2013 Pulsed Motor Build Off Competition Announced

[tinman]

@TK
Here is this years ruel's or motor guide line's. We have opened it up a bit,and it no longer has to be an electrical pulse.

A rotating device that turns by pulses. Those pulses are not limited to electrical pulses.
It can be gas pulses,liquid pulses,or anything that creates a pulsing force ( most the time repetitive pulses but could be limited to one pulse) that is used to rotate the device's mechanism ,rotor,flywheel ECT.
It can be big or small,and made from any material.
The wackier and most use of resources the better.

The pulse motor build off actualy started as a private comp between Russ and myself lol. But we then decided to extend it to everyone.
This will be the third build off,and we hold one every year.
This has brought out setup's the likes you have never seen,even a gravity/weight shifting pulse motor. There was also one that fired  very high voltage arcs into a wheel with ventury shaped jets cut into it.This expanded the air inside these jet's,and forced the expanding gas out of a small opening on the side of the wheel,which in turn rotated the wheel at quite a high speed.

There will be two categories, class A. Advanced. and class B. Beginners/use of resources. Russ and Brad will decide witch category you will be in, based on previous builds by yourself/ your entry video. we encourage the beginner's to use there resources. this will help you in your class. Build from junk is good!!!

All info can be found on my forum here-http://iaec.forumco.com/forum.asp?FORUM_ID=54

So- who thinks they can come up with something that hasnt been done befor,to rotate a shaft,flywheel or rotor-using pulses of some sort.

[tinman]

In reguards to safty-please guy's-play it safe.
Below is a picture of one of  my moderators on IAEC.
A magnet came loose,and this was at only 730RPM. He nearly lost sight in that eye,and spent many months with vision in one eye only. Although we see them as toys,they can be very dangerous.

[TinselKoala]

@tinman: Thanks for posting the details! I don't know if I can come up with anything "new"... without a lathe I can't work to the precision necessary to make a Warlock's Wheel PM (Marinov's Siberian Coilu) unfortunately. But maybe someone else might be interested in making one.


SAFETY IS NO ACCIDENT.   

That's a slogan from years ago that the civil aviation authority used in their safety literature. And it is right: safety must be planned in, from the beginning.

Please please please, all builders of rotating assemblies or even stationary ones using magnets: DO NOT RELY ON ADHESIVES to hold your magnets in place! Always design _structure_ that restrains your magnets physically so that they _cannot possibly_ come loose! There isn't much that is more dangerous in our home laboratories than a strong magnet out of control flying off at high speed.
Strong magnets are dangerous! We play with them casually all the time so it's easy to forget. But even a small NdBFe magnet can shatter when it hits something, and when it shatters, small bits will come spalling off at high speed, these are usually red-hot, and if one hits you in the eye... or hits your child or pet or spouse or something.... you will be sorry.

Wear safety glasses. If you wear spectacles, have your optician recommend some prescription safety glasses. I have a bifocal pair that I had made with the bottom part so that I can focus easily at "lathe" distance and the top part for distance vision. Strong shatterproof lenses. A full face shield isn't too silly in certain cases: My good looks were saved by one when a big capacitor I was working with blew up in front of me, spraying hot oil all over the place, caught on fire.

We are all really lucky, even the fellow with the shattered eyeball above. Let's not push our luck by designing in disaster. Safety is no accident.

[MileHigh]

Analyzing the efficiency of the transistor switching is not something that you normally see but it might be something for some people in the advanced group.

There are two main goals and there are trade-offs where one optimization can have a negative impact on the second optimization and vice versa.   The two optimizations are 1) to switch the transistor on and off as quickly as possible, and 2) to burn the least amount of energy through the base transistor and diode drop of the base-emitter junction in the transistor.

The reason you want to switch the transistor on and off as quickly as possible is that the transistor is burning energy through the collector-emitter junction during the switching itself.  It the transistor switches off slowly it will steal energy from the back-EMF pulse.

Let's assume that the motor is running at its high speed steady state speed.  Let's also assume that you have done a manual test of the transistor with the drive coil to determine the minimum base current to saturate the transistor relative to the resistive load of the coil.  You may or may not want to use that data.

So you have three variables to play with:  1) the number of turns in the pick-up coil which will determine the max EMF voltage, 2) the physical size and shape of the pick-up coil which will determine what the EMF waveform looks like, and 3) the value of the base resistor.  By experimenting with your scope and watching the switching carefully and also looking at the pick-up coil voltage waveform you could in theory find a maximum efficiency sweet spot for the switching at the max steady-state speed.

MileHigh

[tinman]

@TK
A Warlock's Wheel ?.
Well as you probably know,i have a lathe lol.
I also have run out of ideas for a build in this comp-although i cant enter ofcourse.