Hot Wire Styrofoam Cutter?

Discussion in 'FAQs' started by Lighthorseman, Nov 2, 2003.

  1. Lighthorseman

    Lighthorseman Active Member

    I'll just bet that a Gauge member has put together a home-built hot wire styrofoam cutter. Is this a difficult project? Is it just easier to tootle down to the LHS and buy one?

    I'm asking because my wife has a very nice adjustable power-supply thingy for her stained glass soldering iron, as she needs different temperatures for different types of solder and copper foil. If I'm not mistaken, one of these also happens to make a dandy hot wire controller. Is this correct?

    Is a hot wire cutter simply a device that heats the wire by creating a short circuit?

    Please do tell!
  2. jon-monon

    jon-monon Active Member

    You need ni-chrome wire, Steve.
  3. jim currie

    jim currie Active Member

    if the thing your wife has is a resistance soldering tool will work just need ni-crome like Jon said been playing around with with one just bend wire in shape you want .
  4. Vic

    Vic Active Member

    Foam Cutter....Real Cheap

    You've probably got all of the stuff just laying around. I've built several of these things. They work just fine. Just make sure that the nichrome wire is real taut. It should go "twang" if you pluck it.

    I'll leave the dimensions and the wire routing up to you.

    STEVE:....Since the foam cutter is "dead short" I wouldn't use the wife's good heat controller....It probably doesn't have any protection as it is "geared" to the resistance of her soldering tool.
    Use an old trainset power pack instead and vary the heat with the throttle control. The worse that can happen if you set it too high is that the curcuit breaker in the powerpack will open and then reset when it cools down.

    Attached Files:

  5. billk

    billk Active Member

    The I one got (by tootling down to Michael's arts-craftsy store) uses a couple of D-cell batteries for power. Seems to work just fine.
  6. Lighthorseman

    Lighthorseman Active Member

    Thank You!

    Thanks for the tips, everyone! I'll be having a look at this... :)
  7. jon-monon

    jon-monon Active Member

    The ni-chrome wire is ratd in ohms/ft., so, the longer the wire, the less power will be required. Less power will also mean less heat. If you know the resstance of the wire, you can divide the voltage by the resistance and get the current requirement (amps).

    A 12V car battery charger rated at higher amperages should do nicely too.
  8. MasonJar

    MasonJar It's not rocket surgery

    I did one pretty much like the diagram Vic supplied. Used an old (really old) power pack, some telephone wire, and a wood frame.

    I got the nichrome wire for $2.50 at the hobby shop off the Woodland $cenic$ display - it's replacement wire for their $65 cutter.

    One thing I would suggest is that you make some sort of tensioner (is that a word?) that keep sthe wire tight. As it heats up, it tends to stretch. This is really only a problem if you wan to cut your own grades or risers, and need a smooth, flat surface.

  9. ezdays

    ezdays Out AZ way

    I am still working on my first layout and am finding that cutting with a knife is a big PITA when I want a smooth cut. I have seen somwhere that a good alternate to a hot wire cutter is an electric knife. Seems to me to be a bit easier to control and no danger of being burned. Plus, it has one end open, whereas the hot wire needs to have both ends secured to the frame.

    Has anyone used an electric knife, and if so, is it worthwhile?

  10. Vic

    Vic Active Member


    Just a couple of notes for those considering cutting foam with a hot wire.

    1. Be sure your cutting area is well ventilated. The fumes that result are toxic.:eek:

    2. Don't heat up your wire "red hot", just hot enough to cut the foam. It doesn't take much heat to cut the foam.

    3. Let the tool do the work, don't force it. The wire will break easily when hot. Experiment with the temperature...when you have the right setting it will slice right thru the foam with little or no smoke.
  11. Ray Marinaccio

    Ray Marinaccio Active Member

    Has anyone tried one of these?
    Its used for uncapping honey combs.

    Attached Files:

  12. Ray Marinaccio

    Ray Marinaccio Active Member

    This is something I built to cut the roadbed contour after the track was laid.
    I bent a paperclip for the cutting tool.
    The length of the wire leading to the cutting head will determine how hot it gets.
    I would use the nichrome wire tool described earlier in the thread for large areas.

    Attached Files:

    • hw1.jpg
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  13. jon-monon

    jon-monon Active Member

    Looks like your tool did a great job, Ray!
  14. TinGoat

    TinGoat Ignorant know it all

    Hot wire foam cutter

    Hi Steve,

    If you are still on the OCMODS yahoo group, take a look at: Hot Wire Foam Cutter.

    I'd just cut 'n paste it here, but that scrambles the diagrams and I can't add a .txt file as an attachment.

    If anyone else is interested, then I could send it to you via e-mail. Just PM me to let me know.
  15. TinGoat

    TinGoat Ignorant know it all

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