[From Alan Ball - January 12, 2010]
Attached to this email message is a pack 'n go of the solidworks model. Please note that I built this in SW 2009, so you may not be able to open it. With this in Mind I am sending you some edrawings, and also a step file and an IGES file( in the zip file). I hope this is sufficient for you to see what we have been up to.
The Morphing Handcycle has always had a tricky issue: can we stop the morphing part way for getting on and off, or even for riding? So far, we haven't been able to figure out a way that works easily, and that can handle the forces that occur during riding. On Christmas Day, Alan Ball delivered this wooden model with the goal that we could figure out some of the remaining design issues by using the 3D system used by the ancients: Something you can hold in your hand and grunt at.
Here's our advanced polymer, along with a linear fiber-based green material (wood). This unit will stow below the two flanking tubes, leaving room for the red part of the frame to nestle between the two black parts. Then the rider will deploy the lock by rotating what here is a wooden dowel.
Here we see the lock deployed to it's proposed "middle" position.
Here, the lock is rotated further forward, and will lock the bike at a higher position. Note that the lock is mostly in compression, but there will be some of positive lock to handle negative forces (tension)
Now we're in the lowest position that the lock can handle.
A wider view of the lock, now in the lowest intermediate position.
The lock in the "stowed" position. Well, kind of. It will actually have to stow below the flanking members. The hinge that holds the lock will also be a bridge that supports the two parallel frame members.
This is how the lock rotates into position. It will mate with something that that's on the red main tube.
Philip Robson helped design this intermediate lock. Bill and Philip worked out many different positions for the lock, and this one turned out to have the best characteristics. My niece, Molly, gets much credit for bringing Philip to visit Boston from London, where they both live.
On Chrismas Day, Alan Ball brought over a wonderful present - a working, 1/4 scale model of the Morph 4 prototype. Jake, our dog, is check Alan out. The wonder of this design is in how simple it looks, but how much it does. I believe we are now ready to design in metal, and build five or six prototypes so people can really experience what its like to ride a morph. What it's like to "get back the Z", meaning that you can go up and down, and not just ride around at 18-21" off the ground in a wheelchair. The Morph goes from bar-stool height in the high mode to a low and fast 13" off the ground for speed in low rider. Both modes are a thrill, but you just can't explain to people what it's like to be riding at bar stool height. You see everything in a new way compared to a wheelchair. So we need to make some prototypes and let people try it for themselves. More details about Move With Freedom, our non-profit, is at www.movewithfreedom.org.
Our previous iteration of the Morphing Handcycle wood model was much more complex in look and form, although all the joints are actually in the same place. The goal of bringing the Morph back to its "planar" and more "bike like" form has been achieve in the new red and black model. Nicely done, Alan.
Our previous design sought to move the rider load closer to the rear wheels, so the frame members moved to the outside. Nice idea, but the bike ended up with a wheelchair look, and it felt more complex. It also lost that "I've gotta have that" look and feel. So we want back to the drawing boards. (Well, Alan did.)
Ah, what a difference a day makes. Okay, many days. But now we have that beautiful look again, and the Morph has all the features and range that we're seeking.
Cool wheels, huh? That's plexiglass with a notch machined on the outer edge to hold O-rings. Hey, I get credit for that one.
Again, for contrast.
The magic of the blue joints. These are the magic links that make the seat bottom and the seat back adjust their angle as you morph up and down.
Note how far above the red main tube the back of the seat bottom is.
Now look at the red main tube. It rises almost to the bottom of the seat. But it doesn't tilt directly with the red main tube, which is how things used to work.
(Set viewer to "SLIDE" mode shown on lower left so animations will work)
This Powerpoint presentation and animation uses Alan Ball's clever and low-cost 1/8 scale wooden model to let us see how the seat bottom and seat back magically change angles to correct for tilt when the bike morphs up and down. Very cool, and it really works! (Note: this is a re-post using a PDF format from the the original Powerpoint)