2013 Pulsed Motor Build Off Competition Announced

[TinselKoala]

There was a report a couple weeks ago where a guy was seriously injured when a magnet he was spinning fast actually came apart. It happened once and he was slightly dinged, then a few days later he did it _again_ and was hurt bad, I think he needed surgery on his hand.

So the speed limit can be exceeded, this is known already. Please stay safe, there is no point in speed for speed sake. Did I just say that? Balls to the wall, men, damn the torpedoes and full speed ahead! (but wear safety glasses anyway)

I'd like to know if unconventional power supplies and operating principles are allowed. Are these to be strictly electromagnetic PMs, or would electrostatic or even pneumatic drives also qualify? How about a gravity-driven PM? (Or rather a PM that was mechanically driven by GPE converting to KE, like a cuckoo clock)
I am being serious here.

[TinselKoala]

MH:

How about 300,000 rpm?  There are several folks that use a simple sphere neo and hit those speeds or higher.  (very dangerous of course)  The highest I have obtained is 16,000 rpm with my Jonny Davro one magnet, no bearing Bedini pulse motor. (Using the Lidmotor transformer coil)

Bill

I have to admit that I'm a bit skeptical of those reports. I think they are driving with a frequency of 300kHz and assuming synchronous rotation, but I don't know if they have any concurrently valid measurements of speed by other means.

I've been rotating a little disc magnet glued to crude axle made from a bit of wire, no precision at all, using a couple of coils driven by my function generator. I can get 5000 rpm or so, confirmed by strobotach. I'd really like to try a sphere magnet in a good solid housing, in a vacuum, with proper tachometry, just for grins.

[MileHigh]

Bill:

No spinning eggs, it's has to be a motor.  Speed just for speed's sake.  You could even watch it from behind a pillar via a big mirror.  lol

I took my inspiration for this design from a battling robot from either Robot Wars or Battlebots.  I tried to find it on YouTube but gave up.  The team took a mag wheel rim and built the robot guts inside the solid aluminum rim.  I think it fired a metal horizontal shaft back and forth.  The shaft was terminated at each end by a sharp point.

So if you can imagine that, with a bloody mag wheel rim in the boxing ring, the body of your robot is pretty much indestructible.  I don't think it's mobility was particularly good and it's weapon of the "plunging pointed stick" was not so great.

Of course those two shows are great fun just in terms in looking at the builds of the robots themselves.  The super heavyweights were scary for sure and easily had the capability to do serious harm to a person.

MileHigh

[Pirate88179]

Well my pulse motor made from a vcr head using 4 neos hit about 12,000 rpm.  Not all that fast but it sounded cool.  Would that qualify?  It even had a threaded adjustable gap between the coil and the rotor.

Battlebots are cool.  Too bad they don't allow explosives to be used.

Bill

[MileHigh]

Another cool project would be based on the beautiful direct drive turntables from the late 1970s and 1980s.  They had a tape head reading a magnetic stripe on the inside of the platter for servo speed control and a beautiful direct drive where the platter is the rotor with a magnet array, and there is a stator electromagnet array in the base.  It's all optimized for constant RPM.  I would assume there might be a micro at the heart of the thing.  However, it could be done with hard-wired logic also.

You might be able to hack into the speed control and in theory with the servo feedback there is built-in variable torque to compensate for changing loads.  Making the speed variable could be as trivial as replacing a crystal oscillator signal with a signal from a function generator.  Then if you could somehow boost the power going into the stator electromagnets but keep the same control signals you are rocking.