Hot Wire Foam Cutter

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kenstarr

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I'm fixing to build 7.875 diameter upscale of Der Red Max and as I will be requiring a custom nose cone, I've decided to try the hot cutting method of foam shaping. In the past I've used a router and a BBQ rotisserie to slap together a foam lathe mill spawn of the Devil. It works well but the mess, even with a dust collection system, absolutely incomprehensible!
Enter the hot wire foam cutter ala Jacobs-online.biz
I cobbled this together today. I'm pretty happy with the power supply. The cutting head is just a rough approach to the final product. I'd like to build one out of wood and have it look like an antique bow saw
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Sandy H.

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Looks to me like you had a fun day.

Looks like a waaaay over-engineered control box and a test set-up for the harp. Sometimes the test set-up becomes the final functional unit for sure, but I like your idea of a wooden bow-saw. Given the look of your workbench and tool organization (sure, not 100% clean, but that's because you're working), I think you'll do it even if the PVC harp works perfectly. I look forward to seeing it!!!

Good work and good motivation for the rest of us.

Sandy.
 

ep29030

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I've been using an old 12V toy train transformer to power my hot wire cutter. Works really well. I remember that someone said to buy the old transformers, because the new ones shut down under the resistance of the wire. Anyway, for $15 it's hard to beat.
 

ThirstyBarbarian

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It looks good. Are you going to post about the rest of the build and the rest of the setup for cutting the foam plug? I have a hot wire foam cutter, but haven’t built the rest of the foam lathe yet, and I’m curious how you are going to do it.
 

rharshberger

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Jacobs Online is also a good source for nichrome for igniters, I also like that they are only 75 miles from where I live all shipping is very short time.
 

kenstarr

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It looks good. Are you going to post about the rest of the build and the rest of the setup for cutting the foam plug? I have a hot wire foam cutter, but haven’t built the rest of the foam lathe yet, and I’m curious how you are going to do it.
I'm going to try! I have the foam on hand. I cut out a paper profile of the NC. Now I need to cut out a couple pieces of MDF and build the nose cone kebab rotisserie.
-Ken
 

kenstarr

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It works like a champ! I guess it's based on a turning saw. I learned about it from Rex Krueger's woodworking for humans series on YouTube. I figured the saw frame would be perfect for a wire instead of a blade! The side pieces are cherry, the cross piece is 2x4 cut down, and the tensioner is a scrap of maple.
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ThirstyBarbarian

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It works like a champ! I guess it's based on a turning saw. I learned about it from Rex Krueger's woodworking for humans series on YouTube. I figured the saw frame would be perfect for a wire instead of a blade! The side pieces are cherry, the cross piece is 2x4 cut down, and the tensioner is a scrap of maple. View attachment 486090
Nice!
 

Sandy H.

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It works like a champ! I guess it's based on a turning saw. I learned about it from Rex Krueger's woodworking for humans series on YouTube. I figured the saw frame would be perfect for a wire instead of a blade! The side pieces are cherry, the cross piece is 2x4 cut down, and the tensioner is a scrap of maple. View attachment 486090
Pretty sure I called that just over a week ago in post #2. Nice execution!

I saw you mentioned free-handing the initial discs. I assume you're going to free-hand with the wire, not a different tool. Given your woodworking hobby (which seems more than a hobby looking at the work you did on the harp), are you planning on doing a jig like is typically used to cut discs on a bandsaw and just using the wire for that or would you make a second wire 'bandsaw' for those roughing tasks (note that neither of my thoughts are actually free-handing. . .I love jigs. . .). :)

Very cool to see your project.

Sandy.
 

kenstarr

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Pretty sure I called that just over a week ago in post #2. Nice execution!

I saw you mentioned free-handing the initial discs. I assume you're going to free-hand with the wire, not a different tool. Given your woodworking hobby (which seems more than a hobby looking at the work you did on the harp), are you planning on doing a jig like is typically used to cut discs on a bandsaw and just using the wire for that or would you make a second wire 'bandsaw' for those roughing tasks (note that neither of my thoughts are actually free-handing. . .I love jigs. . .). :)

Very cool to see your project.

Sandy.
Well... I promise I'm not a good woodworker! And uh, I didn't think of the hot wire "bandsaw" until I started cutting out the disks and the throat of the saw wasn't deep enough. Too late now. Maybe in the future I'll set up a collapsible long arm "saw".
When I was a raw apprentice electrician I worked with a guy and as I watched I thought "wow, I definitely wouldn't do it that way". It was a really good learning experience on a regular basis. Now I'm that guy! I could have made a hot wire bandsaw super easily. We'll see how this thing works out and maybe we'll all learn some handy lessons!
Ken
 

kenstarr

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Hmm. I hope I cut these oversized enough... They're just stacked here, not centered on a mandrel or anything. I suppose it might work but it's not the way I'd do it... next time.
-Ken
 

kenstarr

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Assembled the most rinky dink template for the foam cutter known to mankind! It worked great! The sides were 1/8" MDF which was a shade too thin because the hot wire started to cut it in a few areas. I opted not to run a rod through the whole thing and ju have a pin on the bottom and top. Next time I do a foam nose cone instead of cutting circles, I'll cut squares because it carves all the same. Circles were good for the router mill as there was slightly less mess. Overall, the setup was very simple and it took about 5 minutes to disassemble the jig and clean up. The router mill was more fiddley to set up and took an inconceivable amount of time to clean up but did produce a marginally better product.
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