on a 12v car charger set up can you put the dimmer switch between the charger and the bow or does it have to go between the wall outlet and the charger?thanks
I use a 12V charger wired directly to (I think) 24 guage nichrome, about 24 inches at maximum stretch.
My charger is switchable up to 6 amps, and at the highest setting is just barely acceptable (to me) for cutting foam. On a 8’ block of 1lb eps foam, it takes me around 2-3 songs on the radio to make a full pass from end to end. Most times I wish it was hotter so it could cut faster.
The point of all this is to say you may not even need any kind of dimmer switch with a battery charger. I’d say to experiement a bit before making it more complicated.
I also use a 12v car charger. I’ve changed wires a few times, experimenting. I’ve found out that the size and length of the wire from the charger to your bow can change the heat of the cutting wire. The size (gauge), length and type of wire you use to cut can change the heat of the cutting wire also.
I now use 22 gauge stainless steel wire (from the hardware store), 10 amp on the charger. I used to zig-zag the wire because the wire looked hot at the edges but that left the foam with zig-zag cuts, now I just pull straight and the cut is a lot smoother.
Les
ps - I heard that Stainless steel wire from a MIG welding machine was the best. My brother is a welder and I got some from him but it is a bit larger in gauge than what I’m using now so haven’t tested it yet.
Heres a cheap option, but it’s a bit more work!
It is absolutely perfect though.
I bought an electronic kitset “DC motor speed controller”, that requires you to solder up the circuit board.
It’s like the model railway transformer things, but can handle 10 amps at 24 volts, the railway ones tend to be small and weak, from what I saw.
I added an extra component that allows me to run 40 amps at 12 volts - won’t need that though!
Cost me about US$20 total, and about 4 hours soldering.
It has a dial that I can crank up the power, perfect fingertip control, and I can go as hot as I like.
I park my car near my shaping bay and hook up to it’s battery.
I’m using 22 AWG Nichrome, and I don’t think i’ll ever snap this piece. I bought 30 feet of it anyway, so i’m set forever.
If your on a budget, and think you can do some basic soldering, then this is a way to get something that works as well as a professional setup.
Kit