Ron's rotor is not only very heavy but also very fast!

"Full speed is 36000 rpm"

Sorry R I had'ta 

Steven

Quote from: aether22 on May 31, 2008, 09:00:21 PM
...I am not aware of any way anyone can measure strain of steel as if it were quartz.

Strain gauge... check here: http://www.sensorland.com/HowPage008.html - you just apply a strain gauge to the surface of the shaft. It's the same principle as is used to apply strain sensors to the girders in bridges, for example.

Quote from: aether22 on May 31, 2008, 09:00:21 PM
...having you agree with me makes me feel all dirty...

Sorry 

Quote from: OUman on May 31, 2008, 09:59:21 PM
Strain gauge... check here: http://www.sensorland.com/HowPage008.html - you just apply a strain gauge to the surface of the shaft. It's the same principle as is used to apply strain sensors to the girders in bridges, for example.

Sorry 

I managed to find prices, they seem to be $800-$1000 at the lower end although it is far easier to find them than find prices so it is possible there are cheaper but it seems out of my price range especially when there are so many other better ways to isolate the effect.

So since I guess the odds of you ponying up $700+ cash are about as good a snow flakes chances in hell we may as well drop the torque sensor subject.

QuoteThane seems to on the right track with cutting his mot cores down to half and now even less...
Ron

I_ROC,

THE 1/4 MOTS DON'T WORK AS WELL AS THE I/2 MOTS.

LARRY IF YOU ARE TALKING ABOUT THE SPLIT- PHASE MOTOR - I MUCH PREFER (AND SUGGEST) A DRIVE SHAFT WITH THREADED ENDS BECAUSE ROTORS CAN COME OFF SOMETIMES AS WELL WHICH IS MESSY.

Thane

Quote from: CRANKYpants on May 31, 2008, 06:29:45 PM
STATOR CURRENT IS AN EXTREMELY GOOD INDICATOR OF SHAFT TORQUE

It's an "extremely good indicator" only if you've characterized your motor so that you known in advance of your experiment how the current and the torque are related for your specific motor. Otherwise it's just a rough guide.

Quote from: CRANKYpants on May 31, 2008, 06:29:45 PM
ACTUAL NUMBERS MEAN DIDDLY SQUAT AND ONLY NEED TO SHOW IF THE COIL IS DECELERATING TO PRIME MOVER OR ACCELERATING IT UNDER LOAD

If all you need to show is whether it's accelerating or decelerating, you can get that from the tachometer. But that tells you nothing about power. What's important is power.

Quote from: CRANKYpants on May 31, 2008, 06:29:45 PM
INCREASED STATOR CURRENT = COUNTER TORQUE = DECELERATION
DECREASED STATOR CURRENT = COMPLIMENTARY TORQUE = ACCELERATION

Yes, that's right, see the graph below, which I think you must have missed the first time I posted it.
So what?!