Discussion of Locking Mechanism and Rear Linkage Arms

[From Graham Butler May 14, 2010]

I just wanted to give you an update....


I have gone through the CAD and started sourcing most of the tubing for the prototype.  Some material has already arrived, some is on order but hasn't arrived yet, and there are still some parts that I am figuring out.

In terms of materials selection I think that the linkage arms (upper and lower) can be made out of aluminum.  The mechanism for adjusting the gas shock on the upper linkage, needs to be made of steel for strength, but I think that there is a way to mount it to the an aluminum linkage arm.  The rear frame and lower fork should be made from cromoly for strength.  The upper fork, crank piece, seat sub frame, and main frame can all be aluminum to save weight.

Fairing has some good double butted teardrop sections that should work well for the linkage arms.

The locking gas shocks are on order from Germany, but it will probably be a month before we hear anything from them.  I still haven't received the shocks from George.

Locking Mechanism:

I have been thinking a little about designs for a safety locking mechanism, to secure the handcycle in low rider mode for longer rides and for safety.  For the lock to be fail safe, it needs to be extremely simple  The simplest solutions are either a simple pin through the frame, or a strong hook around a frame member.

There are also other possibilities, including spring loaded pins, over center latches (similar to the one on morph 2) etc, but the issue I see with a more sophisticated latch is the it has a greater potential to come unlatched and to wear out.

What do you guys think about this.

Next steps:

Once we nail down our prefered locking mechanism and get the rest of the materials in, I should be able to start making parts.  This should happen early next week.