Hot Wire Foam Cutter - REVISED

[BCR751]

Well, since I've had no replies to my search for a Tippi foam cutter, I'll try another tack.  I currently have a Woodland Scenics foam cutter.  It's the wrong configuration for what I want to do but I may be able to modify it if I can find the correct wire.  I need some nichrome (I think that is the right stuff)) wire not larger than 1/16" in diameter.  Anyone know where I can find some?

Doug

[jimmo]

I'm not sure if this is the exact stuff but if it isn't they have more...
http://www.amazon.com/Genuine-AtomizerWick-Nichrome-Gauge-Resistance/dp/B00TKV8ZRK/ref=sr_1_2?ie=UTF8&qid=1450214597&sr=8-2-spons&keywords=nichrome+wire&psc=1

[BCR751]

I looked into this a bit more and now know that trying to modify a Woodland Scenics unit to take a larger wire won't work.  The WS unit uses #32 nichrome wire and it's power supply only puts out about 500 mA at 12 volts DC.  To use a #16 wire would require a power supply capable of just a little over 8 amps at 12 volts DC !!  A little much for the WS unit .  If I want to do this project. I'll have to build my own power supply and the parts to do it aren't cheap.  Sure wish I could find a Tippi.

Thanks for the info jimmo.

Doug

[peteski]

You should be able to find thinner gauge nichrome wire (eBay would be a good place to start).  There is no need for a DC power supply. A simple 12V AC transformer (1 or 2 Amp) can be bought for less than $20.  You could even use an inexpensive wall-wart supply. Lots of those are sold at surplus electronic dealers like All Electronics or Electronic Goldmine.

EDIT: I just ran an eBay search for nichrome wire and got 601 hits. You can get it on a wide range of gauges (the search result even has helpful additional searches like "nichrome wire 30 gauge").

As far as power supplies go, try AC adapters or DC adapters at All Electronics.

[basementcalling]

I have a Tipi that just quit on me.  Think I got it from Mike Lecht  on the Greenberg circuit.  Hot write foam factory is usually at Timonium,  but I always found them overpriced.

I also have a 2 D cell powered craft foam cutter from AC Moore. Slow and steady and cheap as heck.  Looks like a postal mailing tube, a spring, two metal caps, a wire holding rod,  and an on off switch that simply makes contact with the rim of the end. But it works on this foam.

[fire5506]

I have used a Weller soldering gun to cut foam. I used 16 gauge wire bent in the shape I needed and put it in the gun in place of the soldering tip. Worked fine for me. I already had the soldering gun and used scrap wire, so there wasn't any expense for me.

[BCR751]

You should be able to find thinner gauge nichrome wire (eBay would be a good place to start).  There is no need for a DC power supply. A simple 12V AC transformer (1 or 2 Amp) can be bought for less than $20.  You could even use an inexpensive wall-wart supply. Lots of those are sold at surplus electronic dealers like All Electronics or Electronic Goldmine.

EDIT: I just ran an eBay search for nichrome wire and got 601 hits. You can get it on a wide range of gauges (the search result even has helpful additional searches like "nichrome wire 30 gauge").

As far as power supplies go, try AC adapters or DC adapters at All Electronics.

Yes, thinner wire is available but I need to be able to use it to dig out creek and river beds, hence the requirement for a heavier gauge.  A #14 nichrome wire would require a current of at least 8 amps to heat up to the normal 600F temp.  I don't think a wall-wart could supply that kind of current.

I found out that the Tippi is no longer being manufactured so that's not an option unless I can find a decent used one.

The soldering gun with heavy wire sounds like it might work.  What type of wire was used i.e. copper, steel, ??

Doug

[peteski]

The amount of current required depends on the thicknes and length of the wire along with the desired temperature.  Companies such as Digikey or Mouser electronic sell transformers which can supply the current you are looking for.  Those are bare-bones transformers so you will have to build your own enclosure.

Here is a 100W (12.6V AC @ 8A) transformer for $31.
http://www.digikey.com/product-detail/en/241-8-12/595-1044-ND/952914

[Chris333]

Long ago I built my out cutter using a formed wire in a wood block. It was shaped to cut roadbed profiles in foam. I used an old transformer I found at work with a dial. I just turned it up till it worked. If wanted I could crank it up and vaporize the wire 

I don't remember what wire I used, but it would sometimes get black char marks that I just scraped off.

Now I just use those long snap off blade razor knifes for all carving work.

[fire5506]

Yes, thinner wire is available but I need to be able to use it to dig out creek and river beds, hence the requirement for a heavier gauge.  A #14 nichrome wire would require a current of at least 8 amps to heat up to the normal 600F temp.  I don't think a wall-wart could supply that kind of current.

I found out that the Tippi is no longer being manufactured so that's not an option unless I can find a decent used one.

The soldering gun with heavy wire sounds like it might work.  What type of wire was used i.e. copper, steel, ??

Doug

If I remember correctly I used 16 gauge copper wire. I was using it as a straight knife style cutter. I used about 6" of it. Worked fine cutting blue foam.