Photos of Test Rig: Morph lift system update

[From Graham Butler April 9, 2010]

I have modified the test fixture and done some initial testing with non-locking gas springs (because that is what we can get quickly)

I have attached a series of pictures showing the current state. With 2 riders.... me at 130lbs and Josey at 245 lbs.   It turns out the the adjustment system works pretty well.  It allows us to adjust the force without changing the shock; but the lift characteristics are not ideal.  There are several reasons for this..... the geometry of the test fixture is slightly different from the CAD model.  What this means is that we are loosing mechanical advantage in low rider mode, so it is hard to morph up.

Josey in low rider mode.
Note that gas shocks meet the upper linkage arm about 2 1/2 inches from the upper rear joint. Notice later that the meeting position is changed for Graham.
The tester uses two separate adjusters, one for each gas shock. On the finished machine, a single adjuster will move both shocks.
Graham in high rider. Notice how much further back the gas shocks hit the upper linkage arm.

PDF: Morph 4 Dimensions Compared to Morph 2

[From Alan Ball: January 12, 2010]

A while ago you requested some orthographic views with key dimensions called out for the M4. Check out the drawing I have attached here. Is this what you had in mind?

For comparison , I have included a drawing of the M2 geometry, which I documented in CAD and was measured and confirmed against M2. As you can see, the basic dimensions are almost the same, with differences occurring due to M4 greater range of morphing motion.

CAD files of M4n - wood model

[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.

Almost Ready to Cut Wood: A Narrow-Frame Design for the Morphing Handcycle: SolidWorks for a Working Scale Model

We are heading towards a "Reference Design" for Morph 4, which we hope will the the configuration that we build six prototypes. This SolidWorks model shows a colored model of a wood model that we will use to finalize the design. The finished bike will not be made of flat sections like this!

This model is deceptive, because it looks so simple. But in fact, it encapsulates almost a year of work to figure out how to get everything we want in the Morph to all be possible in a single design: 

- A good, very low rider height in the Low Rider Position
- A full High Rider position
- Self-adjusting seat bottom so you don't tilt too far forward when you morph up.
- Self-adjusting seat back to you are comfortable in both positions. (looks a little vertical in the high mode here, but its adjustable.
- Narrow, bike-like frame
- Single gas spring (not shown). It will be mounted between the arms. This will be nice and strong.
- Slug seat bottom and seat back. (Not shown, but the room is there to do it.)
- Capability for main tube to have a coupler so you can break the bike apart for travel by car, plane, etc.
- Light weight
- Simplified construction
- Proper steering trail in high and low modes (not easy to get right!)
- Easy to build. (ie simple parts, no fancy construction needed.) (after all, this one will be made out of wood as a scale model)

High mode. Back is a bit vertical, but we can adjust based on length of the green and yellow arms.

Low mode. Note that the dowels are not shown. These will hold the wood model together and let it morph.

High mode.Notice that the seat is tilted more towards the blue tube now. This corrects the tilt that occurs when you morph up.

High Mode Isometric for wood model.

High mode iso. Remember, this is a wood model. Next step is to decide on materials, and on other items, like foot rests, locking mechanisms.

Here is the list of what remains to be figured out after this reference model and wood model:

1. Main tube materials selection - chrome molly steel most likely for main tube. (Coupler not possible in aluminum.)
2. Other members materials - probably many will be aluminum.
3. Design for the morphing joints - how to make it light, strong, reliable, easy to build, easy to repair.
4. Slung seat bottom.
5. Seat bottom adjust mechanism - we show the mechanics, but not the design itself.
6. Slung seat back
7. Seat back adjust mechanism - again, we have the mechanics, not the design.
8. Bike component selections
9. Foot rest design (this always gets too little attention!)
10. How to lock in high and low mode. (and with high reliability! Our current latch design has had its reliability issues.)
11. Desired: a way to lock the bike in intermediate positions and even ride in that mode. (Harder than it sounds!)

And then some things that may seem like minor add-ons, but they matter:

12. How to hold crutches, and make it fast and easy to get them on and off. 
13. Storage space - how do you carry groceries, for example?
14. Water bottles

Additional design issues:

15. How to make it easy to get on and off. This relates to how often people will use it.
16. Design care to be sure the high mode stays short and turning radius is good.
17. Design of pedals so rider can (ideally) turn 90 degrees in high mode)
18. Design of foot rests so rider can turn as sharply as possible in low mode. (ie avoid footrests hitting ground, or maybe they have movement)

Input to Alan for finalizing the wood model:

1. Look at verticality of seat back in high mode. Seems too vertical. Fix before we cut wood!
2. Make the steering work. (Right now its fixed.) Key design issues relate to turning at the steerer tube.

Otherwise, look good to go to wood. The nice thing is that it's very inexpensive to make a wooden model with the technique you've worked out.

Here is the e-Drawings file for the SolidWorks model:  You'll need the free e-Drawings Viewer (for Mac or PC)
(Note: this model is a little tricky because it is set to a small scale. But if you're careful you can get the views that I showed.)