brushless motor setup / testing

To date all my E models have been been built IAW the manufacturer recommendations but i'm now I'm more involved and establishing my own set ups. I find changing motors on a base model and assembling that model in order to run and test a set up hard work .Last months RCME contained an article on someone's design using heavy duty roller slides which even I thought was a bit OTT. but more importantly i thought debris might eventually jam the slides.

I had some bits and bobs left over from a previous project so cobbled this together to prove the concept. This design used a simpler rocking structure. I can test the electrics, thrust and RPM.

What about airspeed measurement (or are you relying on the prop pitch vs rpm)?
If you did have an anenometer in the system you would also be able to measure the propeller efficiency.

Cant measure airspeed cos its a static test bed !! :woohoo:

I guess knowing the thrust relative to model weight is a good starting point.

Measuring thrust I have done it two ways. With a pusher plane on a smooth surface the nose up against our kitchen scales up against the garage door. Rough guide on thrust. With a normal aircraft on it's wheels, I attached it to my digital luggage scales using a bit of nylon string. Another guide to pulling power. Although just as something to do for info. I try different props and monitor the current drawn so it is all within specs of ESC and motor. I look for a minimum of 100 watts per lb for a warbird although I try to get much more. Civilian may need less. eg: Twin Otter. Each motor (700kv) is pushing at full throttle 600 watts and within the max amps (32a) for the motors. 1200 watts available. Plane weighs 7 1/2 lbs. With the 3 blade 11 x 7 props the Otter is happily flying at less than half throttle therefore extending flight times too.

When flying electric you get to feel it is right or your happy with performance Hence why I have so many props too.:lol: .