Too Busy For Words - the PaulWay Blog

A quick search around my various machines shows I haven't actually blogged about getting the motorbike running (sort of) and showing it off (sort of) at the Canberra Electric Vehicle Festival 2010. This post attempts to correct that.

You will recall in our last thrilling episode, I had attempted to get the motor running and failed. Now, with only a week to ... what's that? Oh, yes. Then, with only a week to go, I wanted to be able to show off the bike running at the Festival - or at least the back wheel turning under its own power. This meant pulling apart some of my connections on my mock-up box and testing things out one by one - a time-honoured debugging technique.

I'll spare you the whole exhausting detail. Fixing problems is a matter of connecting everything up, applying power to the Kelly controller, carefully observing the little flashing red light and looking up the error codes in the booklet. What I learnt in the process was:

• My 24 volt power regulator does a splendid job of blocking any voltage under 24 volts. Remove this if you want to just run it off 12V (which the controller can take).
• The controller uses the voltage returned from the potentiometers. So you need maximum resistance for low speed and zero resistance for maximum speed. I had this the wrong way around.
• When freewheeling the motor is powerful enough to drag the stator up faster than the controller expects. This then causes the controller to try to slow down the motor, before speeding it up again and so forth. This makes the motor jerk around much like a stepper motor - which in fact it is. This is perfectly normal when running the motor with no load.
• It's tempting to use thickish speaker cable as power wire. It isn't really designed for this. If you smell hot insulation, turn the power off.

Unfortunately what I didn't work on in that week before the festival was actually putting it all together in a neat, safe way. The EV Festival coincideded with Software Freedom Day, the Turning Wave Festival, and at least one other all day event that I'd been invited to go to; I was trying to help arrange the first, arranging to go to part of the second, and steadfastly refusing anything else. On the Friday night I looked at the mess of cables and connectors, the possibility of something going horribly wrong, and even just the possibility that I would be making EV building look like a boffins-only activity and gave up.

Two weeks before the show I also realised that it would be much better looking if it had panels on it. I'd taken the front and side fairing off because of damage in the accident that got me the bike in the first place. Naturally, I should have ordered the panels two weeks before that to get them in time. So I ended up showing off a bike that was more or less frame, wheels, seat and motor, along with the controller and a cardboard mock-up of the battery.

So on the Saturday I wheeled the bike onto the trailer, drove it down to the fair, helped set up the crash barriers for the driving course, set the bike up, walked around talking to a few people and looking at the other exhibitors, heard about pouch batteries, and generally talked more or less non-stop about the bike. I had printed up some helpful fliers with a brief run-down of the components, and they came in handy. Then I packed the bike up, drove it back home, unpacked it, and drove down to Gundagai for the Turning Wave festival.

Audience reaction was mostly positive. A few people told me it had to make noise, and I was glad I had my ready response: plans to build a box linked to the throttle that can make any sound I want: sports bike, Harley Davidson, V8 supercar, jet fighter, Millenium Falcon, TARDIS, Shepard-Risset Glissando, etc. Most people liked the idea of it costing around $10,000 all up - comparable with a modern sports bike. One boy felt the motor controller and asked "is this the battery?", to which I had to sadly reply that it would be lovely if it was but the real battery was much larger. No-one spoke against it - if they didn't like it they moved on, or weren't there.

So overall it was a pretty good experience. It strengthens my desire to have the bike working by the end of the year, and to demonstrate it at the next festival.