----- Original Message ----- From: Horace Heffner <[email protected]> Date: Sunday, August 16, 2009 3:19 am Subject: [Vo]:Ball Bearing motor COAM test
> We had a power outage here yesterday for a few hours. We put in a > new > radio phone system a month or so ago, and it went down with the > power. Nothing worked here - except my little experiment, which is > > battery operated. I took off the scope probes and hooked up a > couple > voltmeters and was back in business with the aid of a book light > attached to my Carhartt's bib jeans! 8^) I was able to look at > the > voltage drops across a wide range of rpms, and there was not much > difference. Max was maybe 4 V across the motor total. That was > uncertain. I was surprised to see how wacko it made the digital > voltmeters. The scope signal looks fairly smooth and narrow-ranged. > > Since the motor is a bit strange I decided today to do a quick test > > for conservation of angular momentum. I remounted the steel > bearing > motor vertically for the test, and spun it up with a Dremel tool, > and > started the power. The film says it all. No significant COAM > violation. However, as the unit rotates a bit you get a view of > the > battery and makeshift splashguard and get to see the motor run > fairly > fast. Not much compensation for watching, I know! 8^) > > http://www.youtube.com/watch?v=6OdBa8bZHl8 > > http://tinyurl.com/r7e5gu I was wondering about changing the orientation too, although I would have suggested clamping the motor vertically (instead of hanging the apparatus) to see if gravity affects the motor. Harry
