MWF Morphing Handcycle Project Blog

Alan Ball is on the left, with newest team member, John Baron, on the right. They are standing in front of John's brand new barn that holds his machine shop.
 
John is a mechanical engineer, an avid cyclist, former racing cyclist, avid mountain biker, former race car designer and builder, and all around excellent mechanical engineer. Plus, he has a fully equipped shop that can do 3-axis CNC machining, aluminum welding, and just about anything else we might need.
 
Alan Ball is an industrial designer, and he and John work together on projects. Alan recruited John to the project, and today is the first meeting.

Rory introduces John to the Morph (s).

Alan's dog checks out Morph II before its high-tech weigh in. It comes to 58 pounds.

Now John Baron is holding Morph III. Weight came in at 40 pounds. Much of the savings was due to clever work by George Reynolds at Morph III's first home in Derry, NH.

Morph III uses clever locking gas springs that are made in Germany. This lets you control the morphing process, and it lets you stop the bike at any convenient height to get on and off. That is really great, since getting on a low handcycle can be quite a challenge for many riders.

These footrests were designed by Geoge Reynolds. They are extremely light, and have a wide range of adjustability.

The black cords are the centering spring to keep the steering upright, especially for times when you must push the bike using the rear wheels. (Or when you are morphing up or down.)

Front end closeup, low rider mode. If you extend the line of the head tube, you'll see that the bike has negative trail. (The extension of the head tube hits the ground behind, rather than ahead of the contact patch.) This negative trail is a problem, and we'll need ot reconfigure the front end eventually. But it will work for now.

Our first meeting to discuss Move with Freedom. 

John Baron has joined the Move With Freedom team, and the gears in his head are already spinning.

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After six months of winter fabrication and occasional hibernation in George Reynolds wood-stove-heated shop, the new Morph III aluminum prototype is about to emerge.

George Reynolds fixes a few last minute items before the Morph III goes for its first road test.

A very silvery Morph III.

Morph III and George, smile for the camera!

Portrait: Man and Morph.

Portrait: Morph III

A very happy Rory McCarthy rides Morph III for the first time. Two main goals of the new design are achieved. First, the goal was to reduce the weight of the original steel prototype. That goal was achieved handsomely. Morph II weighed in at a stout 58 pounds. Morph III? Just 40 pounds! A full five pounds less than we estimated might be possible. We owe much of this to George's clever work with aluminum bushings.
 
The second goal was to get the low rider seat height down. That too was achieved.

A man and his morph. Rory does look happy. (I wasn't there...George must have taken these photos.)

Side view of George Reynolds on Morph II.

Rory and the emerging fleet of morphing handcycles. Morph II proved the concept, and Morph III proved that we can make a light, low handcycle that morphs. At 40 pounds, the morph is just six (!) pounds heavier than the Bobby Hall handcycle that we use as the "gold standard" comparison.

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Online design session April 10, 2009 with Alan Ball, Rory McCarthy, and Bill Warner.
 
The model shown here is basic geometry from the Morph III design.
 
The goal of the meeting was to see if we can pick a geometry that gives us zero or close to zero trail in the high rider mode, and around 2" trail in the low rider mode

Version 1: .92 negative trail in upper mode. Steep head tube angle (measurement not shown

Version 1a: .Range of head tube angles available in upper mode where trail would be zero.

Version 2: 2" Trail in low rider mode. 10.21 fork length.

Version 2: 1.21" trail in high rider with 10.21 fork. Note that head tube is steep (not measured here)

Version 3: 2.03" trail in low rider. 35 degree head tube angle is still steep.

Version 3 Added pedals to the model, and pedal offset from steering tube angle.

Bobby Hall looks like 27 degrees head tube angle, measuring from this photo by Rory.

Version 4: 1.90 Low rider trail, 11.21 fork, 27 degree head tube angle like the Bobby Hall.

Version 4: High Rider, with 1.34 negative trail (may be too much)
 
Shorten the 11.21 dimension to 10.7 to reduce trail in upper mode:

Version 5: High rider with .95 negative trail

Closeup: We adjusted the fork length as the easiest way to affect trail.

Version 5: Now 2.6" trail in low rider mode. 27 degree head tube angle.

Version 6: Drop trail to almost zero in high rider: trail .18"

Version 6: Low Rider trail becomes 3.96". Too high. Version 5 looks like a good solution.

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Posted below is a GIF animation of a self adjusting seat angle mechanism. This mechanism, or linkage, allows the seat to change angle while the frame is articulated. Right now the seat adjust from 5 degrees tilted back in the low position to 5 degrees forward in the high position.

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Rory and I implemented the "twin flanking members" concept into the Solidworks database and created these animations of the frame morphing.

Here is an animated GIF. Click download to see the morphing action.

The nice thing about this approach is that the twin member design allows the frame to fold onto itself in the two extreme positions, thereby creating additional space for the seat and any seat adjustment mechanism.

Another animated GIF:

I would like to implement the adjustable gas shock into the model, and I will as soon as I can get the dimensional specs of the shock.
 
al

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Well, the best laid plans don't always work out. George sent along these photos of the recent modifications, and its clear that we've gone wrong somewhere. The spirit of this "open source" design process is to show the process, warts and all, so here it is. Somewhere, we made a mistake, because the moving parts don't line up any more. The reasoning was that we'd leave the rear frame geometry alone, and we'd only simplify parts without changing the geometry. Either that idea turned out not to work, or something got changed along the way. Some of the slides from earlier segments are shown here.
 
Part of showing this is to show how hard it is to keep track of the morphing frame without CAD. In fact, though, we did do a little CAD analysis...see Alan's drawings below. But as we all know, Murphy's law is always in force.
 
This first picture shows the ovalized tube in the position we thought it would end up.

   

Click here to download:

The_Dangers_Of_Modifying_Compl.zip (1100 KB)

I think we were going to stay with the curved arm on the bottom as shown in the drawing above.
 
It looks like the new arm below the ovalized tube is now much shorter than it used to be. In the drawings above, I think we were going to wait on straightening the bent tube because it would affect the geometry.

If we're lucky, the whole problem lies in the straight arm being too short. Do we still have the old arm?

Ouch. Morphing wonders turn into morphing mash-ups pretty easily.

Here you can see the new weld that probably took out the bend in the harm, and perhaps made it shorter.
 
George, I promise we will give you clear CAD drawings in the future before your beautiful welds go to waste. Hopefully, this can all be fixed fairly easily.

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The height problem seems to be caused by the stack up of members in the central plane of the cycle. This concept explores creating two flanking members which attach to the ovalized bar. The other mebers can articulate between them, thus saving vertical space. The flanking twin members can be used for the seat mechanism.

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Here is an idea about shaping the "ovalized" bar in such a way to eliminate unwanted vertical space behind the articulation point. Concerned about the strength of this member.

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