Has anyone built a homebrew plasma cutter? I was looking at new ones,
and while they're not insanely expensive, I own a lot of the stuff
that goes into one already (compressor, transformers, etc.) and I
dislike multiple redundancies :-)

Seriously, though, has anyone given this a try?

Thanks for your time.
Dave

On 2 Apr 2004 16:56:13 -0800, (DDoerschuk) wrote:
Has anyone built a homebrew plasma cutter? I was looking at new ones,
and while they're not insanely expensive, I own a lot of the stuff
that goes into one already (compressor, transformers, etc.) and I
dislike multiple redundancies :-)

Seriously, though, has anyone given this a try?

The power supply is very similar to a HF start inverter TIG supply with
one very big difference. Output voltage is much higher. Plasma cutters
run at about 350 arc volts while TIG is about 20 volts. The high voltage
relatively low current arc dumps much more energy into the plasma,
and less into the consumables (electrodes). This is the key to plasma
torch operation.

High power inverters are tricky beasts at best to design and construct,
high voltage ones even more so. Expect components to explode, and
expect flashovers, during development. Very subtle and hard to resolve
problems often crop up at the frequencies at which inverters operate.

Much of the circuitry of a plasma cutter is there to protect the equipment
and the operator in case something goes awry. You're dealing with potentially
lethal output voltages and relatively high currents. This isn't something I'd
tackle at home with limited knowledge and limited budget.

Gary

Some guy on ebay is selling instructions to build one. Don't know if
they are worth it.
I recently bid and won a new 30amp plasma cutter for $400. I just
recieved it. Haven't tried it yet but it looks darn good. I report on
the operation in a couple of weeks.

Simon Shabtai Evan

DDoerschuk wrote:
Has anyone built a homebrew plasma cutter? I was looking at new ones,
and while they're not insanely expensive, I own a lot of the stuff
that goes into one already (compressor, transformers, etc.) and I
dislike multiple redundancies :-)

Seriously, though, has anyone given this a try?

Thanks for your time.
Dave