Foam cutting with your charger

by hans | July 31, 2012 | (25) Posted in Tips


This is a quick tip. I've read many tutorials on the web about how to create power supplies for foam cutting. Using ATX power supplies or building your own with heat control from basic electronic parts.

Most of us already have a charger. The Turnigy accucel-6 chargers (and many other programmable chargers) don't have a program for foam cutting like the icharger products but they can do the same. 

The power supply connection

First get the correct wire that will melt foam. What you need is nichrome wire, the finer the better (as long as it holds up). You can use other types of wire but they won't work as good as nichrome wire.

The easiest way to get your charger leads on that wire is to use crocodile type connectors. In fact the accucel 6 charger comes with 2 sets. 1 for input (keep those for charging from battery terminals) and 1 for output. That one I've never used so far. I just replaced the yellow connector with two plugs I bought at the LHS. 

I used some 14 awg wire from hobbyking in between (it's cheap an very flexible). You'll need to have at least 1m each to work on a 1m50 wing span. You need some extra to be able to work with the wires freely.

The construction

It's important to have enough tension on the wire. Otherwise your cut won't be straight. The 2 most common systems for foam cutting are the bow and the fixed point table setup. 

For a bow you need 3 pieces of wood and 2 pivoting points configured as a H. On top goes a spring or rubber forcing the 2 sides together. Below goes the nichrome wire for cutting. 

An alternative is the fixed point table setup. For this you need to have a fixed point on a table where the cutting wire is connected on. On the other side you can put a handle to keep tension on the wire yourself. You can touch all the wire except for the part that is between the connectors.

Start melting some foam

Connect this up with your charger and select the NiCd CHARGE program. You can select the current before you press start. How much current you need depends on the length of your wire. 2A is a good point to start with. The wire should be glowing just a little bit. Don't have it glowing up hot red or it will burn too fast through the foam. Try it out on some leftovers. Remember to always keep tension on the wire while cutting so that it goes straight.

For some reason my charger dropped from 10V to 0V 2 times when I started and only then gives 10V continuously. Not sure if this is related to my setup or this can be programmed or not. Let me know if someone has a solution for this. If the wire gets disconnected you'll get a connection error on the charger. 

For the profile you can use a guide on one side. I tried with balsa today but it's better to have harder wood or metal or plastic that doesn't melt too fast. The balsa was burning if I got stuck. Also make sure it's smooth so you don't get blocked by the template. It should all be done in one smooth movement.

Good luck with the cutting!


Nonamerc on September 2, 2012
Thank you hans! I just finished mine using 3mm nichrome wire. I made it one metre long so I can cut my new flying wing! Thank you very much!!
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DejaD on August 1, 2012
That is a great idea! I never even considered to try the charger, gonna have to give it a go. Nice thinking outside the box!
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Nonamerc on August 1, 2012
Good idea!!!! Rated 5 starz
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Gersio on August 7, 2012
I do have a question.
How many cells did you used to make the setup of the charger?
I do not have one Triton but I can set the amount of cells and how many Amps on the charge.
Thanks a lot for the tip.
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hans on August 14, 2012
Not sure about the amount of cells. Mine was working at 10-12V at 2A.
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hans on August 1, 2012
thanks for the feedback guys!
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InComing RC on August 1, 2012
Great idea, I have to try this! Do you think you could damage the charger?
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hans on August 2, 2012
It should be safe (at least with this accucel 6 and the blue look a likes (not sure what was first). If you loose the connection it will shut off by itself with a warning on the display. Same for reverse polarity (not really applicable here).

You can't do this with the lipo/life program though since that will also perform a check on the battery and fail on that check if you only have a wire in between. The wire acts like a resistor. Comparable with the internal resistance of batteries or powering a light bulb.

I haven't tried the nimh program yet. Also I haven't checked the programmable options of this charger. It's possible that some setting prevents the voltage drops I have in the beginning.
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RedBaron1 on March 31, 2013
Another means to the same end is to use a 12V car (full-size, that you ride in type) charger like many of us have in our garage. I've had good results on the 10amp setting.
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Runorfly on January 28, 2016
Thank you very much for your post, it all sounds so great and wonderful to me. I use iCharger 206V as I build my aircraft, this is how it goes:
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Foam cutting with your charger