Powerpoint and Spreadsheet: Shock location and variable weight riders

[From Graham Butler February 26, 2010]

I think I have a handle on shock position. I have extended the slide show to include most of the process that I went through. There are some things that we can just talk about at 2.

Updated Powerpoint with more information on forces

Spreadsheet showing force calculations for lift system.

More on the Low-Cost Wooden Model That Moves: Designing a Morphing Handcycle By Seeing It In Action

Alan Ball sent along an e-Drawings file of the 3D Solidworks model that he used to cut out the wooden pieces to make the 1/8 scale model of the most recent design of the Morphing Handcycle.  An overview of the project is at www.movewithfreedom.org. This technique of using CNC-routed wood parts is very significant, because it lets us understand a design in "real life" at very low cost.

Note that our next design is going to take some of the concepts in this model, but will go back to a more planar frame, which will have more of a "bike" look. We may use this style of design on a future morphing wheelchair.

Click here: http://www.edrawingsviewer.com/ to download the viewer for Mac or PC. You'll need it to see the files below

Below is another output of the Powerpoint file that shows animations using the wooden model. The previous version used a PDF output, but I worry that the PDF takes a long time to load. Below are JPEGs from that same file. Just click through the images to see the frame animate.

A Wood Model Reveals: How to Understand the Self-Adjusting Seat on the Morphing Handcycle (choose full screen, and set view mode to "slide")

(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)

Just Like Your Teacher Told You, Geometry is Important -- A Detailed Look at the Geometry of the Next Morph

This Powerpoint presentation reviews today's online design session with Alan Ball, Rory McCarthy, and Bill Warner. The goal is to nail down the geometry of the morphing mechanism in stick figure, and then proceed with some basic frame design.
Now that we've got two morphing vehicles on the road, the benefits of the Morph II design are easy to see. It has excellent steering geometry in low rider and high rider modes. Mainly, we need to fix the issue that we can't adjust the seat angle, and the struts provided on Morph II turned out to be an unworkable solution due to the high forces that travel through those struts while you are sitting, and even higher forces while you are riding.
This presentation compares Morph II, the Bobby Hall, and a proposed new design, which essentially keeps the Morph II morphing frame, but allows it to morph through its full travel. Next will the the challenge of designing a seat that allows the proper adjustments.

bobby hall handcycle compared to morph 2 and proposed morph out

I would like to establish the desired dimensions for the next version of the Morph hand-cycle, called "Morph Out". It seems like the dimensions embodied in Morph 2 work better than the dimensions of Morph 3, particularly in regard to ease of turning and "float". Morph 3 is superior in that the low position is lower than m2, and the frame is significantly lighter.
As a goal for Morph Out in the low position, it should match the geometry of the Bobby hall hand-cycle. In the high position it should be as high as Morph 2 high position.
What follows is a pdf comparison of these different layouts, and proposed layouts for Morph Out. Please comment.