This project got me started on the road to understanding wiring electronics.

Also it was pleasing to finally use bits of junk to make something actually useful to make other bits of junk become something useful.

Not only can you make pretty things with it, but it can be useful with lost foam casting.

 

This youtube video might be useful in understanding electrocution <LINK>

Stuff you'll need:
- Base board
- lengths of wood
- threaded rod/ long bolt
- bunch of washers, nuts, 2x wing nuts, bolt (to be drilled)
- Nichrome wire
- cable from scrap computers
- power supply, switch, fuse
- soldering iron, heat shrink, multimeter
- spring (might not really be needed)
- glue gun for quick assembly (optional)

 

Begin with the base board. Make some measurements. Drill a hole where you want the Nichrome wire to pass through.

If using chip board, Add support blocks for the main arm to bolt to with the wing nuts. Don't rely on the chip board for strength if you drill into the edge, it'll split.

Underneath add a cross beam with a hole drilled for the bolt which will tighten the wire when done. the bolt needs a hole drill through it. I used a dremel to flaten a spot to make it easier to drill.

now collect a locking nut, another nut, and washers.Try to assemble as shown in the pics. Connect another power cable and run it so it's not in the way.

Now you can begin building the arm. The height is up to you. You want a section above the hole to have either the threaded rod, or long bolt. You could chop the head of the bolt. Cut out some access holes to help for adjusting later. Big enough for a spanner.

Find a washer that'll slide along the rod and drill 2 extra holes. one for the cable to power it, the other for a spring. then place nuts either side of the washer and get it roughly in place. Add the cable and spring.

Now you can add the nichrome wire, and test if eveything is solid. Then begin tighening it being careful.

Now sort out the 2 cables. Add switch and fuse and connect it to the power supply.
Something like 5V 2.5amps will work. More amps will be better. It all depends on the length and thickness (guage) of the nichrome wire.

Use a set-square to get the wire striaght. Have mother on speed dial and plug it in. It should heat up immediately.
Have fun! But don't die!


Ok my understanding so far is (my maths could be completely wrong):
you need voltage in order to push the current through your body.
100 - 200 mA is lethal. Even 10mA will give a nasty painful shock.
What happens is the current screws your heart and could stop it beating. It's amazing I haven't killed myself yet!

V = I (current) x R (ohms)
watts = Volts x amps (current)

so this power adaptor is 5V x 2.5A = 12.5W

 

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