Rory, Graham, Alan and Bill met on Tueday, Feb 2 by screen share. This post will review the decisions made.
Decision 1: Pursue dual gas springs, mounted inside of the two upper morphing arms
There were three choices for the gas shock (we also call it a gas spring.) Choice 1 was a single shock that didn't protrude, but that requires a custom shock. Choice 2 is dual shocks (the choice we picked) and choice 3 was a single off-the shelf shock that would be longer and would have an extension that would hold it down
This sequence will let you create your own animation of the morph up/down sequence showing the action of the gas shock.
This animation shows Choice 3 - a single, longer shock, mounted further along the morphing arm. The good news here is that the total force from the shock can be lower, because the mechanical advantage for lifting is higher. But we didn't like the look of the shock protruding out of the mechanism. Also, Morph 2 uses two shocks, and it has that "magic." We don't know what a single shock would be like.
Custom Shock Side View.
Custom shock top view.
Here we have the custom shock solution. One big, powerful shock mounted at a partial distance along the morphing link arm. But here's the shocker: due to the longer range of Morph 4 compared to Morph 2, this shock needs about 1000 lbs of force for a 250 lb rider. Wow! We don't want a single shock with this much force, and we don't want a custom solution.
Rear view of the dual shock approach. We're going to see if the two shocks can be mounted inboard of the struts, rather than with the small extension. With 500 lbs on each shock, that' creates a lot of moment a the mounting points.
Side 3D view of the dual shocks.
Adjustable Lift System
Adjustable Lift System - This side view shows the idea of some of the lifting force being supplied by an elastomer (shock cord). The cord is shown in red. In the low mode, the cord is stretched, and it is providing significant lifting force. By changing the where the cord is attached to the forward frame, we can instantly adjust the up force. This adjustment will be done when in high mode, where the cord is slack.
An idea for the upper morphing arm. Teardrop shaped tubing with a machined end that is welded on. Not sure this is an ideal design.
Bearings are captured in the clamp?