Comparing the Morph and the Travel Bike - Side View Photos/CAD

The previous posts review the Travel Bike, because it shares many design elements with the Morph. Having just spent the weekend in Newport on the Travel Bike (as I wait for the Morph 4 to be completed!), I wondered if we could use the very cool hinged footrests from the Travel Bike. The short answer: No. The Travel Bike, as compact as it is, is way longer than the Morph in high rider mode. And your legs sit well ahead of the steerer tube, as opposed to behind the steerer tube in the Travel Bike. Too bad. The Travel Bike's footrests are light and functional. Here's some more details.

Side view of the Travel Bike.

I used Keynote's instant alpha feature to grab the CAD Man from the Morph pictures. I scaled both drawing so the front wheel was the same size.

Using the same scaling techniques to see the Morph in Low Rider next to the travel bike. Note that you sit about one full head height lower. The overall length is about the same.

Adding the Morph in high rider, we see how much shorter and higher the bike is, even compared with the (mostly grayed out) Travel bike.

It's interesting to note how much more your leg bends from low rider to high rider. This is because the seat moves up and forward, but the footrest stays in a similar place (it does rotate about the front contact point, I think.)

Like I said, no but you'll see.

The instant alpha took away some of the foot of our CAD Man.

These footrests are hinged at the top of the vertical orange line, and also where the two lines meet. Go off a big curb? The footrest just bends forward, no problem.

Red lines show center line of your shin in both bikes.

I hadn't realized that the seating position relative to the steering axis was that much different. It's a good 16" (size of the front wheel). This keeps the Morph short, which is really crucial for indoor maneuverability.

And there you have it.

Morph 4 Design Review - Screen Images

Bill, Seth and Graham had an extensive design review online today. The screen images are presented here. Later I will make posts that provide annotation. But for now, here's how things look. There are some little elements on the main tube that are not supposed to be there. (they were for an elastomer-based adjustable lift system that we didn't end up using.) Otherwise, things are getting very close. More later.

Some of the images show a yellow triangular upper morph arm. We decided not to use this. It creates a confusing look. Later images go back to the original design.

Backpedal Brake: Post 3: "Deadman Release" and Bumper

[From Graham Butler March 15, 2011 Input from Bill Warner and a mechanical engineer in at a Cambridge rotary compressor company who suggested the "deadman switch" idea like on a chain saw.]

I just got back from Brazil at the end of last week, things got hectic the last couple of weeks before leaving.

I think that the last we left the design, we had talked about a 'deadman's switch' for the brake release.  It makes sense.  Check out the attached screen shots of my first hash.  It is very simple.

Talked to Seth today.  We are getting material ordered so that he can build front forks.  I figured that while some aspects of seating might change, it is very unlikely that the front fork geometry would change substantially.

Morphing Handcycle Reference Design V1 Released


Morphing Handcycle Reference Design - Low Rider, Side View


Morphing Handcycle Reference Design - High Rider, Side View

Move With Freedom has been working on the design of a practical Morphing Handcycle for a few years. We are now at an important juncture where we switch from the design process to that of helping the product get into production.
Move With Freedom makes open source designs. The design process can be traced right to its beginnings by looking at the posts in this blog:  You can see a movie of the Morph in action here.
Our designs are free and open to anyone who wants to use them. At the same time, we want to encourage manufacturers to add value to our designs and put them into production.
So, today we are announcing two important developments:
1. Availability of the Morphing Handcycle Reference Design V1 (PDF)
2. Move With Freedom, Inc. has placed an order with Intrepid Cycles for four production Morphing Handcycles, 
If you would like to design your own production versions of the Morph, we are ready to help. Just ask for what you need.
What follows are some illustrations from the document:


Morphing Handcycle Reference Design - Schematic of Key Components


Key dimensions are provided for all schematic parts.


Automatic Seat Tilt Linkage is explained.


Calculations for the Adjustable Lift System are provided.


A detailed design for the morphing pivots is proposed.


Dimensioned drawings are provided for all key parts. (This is a partial view)

Here is the Morphing Handcycle Reference Design V1 (PDF)
Note that you can download this document by clicking the link at the end of the post.


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.

What Makes a Morph Go Up and Down Like Magic? Animations and Lots of Details Here

This is a big post that will review a wide range of design choices on Morph 4.

First up is the design for the "lift system" - the gas spring and any other elements that make the Morph...well... morph. Here we see a design that uses a single long-stroke gas spring that fits in between the dual arms of the upper and lower link arms. This spring would be rated at about 500 lbs of force. It is an off-the shelf shock from McMaster Carr:

Details on the single shock. Click here to see the gas spring online.

Morph 2 (and its modified version, Morph 2.5) uses two gas springs. We're debating right now which is better. With two gas springs, we can have more force, and the place the springs closer to the hinge point. This means a smaller shock, and maybe a neater look.

Side view animation. Gee, the single gas spring seems like it's hanging out in low rider mode. Is that cool? Or wrong? Note the "extension" that holds it to the upper morphing arm. This member is only in tension. It is like the vertical cables on a suspension bridge.

Rear view animation. Note that the big shock "pokes up" in Morph 4, but in Morph 2/2.5, the gas springs protrude downward and are handled by an extension from the axle tube.

Note the two thin extensions welded to the axle tube. These welds actually failed on Morph 2 because there is about 250 lbs of force acting at a distance on these extensions. But they do serve to allow a longer gas spring to fit into the system. I believe  we could use a similar approach on Morph 4.

We decided to look into this some more, and scheduled another online meeting for Tuesday, Feb 2, 2010. Or calls uses for screen visuals, and we are in Bath, Maine, Cambridge, MA, Somerville, MA, and Santee, CA.

Adjustable Lift System

Let's say you weigh 170 lbs, and the gas shock is sized just for you. You want to show a guy who's 200 lbs exactly how cool the Morph is. Well, it won't work that well, because the 200 lb person is 30 pounds over the design weight. This means that he will sink down fast to low rider mode, and will need to work a bit to get up. He won't have that wonderful "float" that makes the Morph so amazing.

We would like to have a fast, easy way to adjust the lift system. One idea is to have the gas spring handle part of the weight, and have an adjustable elastomer system handle the rest. Those are the red cords in the picture above.

X-ray view.

You can see the elastomer cord bisecting the "diamond" of the frame, and then going inside the main tube, then emerging to a hook. What hook you set it on determines how much supplemental force you get for the lift system. Want to change it? just move the hook when you are in high rider mode and the cord is slack.

This is one proposed supplemental lift system. Just hook it to get the lift you want. We're still working on other ideas. The silver item below the cord is the coupler that lets the front and back of the bike come apart for getting the Morph in a car.

We're debating aesthetics vs ease of construction. Here is an upper link arm with straight tubes. Much easier to make, but will it have that "cool" look that gets people excited? Other arm has the cuts/and welds shown.

Aye, she's a beauty, but oh, the work to make this part. Cuts, welds, and precision machining for the bearing races that mate at either end.

This design avoids having to seat bearings at each end. Uses ball joints. Hmmm.

Here's another way to complete the tube. A machine insert that is welded on. We're also thinking about teardrop tubes which would look much better than rectangular.

In the previous post, we had an issue with seat clearance to the main tube. The new design moves the cross-member further forward, so the horizontal supports can straddle the main tube.

A look at an assembled version using ball joints. I like the ball joints for the little seat adjusters. Not sure they're great for the main morphing joints.

Here is the e-Drawings file for the SolidWorks model:  You'll need the free e-Drawings Viewer (for Mac or PC)