Monday, November 8, 2010

Why Prototype and Test?

I know that posts about motorcycles were promised. Unfortunately, my personal backlog has not had blog articles ranked near the top. Things have gotten a little easier so here is the first article on custom motorcycles.

My brother, Greg, and I have been working on a little Kawasaki bobber for some time now and it is coming along pretty well. In looking for a feature that would set it apart from the bikes of other builders we came upon the idea of creating a tank that would hold all of the electrical components including the voltage regulator, rectifier, battery, and all of the associated wiring. Greg had access to a bunch of old fire extinguishers so we picked one and got started.

The idea was to cut the extinguisher to the right length, build a bracket that would hold all three components and their wiring  then mount the bracket in the tank and then in the rigid frame. All wiring would feed out the top.

We formed the bracket up; made sure the battery fit and made mounts for the voltage regulator and rectifier. Once we could mount all of the components we went about making it perfect. Corners were rounded, welds finished and ground, the outside of the bracket sanded down in preparation for paint. We finally mounted all of the parts together and went to figure out how to mount the finished assemble and the tank and the problem became obvious. We hadn’t accounted for the tank getting smaller at the top, it wouldn’t work. No amount of bending, grinding, cutting or drilling was going to fix the thing. It was time to start over.

The second go round went quickly and we came out with a highly-functional part that met all of our acceptance criteria but it wasn’t ready for paint.

The sequence of photos shows the finished bracket and how it fits inside the tank:

Here is the finished product. You can see the first failed attempt in the background.

As a post script to this little tale we learned one even tougher lesson. It turns out the battery we worked so hard to hide isn’t actually big enough to run the bike. Maybe we should have tested that out first. Now we are looking for a battery that size with enough juice to do the job.

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