Monday, March 23, 2009

Cheap 'insolution'

I think I did a nice discovery by taking an old soldering iron apart to its core.

This is a minor edit due to the fact that I just read Nopheads blog about his attempt to use a soldering iron (should have done my homework better). Off course I couldn't have expected that no one would try to use a soldering iron but by taking it apart further I found some components that are very well reuseable in a self build heater barel. This would solve the problem Nophead had with the jamming plug.

It turns out that this soldering iron is build up in the folowing order:
-steel tube that holds the tip
-Mica sheet for electrical insulation
-heatingwire (NiCr ? it seems the same as a toaster)
-another layer of Mica sheets
-outside tube of the iron

The Mica makes a very good electrical insulation wich makes it posible to place the coil nearer to the heater barel and so providing a good thermal conduction to the filament.
You can adjust the temperature gradient along the barrel by varying the pitch of the windings.

On the picture I marked the places to cut the outer tube with a plain pipe cutter like plumbers use. This iron comes from a soldering station with a regulated temperature so there is also a thermistor installed in the inner tube.
The advantage of the Mica is that you can controll it better than puty beacuse you can see what you're doing. Also , you can take it apart as often as you like.
I think cheap-ass soldering irons make a good source for heating wire, Mica sheets and if you're lucky thermistors. Altough I understand from Nopheads attempt that the type of thermistor isn't the right one.

I'm not sure if Mica is called the same in english as in dutch. So to be sure: Mica was used in stead of glas in old stoves with coles. It's yellowish, brittle and it can withstand high temperatures. I only know this from stories because this was before I was born... ;) SO if anyone knows more about the material (perhaps where to buy it...) I would like to hear.

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