Author Topic: a vacuum engine is pure joy to watch...  (Read 1444 times)

Offline Zephyrin

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a vacuum engine is pure joy to watch...
« on: April 06, 2018, 09:56:07 AM »
A vacuum engine is pure joy to watch...
but we are allowed to check what they are able to drive !

The engine under test is a poppin lookalike with modified dimensions throughout, with a thin valve.
My engine managed to drive an little electric generator with its led, (a simple electric engine actually); but it was an extreme feat...
My engine reaches 1200 rpm unloaded, and about 700 rpm with the load.
The electric power returned is of course very small, in the 10 mW range !
the choice of the belt was not simple, as it introduces a huge resistance in its own.
 
[youtube1]https://www.youtube.com/watch?v=Coi3t3K_HNE[/youtube1]

I had to shorten the admission, since contrary to what I was expecting, closing earlier the intake valve was found to increase the power, the engine becoming then harder to launch (and much noisier) because of the higher depression, but it seemed clear that the driving force was increased thus. The setting of the cam, usually not crucial for demo runs, seemed important for this test.

In addition, while preheating my engine with the hot air gun, the hot air stream was sufficient to drive the engine ! Yes, no more flame swallowing ! 

[youtube1]https://www.youtube.com/watch?v=zz8zlTd45Uk[/youtube1]


Offline Perry

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Re: a vacuum engine is pure joy to watch...
« Reply #1 on: April 06, 2018, 10:33:11 AM »
Thanks for videos Zephyrin, it is always fun to do experiments with those engines.

Offline tangler

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Re: a vacuum engine is pure joy to watch...
« Reply #2 on: April 06, 2018, 10:58:45 AM »
Zephyrin,

Interesting stuff, thanks.  Some good tips there, I'm certainly going to have a go at pre -heating with the paint stripper gun.

Cheers,

Rod

Offline Brian Rupnow

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Re: a vacuum engine is pure joy to watch...
« Reply #3 on: April 06, 2018, 03:04:12 PM »
I agree--total fun.---Brian

 

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