Monday, November 2, 2009

Live from Chicago: SMMA Fall 2009 Technical Conference

Here goes my first-ever attempt to use the blog in semi-real-time.

This week, I am in Chicago for the SMMA Fall 2009 Technical Conference.

The SMMA is "The Motor and Motion Assocation." (The 'S' is silent.) Actually it used to stand for the Small Motor Manufacturer's Association. I wonder if I can get it changed to the "Scooter Motor Manufacturer's Association." Probably not. But anyway, you can find more information on the SMMA, which serves as the trade association for the electric motor and motion control industries, here:

I am participating in the conference thanks to support from the Electric Motor Education & Research Foundation (EMERF) which, as the name might suggest, is right up my alley. This foundation supports and promotes academic, pre-commercial electric motor R&D, as well as educational initiatives in the field of electric motors. More information is available here:

This all has to do with the BWD Scooter project. Since we had the completely original, not ripped-off at all idea of making brushless hub motors for a kick scooter, I made a contact at Proto Laminations who is also a member of the SMMA/EMERF. Having now actually made brushless hub motors for a scooter, I am going to present it, or, I guess, present the Summer Engineering Workshop and its fleet (yes, fleet now) of vehicles. Of course, the scooter is the only one that's in any way portable:

I did say "in any way."

And since it is generally not acceptable to ship/check/carry batteries that you made yourself, the A123 pack has to stay at home. But cordless drills (and their batteries) are totally fine:

All Tech men carry batteries...and cordless drills.

Ok TSA? So back off. Or don't:

Not surprising.

Actually, the trip out went smoothly. Actually, very smoothly. Actually, it was the single most coordinated thing I have ever seen at an airport. A full 50 minutes before the scheduled departure time, we were told to board the aircraft as quickly as possible because they were going to try to beat a storm. ~40 people got on and sat down, the jets spooled up, and we did a rolling takeoff 20 minutes early. Amazing. I honestly don't see what all the complaining is about air travel...

As for the scooter, it survived. Or wait, did it!? Why does the rear motor feel like it's got Jello in it? This is usually a sign of a phase-to-phase short, which, if you've ever shorted the leads on a PM motor, you know is electronic braking. Well, this was a scary few minutes of wondering if the phase windings somehow shorted during transport. But the problem was a lot simpler apparently:


Well, actually, I have no idea what the problem was. But I know what the solution was:

  1. Remove strain relief zip-tie.
  2. Replace strain relief zip-tie.
Problem solved. I don't really want to know what is going on. At least it's not inside the motor. I just have to not mess with it for the next three days. Did I mention that I hate live demos? This is why I obsessively video tape everything while it's working. And why I brought a soldering iron...just in case. Also, the non-functional switch broke:


But since it was non-functional, I guess it's okay.

Anyway, tomorrow I am taking an early-morning brushless motor control course where I might learn just how wrongly I've been doing it. So sleep may be in order. My presentation is on Wednesday, and I will post the slides right after. (But by now, you probably know what to expect.) And, of course, I will get to see all the other demos and presentations. Pictures and updates to come.

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