Attention Makers: Start Making Your Own Hot Wire Foam Cutter Today

idbruceidbruce Posts: 6,134
edited 2020-08-24 - 17:01:40 in General Discussion
Hello Everyone

I am sure that some of you are aware of the new product line that I have started on, and in case you are not, here is a link to one of my threads where the product line can be seen:

Basically it is a collection of (4) Hot Wire Foam Cutting Bows.

Hot wire foam cutters will be my topic for the day, because I have something that I want to share. These cutters can be used for a variety of different purposes, making molds for metal casting, protecting shipments, creating sculptures, making models, dressing up your Parallax robots, etc... Normally I would not share the following information, because it could lead to a loss of potential sales, but I am getting older and kinder :) and this is an electronic forum, with a large robotic base, and some of you may be interested in this subject. This information can also be useful for CNC builds.

Power supplies are a major issue when it comes to hot wire foam cutters. You want your power supply to be just right. While scouring the internet, I was unable to find a good calculator for determining my power requirements, for my new product line, so I decided to make my own, and that is what I am going to share with you.

During my research of hot wire foam cutters, I had found several different powering schemes, with some of them being very costly, while others were time consuming or unsafe. I am certainly not saying that what I propose here is the safest, but it just may work for you, in building a new cutter.

I am fairly certain that perhaps 99.99% of the worlds population probably have unused AC adapters lying around, and of course this projection includes you. :) From my research it appears that several people and even companies have turned to the AC adapter for powering their hot wire foam cutters, and that is exactly what I intend to do also, because they are plentiful and inexpensive, as well as being shelf ready :) Laptop power supplies and other AC adapters are now my best friends :)

In my case, I designed my bow sizes according to what was pretty much available in the marketplace, so I have to match power supplies to my bow sizes, but in your case, being makers and certainly having a few adapters lying around, you can design your hot wire foam cutter around a power supply that you may already have :) So you have a few adapters.... Right? Okay, well I designed this MFC application, based upon common wire sizes and desired temperatures, which is basically a caculator for designing the main setup for a hot wire foam cutter, which is the power supply and the wire. By toying around with this calculator, altering the wire gauge and length, I am fairly certain that most of you could come up with a workable setup for an adapter that is just lying in a junk drawer.

I am not going to go on and on about this, but if you want to take a peek, I have included a pic of the app, as well as a zipped file which contains the app. It is a Windows application, which was built and runs on Windows 7.0.

Get off the couch, build a cutter, cut some foam, and add spoilers to your Parallax robots :)

EDIT: Please note that in order to make use of this calculator, you will need a power supply that is at least capable of supplying 1.61 Amperes.
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  • I'd like to see your version of a CNC foam cutter. Here's the foam cutter I made last year. I used it to make amas for one of my pedal boats.


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  • Rich

    I see you did not need my calculator :) Very nice!

    Do you ever have any problems with the power supply?

    I once read a paper from one of the colleges, where the professor designed and built a very unique CNC machine cutting huge blocks of foam. I tried to find a bookmark, but I must not have saved it. I briefly contemplated making one to cut foam for packaging my hot wire bows, but figured my time was better spent doing other things. :)
  • Here is table top foam cutter that I made a while ago. I use this one for making my sand casting patterns. It uses a different power supply scheme. This one uses a step down tranformer on the mains and control is provided by a dimmer.
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  • idbruce wrote: »

    I see you did not need my calculator :) Very nice!

    Do you ever have any problems with the power supply?

    Thanks, I had found an online calculator to determine wire size, length and volts/current. The power supply has worked okay for the few times I have used it. It is from an old IBM laptop.

  • kwinnkwinn Posts: 8,595
    edited 2020-08-25 - 01:51:10
    W9GFO wrote: »
    I'd like to see your version of a CNC foam cutter. Here's the foam cutter I made last year. I used it to make amas for one of my pedal boats.

    Those amas (I'm assuming that's what those two boat shaped items on the table are called) look great. Now that I am semi-retired and running a small marina I have been thinking about building a paddle boat/water bicycle using foam pontoons along the line of what is in your pictures. Would you mind sharing the dimensions and weight capacity of them?

    EDIT Any hints and suggestions would be greatly appreciated.
  • As a side note, here is a link to a YouTube video , which shows how to use Nichrome to make an Acrylic bender. I would say that my calculator could also be used to determine the power supply for making one of these, but in this case, I would imagine that you want the wire closer to an 800 F temperature, as compared to a 600 F temperature for making a foam cutter.
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