RCU Forums - View Single Post - Here is the dummy with another dumb question
Old 10-07-2011 | 11:20 AM
  #21  
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opjose
 
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From: Poolesville, MD
Default RE: Here is the dummy with another dumb question


ORIGINAL: Villa

Hi goirish
I have built and flown two types of pusher Canards over a period of 7-8 years, using OS46FX and AX engines and APC pusher props. An interesting point is that the engines tend to overheat while you are tuning them on the ground. It took me a while to realize that. Once I learned that feature, I replace the pusher prop with an identical ''standard'' prop and do all of the tuning. Then I put on the pusher prop and take off. I mount the fuel tank in the conventional location as close the the engine as possible, and then use a very small second tank much closer the the engine. The pluming from the muffler to the carb inlet is all in series. In this way there is never any hesitation. I like to be in the air withing 20 seconds of starting the engine to prevent overheating.
Boy I learned this the hard way too!

A friend walked up with a temperature gun after seening me battling for hours with a pusher plane.

He took a head temp reading at the glow plug close to 380 degrees... I then knew what was happening.

Tuning with a normal prop first is a very good idea.