Wednesday, May 27, 2009

Test Drive!

I use that term loosely, but I did sit on the bike while it moved under its own power. This photo really captures my excitement. Honestly, the first run was somewhat of a disappointment, with the bike's performance being more sluggish than I expected. That can easily be fixed by changed the current limit in the controller. The controller is capable of delivering 300 Amps, but I have it dialed back to 120 Amps right now. There were also a number of other small issues: the chain tension was too slack, causing a lot of noise; the speedometer was not working (broken cable), and the controller kept cutting out. I believe this last problem can be fixed by changing the controller's low voltage set point.

It's been almost two weeks since the test drive, and I've made no progress on the bike since then. I hope to accomplish more this weekend and get motivated again.

Back in Business

This picture shows my new battery tray fitted on the bike. Just behind the side tray is the motor controller, which did fit nicely below the motor. I had to make a few new cables, due to their lengths changing with this layout. Overall, I think it was a good decision to go ahead with this redesign. The ground clearance is now similar to the stock bike and will not be something additional I have to worry about when riding.

Friday, May 8, 2009

Back to the Drawing Board

Last weekend, I mounted the rear tire back on its wheel, and so for the first time I was able to drop the bike off its centerstand to test the ground clearance (or lack thereof) of the battery tray. It doesn't look good. On the centerstand, the bike has about 5 inches of ground clearance. After dropping the centerstand, the bike's weight compresses the rear suspension, then I sat on the seat with my 180 lbs. The result is about 1-1.5" of clearance. That's a no-go in my book.
So... a little rearranging is in order.

The battery below the motor has got to move. I'm going to swap it with the motor controller. The battery will stick out further than the comtroller, but i don't think it will inhibit the function of the bike. Then the stack of 4 batteries in the front can all be moved up about 2.25 inches.

Sunday, May 3, 2009

Minty Fresh Power Supply

I put together a small 5 Volt power supply for the ammeter in my instrument gauges. It also supplies 12 Volts to the temperature sensor. The voltage regulator requires a heatsink, and I used a scrap of Al. plate. Everything is housed in an Altoids tin for some environmental protection.

With this power supply and the other electrics wired on the bike, the gauges are ready to go into the bike...

And I'll be damned, they work!!! The red display is the battery pack voltage, and the green display shows the amount of current flowing through the pack. The cool thing is that these work in real time, so when you twist the throttle, the current goes up and the voltage drops. Very cool.