The end of the build was a rollercoaster of accomplishments, setbacks and workarounds. We finished the canopy, worked out the turning mechanism, and with one day to the race, there was still a lot to do when catastrophe struck.
Steering
All of my literal machinations over steering mostly failed, unless we made no left turns. I tried out what's basically go-kart steering. It's a long rod that is bent at the end so an arm sweeps back and forth, turning the front wheels. But this would only work if I could secure the other end of the steering rod.
I tried capturing the rod with eye bolts but that reduced the travel of the control arm too much. I then tried making a bracket, instead of using eye bolts. That worked better but i could only get it to steer straight or to the right. That wouldn't work. There are definitely left turns in the race, like right at the beginning.
After several hours of trying, I realized that I needed to pin the other end of the steering rod to get the leverage we needed. We used a universal joint to make the end of the steering column rotate at an angle, bolted the new end to the frame and added a slotted swing arm that linked back to the tie rods. I've never machined so many parts in so short a time.
The last steering issue was the location of the steering wheel. A normal sized wheel got in the way of my knees when pedaling, so we went with a joystick fashioned out of some leftover aluminum bar.
Propulsion
Hooking the pedals up to the Hyperdrive proved to be very difficult. I discovered that the tolerances of Chinese parts are wide and varied and it's a crap shoot as to what you get. For example, the freewheel was locked to a shaft that was supposed to sit on 1/2 inch bearings but the diameters varied wildly from shaft to shaft. Usually, the shaft will be exactly the stated diameter or just under (+.000, -.005 inches). But the shafts we got went from .003 over to as much as .007 under. It doesn't sound like much, but a .503 diameter shaft will never fit in a .500 hole and a .493 diameter will rattle around. We ordered shafts three different times before we had enough at the right size and even then, we still somehow ended up one short.
The freewheel shaft attaches to the Hyperdrive with a pair of universal joints. I bought joints that were advertised as 1/2 inch, but they turned out to be 12mm or .027 inches smaller than we expected. We didn't have time to order new ones. Instead, we had to widen all the holes in the joints. The material was too hard for drilling, so we had to use an end mill to cut through it. All this took time that we didn't have.
Brakes
While I was dealing with mating American and Chinese parts, team members worked on running and installing the brake lines. I made the brake handle to look like the hyperspace jump lever. Then I made a little bracket to insert the other ends of the brake lines (in front of the handle).
Lowell Makes' Bike Shop Technical Advisor, Steve, swooped in like a superhero and finished the job! He not only hooked up the brakes, but he also ran the derailleur lines on the co-pilot side including ingeniously using a bike rear deflector bracket as a cable stop.
Flotation
Let's not forget this beast also needs to float! We were gifted a giant block of foam from one of the other builders. The block floated in from the harbor and beached itself along a bike trail. He came across it while hiking and snagged it for us. Thanks, Matt!
Before we could figure out how much foam to use, we needed to weigh the Falcon. After confirming online that this would work, I put a scale under each wheel. Without the canopy, the empty weight of the Falcon was 180 lbs! One of my primary goals was make it as light as possible. Of course, then you have to add in the pilots and the canopy, making the traveling weight closer to 500lbs.
We needed two big pontoons on either side of the rear, primarily to support the riders and the canopy. We also added a large front float that was sized to support the heavier front with enough extra on top to float the entire payload.
These smaller blocks had to be carved from the giant block. We were going to set up a hot wire saw, but I couldn't get that together. Andee tried pulling cold wire through the foam like a lumberjack. It was a lot of work for not a lot of payoff, so she switched to the handsaw. That was also a slog. Then I remembered that we owned an electric chainsaw. Things went more quickly after that.
We mounted the side pontoons on 3/4 inch threaded rods that stuck out from the side.We used ratcheting straps to secure the front float.
I Have a Bad Feeling About This
After finally getting the driver's side pedals connected, we tested the road gear. It worked great on a clean, flat surface. But any obstacle--like a loose bolt on the floor (smh)-- caused the belt to slip! Thinking it was a tension issue, I tightened the belt as far as it would go. This seemed to work, but the belt would still skip in one spot for some reason.
That reason was I had tightened the belt so much that I deformed the steel wire in a section of the belt. I loosened the belt hoping everything would settle back down. The surface returned to its original shape but the steel wire just oozed out of the belt like toothpaste.
The belt was blown, and for some reason I didn't have a spare (yea, I forgot to order spares). Now, we had a big problem. Unless we reconnected the wheels to the driveshaft, we weren't racing anywhere. And we could only do it with the parts we had on hand. It was a very MacGuyver moment.
The front and rear wheels use motorcycle chain to connect to the Hyperdrive, so we had plenty of chain. If we moved the rear-wheel drive sprocket to the main drive shaft, sacrificing our all wheel drive, we could then use the big chain to connect the drive shaft to the front wheels, but we still had to route that chain around the guts of the Hyperdrive. We still had two tensioners/idlers (also intended for the rear) that could be used in the re-route.
At 11pm on race eve, a plan was formed to save the Falcon! I then spent the next 4 hours trying to implement this new plan. It took a while to figure out a chain path that didn't run into something.
I did find a path, but the position of the newly placed rear idler kept slipping under any load. I eventually just put a bolt through it to keep it aligned. Finally, the drive bypass was ready.
Time to go
All these issues ate up what time we had left. After all that effort, Andee's side of the sculpture was still a passenger seat. That last freewheel shaft was too large to sit in its bearings. The universal joints were too small. We tried to put it all together at 9am, but we were already late for race check-in. Regretfully, we stopped work. That was quickly replaced with joy as we loaded out and headed for the start line. We were on our way!
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