[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*

http://www.youtube.com/watch?v=q6oU2e5zxLA

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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