I live in England and want to make a hot wire cutter to shape a board from XPS or EPS. I have done a fair bit of research on here and elsewhere and am still confused about how to make a cutter. Tried some swg 26 0.457mm Nichrome wire with a battery charger but it did not get hot. Someone suggested using a laptop power adaptor. I have one - output 20V 4.5A. Would that work? Please someone with local knowledge who can recommend what I can use? Desperate to start shaping.
There must be some 240 volt rated Variacs out there. Check out local Hobby Shops and their sites. Using the Variac is really the right way to go about it. Craft supply stores will have at least an answer as to where to locate one.
I now use a 12v car battery connected to a stainless welding rod, I tried a few different things and this (for me) has been the best set up. good luck.
Thanks.
Could I use something like this? Only £20
Just keep turning the dial up until its hot enough to cut the foam? Too much and the wire melts?
or this?
http://www.modelsport.co.uk/?CallFunction=ShowSpecification&ItemID=34985
What sort of output range do I need?
Sabrina’s Man, the second device you posted is what you want, the former is really a “chopper” that uses the peaks (highs and lows) of the current (think sine waves) the latter is the correct device. You don’t need much wattage, but to be safe start low and experiment. Good Luck.
hi, if you are making a board or two i would just use a battery charger and a guitar string , the two thinist ones are ok , i use this set up , its fine for a few boards ,
two pieces of wood screwed to a cross peice to form a large capital H, the H needs to be wider than the board, a bungee on the top of the H to keep the string tension ,two screws on the bottom of the H ,wrap the guitar string around the screws ,attach the screws to the charger and away you go , easy and cheap, pete
when i was looking for a variac, i found bunches of them that were used by guitar players...
i guess they hook them up in line with their amps? or make amps from them? or???
do you know any guitarists?
I got everything I use in Maplins. I use resistance wire, a 24v battery charger and a large button switch. The 24v battery charger overheats the wire, but i use the button to control the flow of current and therefore the heat of the wire.
Thanks guys. Lots of useful info here. Another question. I want to hotwire the rocker. I have 2 options. Make 2 rocker profiles out of plywood. Clamp a 4 inch piece of foam between the ply and then hotwire. Do several of these and then laminate them. Second option. Single block of foam 8’ x 24" x 4" clamped between ply profiles. Is that being too ambitious wanting to hot wire through 2 foot of xps? Do I need thicker wire, more amps? It would be great if it worked. 1 rocker cut, no multi laminating. quicker and cleaner than sanding it down by hand.
Have a look at the toy electric train kit. I used to have an old “variac” from a train set which did the job perfectly.
it was me that used a LAP top Charger- it was a 12v 5-8 Amp one and thin Guitar wire from the music instrument store. Go to you local IT guy maybe they have more laptop charges lying around.
Have done a test with .457mm Nichrome wire and a lap top power adapter with an output 20V / 4.5A. With the width of the wire set at 36" it successfully cuts through the foam. Now I will be able to cut the rocker into a single piece of foam without a stringer.