Ed Klepeis wrote:

Dear Paul
      Looking at your eng dyno I have some questions. !. how is the long shaft connected to the eng flexcoupling,bolted flange,etc 2. On the other end what is mounted to take the reading
gauge,meter,etc and where can you get it. I was thinking of making something like this to take to air shows to show people whats on the market and who's making it. Any ideas or offers vendors out
there let's hear it.
                                                                                                                                                               Regards
                                                                                                                                                                   Ed
                                                                                                                                                 techwelding@comcast.net

Flex coupling? We don't need no stinking flex coupling!!!

I don't follow you Ed. Are you talking about a large garage door spring to measure
static thrust?  If so the dyno needs to be mounted on wheels. You calibrate
the spring by hanging it from the ceiling and using weights to measure the deflection.
It comes out to some think like 100 pounds per inch of deflection. Then all you need
to do is measure the spring with the engine off and again when it is generating
max static thrust. Don't optimize the prop or the engine for static thrust as that
can be dangerous. Some guy did that with a Suzuki engine and killed him self.
Maybe you are worried about the shaft twisting the spring. Does not happen.
The shaft only moves several degrees and that's it.

That is a small part of the dyno. The other part is the bathroom scale
to measure the torque. You might think a bathroom scale a bit crude but
the fact of the matter it makes an excellent torque sensor with high resolution
and sensitivity. Does this answer your question? Perhaps a little sketch
would make it more clear for me.

Here is another drawing off the web site. You need one of these Ed. Would help
with your Soob work. You could charge those Soob wienees for dyno time :)

BTW don't forget to use a pick up truck  steering damper opposite the bathroom scale
beam to damp out the torsional vibrations. You will find that out right
away when you start to use it.

Paul Lamar

BTW here are a couple of dyno pictures. The first is Everett Hatch's dyno in Oregon
at his shop. Lots of stuff piled around it so it is not a good picture.
Where I got the idea in the first place. The flow straightener turned 
out to be not necessary.

The second picture is what Power Sport showed up with around 1999 or 2000 at OSH
I am still looking for a better picture on this. I suspect it is the same dyno.


Paul Lamar
 
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