I tried this method and it works, but probably only good for measuring relative thrust between battery/prop combinations.

-Assemble the plane and tie a loop of string around the tail. Hang it vertically from a digital fish scale.

-Zero the scale, making the weight of the plane ZERO.

-Run the motor at full speed and record the thrust from the scale.

The plane may tend to twist, but a helper can steady it without pulling down on the plane (like the old butcher used to do when weighing meat for your Mom)

I tried it and it seems to show what prop has the best thrust on a certain battery/motor combination.

I wouldn't want to try it on something like George and Dave's TU-4 Bull!

Beats my method of seeing wich blows more air in the face.

John

Great idea... my dad has been bugging me to try to firgure out how to do this. I was going to build a system to hold the motor by itself but this beats that. Thanks man!

I just usea standard cheapo fishing scale from wal-mart.Tie one to a stake in the ground(or now my building bench in my shop.The other end gets a loop of strink that goes around the tail.I then take out the slack and push throttle to wide open look at what the weight pull reads At the same time I look at what my WATT Meter says for staic amp draw.This system works mint and has never let me down.Have fun,stefanP

I basically use StefanP's method. I bought a cheap pull string scale from hometrainingtools.com for $3.25. I tie fishing line around the tail and hold the scale while I increase the throttle. Seems to work pretty good. Hoping to get a whattmeter for xmas.