Thread: Hot Wire Cutter - Curved cutter?

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My memory suggests that I once saw a site somewhere where somebody had made a curved hot wire cutter, I think from simply some stiff/thick wire (almost like coat hanger wire). The idea was to cut out pieces of foam (think of an ice cream scoop idea taking scoops of foam out of a larger piece).

I've been Googling for ages and have come up with zilch.

Anybody know if there is any info out there about this, or am I going mad? I really don't think I am as I recall thinking that whatever the person had used, it wasn't the proper wire (ni-chrome?) that I used to make my normal cutter and thus the resistance (or is it conductivity?) wouldn't be any good - that's why I'm thinking that it was like a coat hanger or the like they used. But apparently it did work.

Thanks all.

My Tippi foam cutter comes with a few different curved cutters. One as about a 1/2 wide. The other is about 1" wide. Is also has a cutter 1" wide with 90° corners. There were even two straight wires to bend into any shape you wish.
Here's a video of the guy I bought mine from at a local Hobby Show. In the video, you can go to 6:10 to see the different shapes that come with the cutter, along with a couple he bent to custom shapes.

i have one of these ( and love it ) is it what you mean ?
http://hotwirefoamfactory.com/-018-Freehand-Router.html

That shows that there are other options other than a straightforward horizontal or vertical cutter with straight wire, so it suggests I'm not mad!

However, what I recall seeing was a home made cutter, but using thick wire and quite large - something like a stiff wire curved/bent into whatever shape you want and about 12" (perhaps more) wide, meaning you could take a scoop around 12" wide and deep out of a piece of foam (if you had a piece thick enough) - so you'd come out with a semi-sphere (or half/one side of a ball). It was essentially the same principle as the one in the video, but home made and on a larger scale.

I mentioned like an ice cream scoop? Well look at this one and imagine the part that moves round when you press the trigger to release the ice cream from the scoop - imagine a similar action with a piece of curved/bent wire but on a larger scale, where you would 'scoop' out a curved piece of foam (very similar to the shape ice cream you'd get from using this scoop).

i have one of these ( and love it ) is it what you mean ?
http://hotwirefoamfactory.com/-018-Freehand-Router.html

I have one of these, and it works great. You can bend it into a loop and use it as a scoop if you want. I was just using it to work on a pay-it-forward surprise I'm making for someone.

I want to scoop a beachball size piece of foam so from that you can see the size I'm talking about.

I know I've seen it somewhere on the net.

I made a hot wire foam cutter out of an old pistol style soldering iron. I simply replaced the soldering tip with a piece of #10 copper wire. You can bend the wire to almost any shape, just be sure that the wire doesn't touch itself. Here's a pic showing a couple of different "blades". One is a long straight for deep carving, the other is in the exact shape needed to cut HO scale tunnels.

Originally Posted by Doc Doom

I made a hot wire foam cutter out of an old pistol style soldering iron. I simply replaced the soldering tip with a piece of #10 copper wire. You can bend the wire to almost any shape, just be sure that the wire doesn't touch itself. Here's a pic showing a couple of different "blades". One is a long straight for deep carving, the other is in the exact shape needed to cut HO scale tunnels.

Thanks Doc! That's what I mean exactly, but on an even bigger scale - take your tunnel making wire and increase the size by 4 or 5 and that's what I want and think I've seen somewhere before.

Thing is, do you think it would lose its effectiveness to melt foam as the size (and length of wire) increases?

Do you have any more info on that copper wire - what thickness it is and any other special characteristics? I don't think we'd have the same rating system over here as you do there.

Doc - do you mean 10 AWG copper wire (about 2.5mm thickness) like shown here;

http://www.reuk.co.uk/buy-10-AWG-POWER-CABLE.htm

From googling it seems this may be what you're referring to. Thing is I also found out about resistance based on the length of wire and that means I may need to increase/decrease the thickness based on the overall length. Any ideas? Let's say the wire I use has to be around 2ft long, bent to the shape I want. Any ideas on the thickness I'd need to make it actually melt the foam?

You also say to make sure the wire doesn't touch itself, but the picture you included seems to show the deep cutting wire has been twisted against itself - or is that just how it looks?