DIY Hot Wire Foam Cutter

Super

If you have ever gone through the mess of cutting white foam board you know what this is about. I have tried everything and the best (least mess) I could come up with is using a hack saw blade or a serrated kitchen knife. But even then the cut edges would still crumble pieces away. I always wanted a Hot Wire Foam cutter that would cut the foam easily and seal the edges at the same time but could not justify spending the money for the few times I would use it each year. Now, with the help of this amazing DIY Video I can make one myself for penny's. I have ordered the wire and already have the rest of the materials on hand to make one.

[video=youtube]https://www.youtube.com/watch?v=qzaHd-BmROA[/video]

Off The Rails

That’s pretty ingenious. I’ve seen other DIY foam cutters but many of them were a bit more complex than I thought I would need. I’ve also considered buying one from Foam Factory or another hobby manufacturer but I always ended up spending the money on other things. This looks totally “do-able” and fairly inexpensive.

Super

I will Post back on my experience once I build it. My initial question is how long the battery would last connected across the positive and negative like that. I am thinking that a mini momentary button switch might help. One that needs to be held down to make connection and when released turn off.

chrisjo

In my experience you need to have a quick and easy way to adjust the tension in the wire, which changes markedly when you apply the current. With this design I suppose you can turn one of the bolts, but I didn't see mention of that on the video.

Super

Do you have a retail one C-Jo? If so, how do they adjust the wire tension? Do you think that tension is much more affected by what gauge wire is used?

chrisjo

No, I have a (rather over-engineered) home-made one:

[url=https://postimg.cc/SJwxBXTL]

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Super

Thats a good looking DIY item C-Jo. How do you add tension in that one?

chrisjo

You turn the screw in the close-up picture, between your forefinger and thumb. That acts on the hinge.

Super

I see...brilliant. That wire looks thin, do you know what gauge it is?

chrisjo

No, I'm afraid I don't. I made this maybe 20 years ago, and obtained a stock of wire then, but the details are lost in the mists of time. However my trusty micrometer tells me it's about 0.22mm diameter, which would make it closest to AWG31. It works with a 12VDC PSU.

Super

Wow, 20 years ago...you can't be that old. This must have been passed down to you from your Great Grandfather. 😃 It is an ingenious way to keep tension on the wire, did you design that method yourself.

Watching a few more videos I see that some creations will use a small spring soldered to one end of the wire to keep tension on the wire. I may try to add that to mine. There are a ton of iterations of DIY Hot Wire Foam cutters on YouTube, I had no idea.

The wire I ordered touts itself as Foam Cutter replacement wire and is 30ga. "nichrome 80 wire for foam cutters etc 30ga 10 ft sealing etc replacement wire"