049 test stand dont's

Got a Cox reed valve 049 engine going today, with a Davis head.

For a motor stand I'm using a Tatone stand with a piece of 1/8" angle 
iron on which the engine is bolted.

Don't do this, unless you want some practical education in resonances. 
At the 'bad frequency' (which was just a bit lower than what the engine 
really wanted to do) I could see the cylinder moving through a 1/4" long 
arc.

Very disconcerting.

But I could damp it out by hanging on to the engine, so I verified that 
it runs (and smells) normally for a little Diesel conversion, and I have 
the compression and mixture at a good setting to go on a plane.

Tomorrow I go flying.

Sometime soon I go get some nice thick T-bar and make a new test stand 
adapter for 049s!

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

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"Applied Control Theory for Embedded Systems" gives you just what it says.
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