my hot wire outline cutter

[supuk]

So i finally got fed up with cutting outlines having tried various ways and wanted a way that was quick clean and gave me something that needed very little tidying up.

I had been using a router previously which gave a nice vertical cut but was messy and always had to finish up with a saw as the router was not deep enough.

So last night i set about making a hot wire to do the job it is a small bow with a turn around pully at the top leading too a set of springs for tension. it allso has a slim roller baring to keep the wire off the template and running smooth and all so takes into account for the met back of the wire.


I have had it up and running and it has given some perfect cuts however i would like to make a few improvements to the electrical side and im hoping some one may be able to help out. At present i have it running of a 12v battery. It cuts great however it would be nice if it cut a little faster. at present i am just using stainless steal wire. i have the top wire on a crocodile clip so i can move it to increase resistance.

(Question 1) with the crocodile clip were it is will the only resistance be between the + and - or will the springs and pulley always be effecting it?

I have it up to a temperature now were the wire is snapping quite quickly however it would be nice for it to cut a little faster

(Question 2) will increasing the thickness of the wire and the current increase the temperature and cutting speed?

and finally what is the difference over say the stainless wire im using and nichrome wire?

i expect i will make improvements as i go ( a switch will be one of them) but if any one else can think of anything feel free to chip in.

ps. i deliberately didnt make the bow two deep so it was easy to control but does mean you just have to quickly cut the bulk off first with a standard large bow.

[TallDude]

I played around with the thicker hotter with a number different materials. I use custom foam shapes on houses I design and build. On one house I built I had about 800 Lin. Ft of 14" eps crown on the eaves of the house. The entire driveway was full of pre-hotwired blocks of foam standing on end. In hind sight I just drewl thinking about about all that foam.
Anyway, the company that cuts all my architectural foam gave me some of their heavy flat wire you can bend in to shapes. 'Rails!' I thought. Running at speed, meaning the gets fed into the hot wire like a table saw, and it does increase production. You slow down even a little and the heat just plumes off the wire. If can find a piece, I'll show you what that looks like. I can tell you that eps gets rock hard when you cook it. Just picture throwing a Styrofoam cup into a fire, you get the idea. Slow with a thin wire ( get the nickel guitar strings) and the min. Voltage is the clean way to go.
The off gas from the hotter wire will make you sick as well. I didn't use my hot wire on the 18' board I just did for that reason.

Talldude mobile

[supuk]

yea you are probably right the higher heat will probably cause more problems than its worth.

i have already made a quick modification by painting and then using carnuba wax on the base plate to help it slide more smoothly which in tern has actually speed cutting time up. it literally is a perfect cut every time with just a very quick pass with my 90deg sanding block to nock any small imperfections out. plus now with a smaller battery its  also cordless