[Payload] Polystyrene (EPS) cutter

Hot wire, or Nichrome wire, is a very cool toy. Also potentially dangerous, but that shouldn’t stop anyone having a good time. It’s simple, wire it up to something that can provide a good DC current, from 3 to 20V’s to be safe, get a good resistance (i got 7ohms/meter), and order one up at ebay (search: Nichrome wire). It cost me around $4 for 2 meters of the stuff.
It works like this: it has a low resistance, so hook it up directly to a power source and it will heat up. Or, alternatively, your battery/adapter will heat (blow) up, which also, can be both dangerous and fun.

Skill level required: none at all. Be sensible, though.

Video with simple proof-of-simplicity example

*sorry i am using a different video, but you get the point probably*


In the video, just 3.7 V’s was applied with (measured) 2.5A current. The smaller the wire, the higher the current, so don’t get the wire too small.

Sizing it up

A 50cm hotwire!

What you see in the image above, is a hotwire running over a steel thingy i had lieing around. It’s a good 50cm, ideal for cutting anything. I just wired it up directly to two LiPo’s (in series) having a total of 8V. LiPo’s have a pretty low internal resistance, so that will go fine, as long as you have the nichrome wire in place. I have nichrome wire that has 7 ohms per meter. I can not suggest you get a lower resistance than that, or the lipo might blow up. Anyway, i loved it, it cuts through EPS like butter.

Applying it for nylon cord cutdown

That’s easy. Just connect it to a simple relais (or some strong minimum 2A MOSFET/transistors). Just let any processor flick a switch and the nichrome wire will be glowing hot, cutting through anything nonmetallic (until it cuts itself).

Disclaimer: i advise you not to try this at home.

Tim Zaman

MSc Biorobotics. Specialization in computer vision and deep learning. Works at NVIDIA.

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1 Response

  1. September 16, 2011

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