UFO politics Keeps his word 12-12 12 Let the games begin.......

[TinselKoala]

Threw some wraps at 9000 RPM, did he? I see that on the previous page he says "the motor can take it" when talking about boosting input voltage and RPM. Perhaps that was a bit premature. Is there nobody around over there who played with slot car racing as an adolescent? I know nobody listens to me, but surely there is is someone else who has experience rewinding motors for higher torque and RPM who could have suggested that they epoxy the exposed wraps at the armature ends.
I wonder why he thinks "high temperature" epoxy is needed. I thought his motors were supposed to stay cool.  Regardless, ordinary quick-curing epoxy properly applied will solve this issue, and it doesn't need vacuum impregnation or any other fancy treatment.... just use a stiff disposable brush to work it in well (and quickly) where the wire is exposed above and below the segments. And..... yes, dynamic balancing will also help prevent throwing wraps.
It's a lot easier to prevent this from happening, than it is to fix it after it happens.

[hoptoad]

snip..... Is there nobody around over there who played with slot car racing as an adolescent?
snip...

Ahh.... ScaleXtric .... now them were the days..... KneeDeep

Many's the curve taken too quickly, with awesome high speed exits and catastrophic crashes. Almost makes a grand prix look tame!

Cheers

[poynt99]

@99: That is interesting. Lewin was trying to make a point to his students, and I'm quite sure he's given that same lecture every year for many years. What exactly is he doing wrong, and how would you explain his results? He might like to know where he's going wrong, himself.

This should be discussed in its own topic, but basically, Lewin is mixing and confusing measured electric field and measured potential difference. He is only and always measuring the electric field in his experiment, yet he is discussing and calculating potential differences in the circuit on the chalk board. He has not measured any potential differences on the circuit, because his measurement leads are not decoupled from the experiment; they are in fact part of the experiment. Lewin has also left out the fact that there are two other "components" in his circuit, for which he has not accounted for. These of course are the two pieces of wire between the resistors, where of course the circuit emf is induced.

There have been many other tests and articles written about this experiment, and thus far I have only seen folks making the same errors (and other errors) as Lewin is.

Further, how do you explain Tinman's result where his two inline ammeters read differently?

I'd love to be able to comment on tinman's circuit and results, but without a detailed circuit diagram, this is near impossible to do with any certainty. It behooves folks that are making such videos and asking for comment, to post a good diagram of their complete setup. Sorry. 

[tinman]

Here is my prony brake setup($100.00 later lol)
It would seem i have an overunity motor that is an off the shelf motor and very tired after a hard life.
http://www.youtube.com/watch?v=iLo5wXLAopc

The words look like crap after i uploaded to youtube,so redoing a version 2 with clearer words i hope.

[tinman]

This should be discussed in its own topic, but basically, Lewin is mixing and confusing measured electric field and measured potential difference. He is only and always measuring the electric field in his experiment, yet he is discussing and calculating potential differences in the circuit on the chalk board. He has not measured any potential differences on the circuit, because his measurement leads are not decoupled from the experiment; they are in fact part of the experiment. Lewin has also left out the fact that there are two other "components" in his circuit, for which he has not accounted for. These of course are the two pieces of wire between the resistors, where of course the circuit emf is induced.

There have been many other tests and articles written about this experiment, and thus far I have only seen folks making the same errors (and other errors) as Lewin is.
I'd love to be able to comment on tinman's circuit and results, but without a detailed circuit diagram, this is near impossible to do with any certainty. It behooves folks that are making such videos and asking for comment, to post a good diagram of their complete setup. Sorry. 

Hi poynt99
Yes i must get into the habbit of posting scematics with my circuits.
I will have the scematic in my next video about the circuit-trying to do many things at once here lol.
One thing has been worked out,after my big over sight that the square wave on the wave generator  dose not remain a 50/50% cycle in the higher frequencies-cheap circuit.
But there remains the problem of both potentials going negative in the higher frequencies-when one should remain positive?
Anyway,we will get it sorted.