4 Attachment(s)
Polystyrene Cone shaped hole cutter
Got plastic drums for a floating raft hydroponics system. That required a piece of polystyrene floating on the water with holes for the net pots with the plants in them. Usually lettuce.
So as usual research as to how to make a hot wire cutter. Needed some Nichrome Wire...
Where to get it...toasters, hair driers, old irons... Wife has a hair drier....Will she notice if I remove one of the heating elements??:headshake:
Attachment 27019
After careful investigation I removed one element. :lol:
Attachment 27021
Perhaps after the cleaning the hair drier will actually work better as it will definitely blow stronger. Filter at the back was totally blocked.
Wire turned out to be 26 gauge.
Found a website where you enter gauge, length of wire, temp required and volts and amps are then calculated.
I needed 2.8V and 6 amps. I recon this is good info if you have a infantile variable power supply. I have a 12v car battery...
Then to build the little cutter to accommodate the 75mm net pots I drew one out and was going to use a 25mm broomstick as the pivot so extrapolated the angle to determine the length of the broomstick.
Attachment 27023
So how it works, I cut 25mm holes in the foam,and then power up the cutter. The broom stick fits nicely in the hole. I then just slowly rotate the broom stick and the angled wire cuts a perfect cone shaped hole in the foam.
Attachment 27024
To keep the tension on the wire once it is warm I fitted 2 elastics on the one end of the wire and pulled then tight in a piece of condute and secured with a steel pin on the other end. I cut the condute at the same angle as the wire to pull in the same direction as the wire.
To stop the wire burning the broom stick at the bottom I first fitted a 25mm washer, the same at the top a piece of scrap ali plate.
I fitted 2 wooden washers under the top support. this was in the event that I wanted to cut different sized holes. Then I only have to remove the washers.
https://youtu.be/SOdrqUfrd7k
Perhaps this explains it better.
