I recently decided to try to build an RC airplane and needed a clean and effective way of cutting the foam I will be using for the plane. After some research I decided that a hot wire foam cutter would be the best solution. 

I wanted something that would be able to produce clean, even, reproducible cuts so a hand help cutter was out of the question. I ended up going with a band-saw type of design.

Step 1: Tools & Materials

Materials Used:

>2x4- x2 18" pieces & x2 15" pieces
>1x2- x3 15" piece
>Sheet of some sort of flat surface- I used 1/16th ply board

>Drywall Screws- 1-1/4" & 2-1/2"
>Adjuster Bolts- 2" (top) & 4" (bottom) + nuts
>Metal Plate Roughly 4" square + 2-1/2" Bolts (optional)
>Wire tensioner spring + Washer (Of equal outer diameter)\
>Shaft (Of inner diameter equal to above OD)
>Some sort of bead (I used a fishing lure sinker)

>Thin Steel Wire
>Power Supply


Saw (Ideally mitre saw or circular saw)
Drill (with some drill bits)

1/16" ply board? Are you sure?
Yes, why? <br> <br>It's a little thinner than ideal maybe but it's what I had around the house.
I'm sorry. I have never seen plywood thinner than 1/4&quot;--I though it was a typo.
Make me one
Will this cut thru foam core boards? If so, what thickness cuts best?
It would depend on what the outer layer is. If it is something that could be cut with hot wire then yeah it should. I'm not sure about thickenss- that would depend on wire gauge, and PSU current.
hi um would it be possible to use stainless steel wire
guitar strings are stainless steel, so yes
It's not a great idea to use galvanized wire (as shown in your photograph). Heating galvanized metal can release toxic fumes. Breathing them causes <a href="http://en.wikipedia.org/wiki/Metal_fume_fever" rel="nofollow">metal fume fever</a>. Try to get some NiChrome wire (perfect for cutting foam). Maybe a guitar string, if that's easier to come by.
Thanks for the tip but I don't think this wire gets anywhere near hot enough to release the toxic zinc oxide.
Sorry, but &quot;I don't think&quot; doesn't trump okienAZ's valid info. I won't tell you what to do, but others making hot wire cutters should rather choose a different wire.
Awesome! Been wondering how to do this for a while... Can you give a little more detail on the steel wire you used? <br> <br>many thanks
Added a picture of the wire I used.
Excellent! Now I have some work to do before Halloween season comes upon us. Thank you!

About This Instructable


80 favorites


More by spizzak: Munny Touch Mood Light and Speaker 1993 EX500 Race Bike - Complete Rebuild Valve Clearance Adjustment How-To (inline-4 motorcycle)
Add instructable to: