40% Foam Wing Cutter

[cap231jim]

I'm setting up a foam wing cutter and need a source for an transformer to do the job. Grainger has all sorts of transformers but the capacity I think I need (.2 kVA) is a bit pricey.

Is this too large a unit?

Is there another source? I must have thrown a hundred transformers of various capacities away through the years....toasters, computers, microwaves ect....

The cutting bow will be fairly large (55 in. or so)

Will using a thinner wire enable me to use a smaller capacity transformer?

Thanks

Jim

[mjws00]

I wouldn't overthink the power supply that much. I've seen pretty much everything from a small wall wart, car charger, battery charger, computer power supply, straight lead acid batteries. All can do the job quite nicely. It is nice to have a little control somewhere in the circuit, but that can be as simple or complex as you choose. On a bow you can control heat by moving the electrical connectors in or out a little to change resistance. Yes different size wire will effect your cut, but it isn't really about managing power, more about getting the tension you want at the temp you desire with the correct amount of burn. It really doesn't take much power, around 1 watt per inch.

One way that worked really nicely with very fine control for me was using an old brushed speed control. Just dialed in the heat I wanted with a servo tester or radio. It was sitting there and saved me the trouble of building or buying. Another friend uses a computer supply, one a train supply. A small surplus variac will get you there as well. Keep it simple, imho. Tons of good ideas on google for this one.

Good luck. Have fun.

Mike

[Tony Hallo]

I use .025 MIG welding wire, for 50" bow I need about 12 volts and 7 amps, for 60" bow I would need about 15 volts.

[cap231jim]

O.K. Thanks....

Jim