Basic heating circuit - Complete noob needs prod in the right direction

[Lexman]

Hi all,

I'm in a little over my head here but would be very grateful of any advice.

I need to build a very basic circuit but have no experience in electronics other than basic bits at school over 15 years ago.

I need to create a simple portable heating element consisting of a length of straight nichrome wire (8cm), running off 2 AA batteries and able to reach temps hot enough to cut polystyrene.

Very early stages, so suggestions very welcome.

Thank you in advance.

Best,
Lexman

 

[Nigel Goodwin]

No 'circuit' required, just a length of the nichrome wire - start long, and shorten it until you get the required temperature.

Bear in mind the batteries are going to have a VERY short life.

 

[atferrari]

Yes, forget the batteries.

I've read this site, and found it informative (maybe even too much for you).

Hot Wire Foam Cutting*-*www.dansworkshop.com

 

[Vizier87]

LOL. Or one of the crudest methods to cut plastic I used is to use those cheap blades, heat them up using candle fire.

 

[Lexman]

Thanks guys, seems like trial and error is the way to go then. Would nichrome be the best to go for? What thickness would you recommend?

 

[Diver300]

I suggest a soldering gun like this Soldering gun - Wikipedia, the free encyclopedia

You can bend copper wire to the shape that you want and use that instead of the soldering bit.

 

[3v0]

Any suggestion on the gauge and length of wire to start with.

 

[Diver300]

I've used about 10 cm of solid 2.5 mm2 wire. I really don't think that you can damage those soldering guns easily, but mine did get a bit hot after extended use. The open circuit voltage is about 0.2 V

 

[3v0]

I may have to give it a try. Need several hundred Styrofoam ducks for a charity event. The idea is that a huge pumpkin dropped from a crane into a pool will fling the ducks. The greatest distance wins. Still looking for cheap ready made ones.

Much like this but with a crane and a larger pumpkin
YouTube - Bauman's Giant Pumpkin Drop