Author Topic: Electric heater for hot air engine?  (Read 10053 times)

Offline vtsteam

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Re: Electric heater for hot air engine?
« Reply #25 on: March 19, 2025, 09:53:15 AM »
This is how they will fit together for a trial. I can't run it yet because of all the moisture in the plaster still, even though it's cured. It still has to dry thoroughly.

Variable power supply is going to probably be running about 15 volts, I'm guessing. It's a constant current type and max available is 10 amps. I'm thinking somewhere around 150 watts should be enough, but as yet, it's unknown.


 
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline vtsteam

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Re: Electric heater for hot air engine?
« Reply #26 on: March 22, 2025, 07:00:07 PM »
Well it took 4 days to dry sufficiently to do a test on the coil. The plaster felt relatively dry finally and room temperature (not cool to the touch from evaporation).

I did a number of graduated tests of the heater starting at 30 watts, using the variable power supply. Temps were kept below 200 to start with in order to dry out any remaining moisture.

There was also some odor from a small amount of smoke as the tape, which held the original coil in place, and the small residue of release agent vaseline burned off. I did this outside on the porch for ventilation. All went well and the heater was a success when tested up to 90 watts, at 12 volts.

This was below the temperature where the stainless wire glows. I.believe that would be somewhere around 150 watts, as estimated earlier with wire tests. I'm really happy with the result, and I was able to run my No. 83 hot air engine on the heate in a test. (see that thread here: https://www.madmodder.net/index.php/topic,13865 ).  :ddb: :ddb: :ddb:  :dremel:
« Last Edit: March 22, 2025, 10:08:26 PM by vtsteam »
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg