DIY Foam Wire Cutter + Project

[zan777]

Hey Guys,
I've seen lots of plans everywhere for DIY foam cutters and though i'd give it a crack at making my own from some relatively cheap parts. First of i must state that I am no electrician and can't verify how "SAFE" this device is, although as far as me testing it goes i haven't really found any problems.

Any parts i didnt have i bought from Jaycar Electronics (Jaycar Electronics - Better. More Technical.). I will post the price and product codes of the items i bought.

You will need:

• Scrap wood (amount will depend on design)
• Screws of various lengths (had these also)
• Nichrome Wire (This wire heats up and can withstand high temps). I bought mine from jaycar its .32mm thick and comes in a 4m length [WW4040 $4.95]
  
  
• Hookup wire (I just grabbed 4m of the blue stuff at Jaycar at .70c a meter) [PS0528 $2.80]
  
  
• Power Supply - I started off with an old adapter for a wireless router. it was rated 12v and 1 amp. it worked alright although i swapped to a Toshiba Laptop charger rated 15v and 5 amps and it cuts alot easier
• (optional) DC line in adapter - if you want to still be able to use your DC adapter for whatever its original use was then buy one of these adapters. unfortunately the one i bought didn't find my adapter so i just wired up the adapter with some tape [PS0528 $3.45]
  
  

Here is my put together version:

Now i didn't take photos as i went but i will try to explain.
steps:

1. at the top of your 2 "arm" lengths of wood cut a slight groove for your nichrome wire to sit in
2. line your "arm" lengths against your base piece of wood and pre-drill for the "pivot" point of both your arm lengths attaching to the wood.
3. screw your arm lengths into place.
4. measure out your nichrome wire. you want enough so that when the arms are at right angles the wire is taught. also add about 10cm overhang each side for attaching.
5. to create a connecting between the blue hookup wire and the nichrome wire wrap lengths of both wire around a screw and then screw it into the wood about 2cm from the end of the "arm" length of wood.
6. Do the same on the other side ensuring the nichrome wire is taught when you screw the screw in
7. you can tape the hookup wire to the side arms to stop them getting in the way. If you bought a DC line in connecter you would attach the two blue wires to it. in my case i placed one wire "inside" the adapter part, and the other "wrapped" around the outside. then just tape in place
8. If you've done everything right you should have a DIY foam wire cutter!

Some notes on the design:

• If you only use one screw to attatch the arm lengths then they can fold down to for easy storage:
  
  
• The pivoting arms can make it quite hard to keep tension in the cutter + hold the item you want to cut. if portability isn't an issue i would use 2 screws to keep the arms in position
• The cutter cuts polystyrene foam really easily but it has some troubles cutting through the canned "expander foam"

This project was just mean't to be a little DIY project at home. In the end i spent $11.20 all up but could have bout only half the hookup wire and the DC line in adapter which would bring the total cost to $6.35

If you have any comments or questions please post (especially if its to say i have just created one almighty fire/electrocution hazard ). I will post in here what have been using it to create soon