoln Procut

55, someone took the recommended air pressure settings for various material thicknesses and marked them right on the regulator gauge. There really isn't a problem with too much air pressure, however, in thin materials, excessive air will increase the width of the kerf and the amount of slag produced.

Most plasma cutters have a postflow cycle which cools the nozzle and tip after extended cutting. However, this is not usually user- adjustable except maybe via an internal trimmer potentiometer on the circuit board. It is possible that this could be an option of 2.5 seconds of postflow versus 5 seconds of postflow. However, this seems pretty short, since the postflow cycle on my machine is about 15-30 seconds.

Good luck with your machine ww88

Reply to
woodworker88

Thanks for reply.

Yes, there is a air pressure regulator on the back of the machine.

No, the cutter was bought in Asia and is a 220 VAC only model.

The switch is on the front of the machine about half way between the ON/OFF sw. and the amperage adjustment. On another group someone suggested that it selected the "post air flow" although the versions shown in the manual don;t seem to have the feature and I don't understand why, using compressed air, it would even be necessary as there is no appreciable savings in turning the air off quickly.

I e-mailed the dealer, in Singapore, but no reply as yet.

Bruce in Bangkok (brucepaigeatgmaildotcom)

Reply to
Bruce

It would be easy to test if the switch is indeed post flow. As for savings, there could well be savings if you are in the field somewhere feeding the plasma cutter from a nitrogen or compressed air cylinder, not a compressor. A SCUBA tank is a good source of clean dry air and you'd get ~15 min of use from a typical 80cf tank.

Pete C.

Reply to
Pete C.

To those who responded to my questions - thanks.

I feel a bit stupid. I went back to the shop this morning and sure enough the switch is for the post air delay. (Why didn't I think of that?)

Adjusted the air pressure to 4.5 Kg./Cm2 and Lo, it cuts like a champ.

Bruce in Bangkok (brucepaigeatgmaildotcom)

Reply to
Bruce

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