What Is Arcturus?

Since the day I began dreaming up bicycle creations, I have always wanted to create a large human powered camper with an electric assist running on batteries that are self charged using solar power. This vehicle would have to be large enough to sleep at least two people and have enough room inside to stand up and move around. Of course, the entire unit would have to be made extremely light for its size and incorporate space age design and materials in order to remain partly human powered.

With the new power assisted bicycle law introduced several years ago in Ontario, Canada, I could now add a 500 watt motor to the camper as well, so this would make hill climbing a lot easier, and allow for a larger battery bank that would run the motor for at least 50 kilometers, and then power all of the onboard electronics and appliances when parked. The vehicle also had to have no more than three wheels, or it would not legally be classified as a bicycle in my province, so the trike design was the only option and would allow for a more streamlined body.

The inside of the camper area will be 4 feet wide, 10 feet long, and 6 feet tall. The cockpit area of the camper will have about the same size as the Kyoto Cruiser, with plenty of room for two riders to sit comfortably without rubbing arms or shoulders. Of course, there will be a main seating area that also pulls out for an additional two-person bed, a large table, storage area, small sink, stove, heater, and built-in LCD screen, all running off of the battery bank. The battery will self-charge using a large solar array mounted on the roof of the camper and via plug-in during cloudy days or between long hilly journeys.

This may sound like a lot of equipment, but I plan on a total weight of no more than 400 pounds. Four hundred pounds is 200 pounds of cycle per person, and if you include the power of the electric assist motor, pedaling the vehicle will be as easy as riding any bicycle. Regenerative braking will also be incorporated into the custom computer controlled charging system, motor controller and "smart" assist system, which will instinctively know how much power to split between human and motor for seamless hill climbing and acceleration.

 

Getting and Cleaning the Differential

After much hunting, I have finally scrounged up an older front Jeep differential to be used as the "foundation" for the drive, steering, and braking systems on Arcturus. Initially, I thought a Jeep differential might be too heavy for this project, but after adding up the weight of a home built front wheel drive steering and suspension system, I realized that this was definitely the way to go.

By using this 150 pound Jeep differential to contain most of the complex mechanical systems, I actually save weight and end up with an extremely robust and easy to repair design that will last a lifetime. The plan is to adapt a belt drive to the differential so that a very powerful and efficient DC motor can drive the two front wheels. The steering, suspension, and braking system is also included in the front differential, so all of the complex and mission critical mechanics are contained in one area, allowing the rest of the frame and cabin to be made as light as possible. We will be sitting directly over the front wheels in the final design, so it will be easy to connect another control rod to the right control arm in order to create the under seat steering system for the pilot.

The first part will be a 150-lb 1978 Jeep front differential, the foundation of Arcturus's drive system.

When steel sits outdoors exposed to the northern elements for more than 30 years, one can expect that there will be a fair amount of rust. Although it looks pretty bad in this photo, both flanges spin freely and there is almost no resistance when turning the drive pinion. The brake rotors look pretty bad, but the plan is to machine them down way below specification to make them lighter since they will not see anywhere near the force in this vehicle.

Once the entire differential is stripped bare, sandblasted, and re-greased, I think it will look and function as good as the day it rolled off the assembly line in 1978. Another nice thing about this differential is that the drive line can be turned off by simply cranking the 4x4 dial around. Having the ability to make the drive wheels "freewheel" could really come in handy if an electrical malfunction was to occur. Being able to disconnect the drive system in order to push the vehicle out of harms way will be a nice feature just in case.

There is definitely 30 years of rust here! The differential was hidden at the very back of an auto parts dealer warehouse.

After spending a few hours with the wire brush, bolt lube, and a set of wrenches, I managed to completely disassemble the two ends of the differential in order to access the state of the transmission parts. Even after 30 years, the factory grease was keeping all of the bearings and moving parts in perfect order, so that was great news. My goal at this time is to just remove the brake rotors, clean the bearings and then put the differential back together so I can build the frame around it.

After the frame and suspension parts are completed, I will take the differential entirely apart, have the shell sandblasted and the grease all of the moving parts. If the brake rotors are too rusty to be machined, they will be replaced with new units. shown in the photo came from the brake rotor after banging it with a hammer for a while. the rest of the bolts came out surprisingly easy considering the amount of decay around their heads. All bolts and nuts will also be replaced with new ones when the differential gets its final overhaul.

The moving parts are in great shape, despite the rust due to sitting outside in the elements for many years.

It took the help of a diagram to pull this differential apart properly, an although following instructions is normally against my religion, I decided to take the easy way out this once. All of the bearings and shafts were completely cleaned, revealing that all of the important bits were in perfect order with minimal wear and tear. Maybe I got lucky here and this differential came out of a young Jeep with a blown motor? When you scrounge up your parts from a scrap yard, you never know what you are going to get, so luck was on my side so far.

There are many parts to this differential, requring the need for a detailed diagram found on the Internet.

I also found a pair of aluminum wheels from another vehicle that fit perfectly on the Jeep differential, so now I have a perfect foundation to use as a base for everything else. The main frame will be built to carry the 4 foot long cockpit area, 8 foot long cabin area, and the rear wheel swingarm. The frame must also connect the differential to the front suspension and steering system, so some planning will be needed in order to ensure that all of the mechanical systems work together properly.

Everything else will be built around this. A visit to our neighborhood mechanic shop resulted in a pair of wheels.

I am planning to use a non-standard front suspension system that will give the vehicle a very smooth ride, and want the entire weight of the battery bank to be taken up by the differential, so that the frame does not have to take any extra loading. By integrating all of the heavy mechanics into the differential, I am basically building a two wheeled electric car that will just happen to have a lightweight, 16 foot long motorhome sitting in top of it.

The only mechanical part at the rear of Arcturus will be a motorcycle wheel on a simple swingarm suspension system, allowing the body to take on a very efficient aerodynamic "fish" shape in order to keep wind resistance to a minimum.

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