On Wednesday, May 20, 2020 at 11:09:55 PM UTC-4, 2G wrote:
On Wednesday, May 20, 2020 at 5:42:13 PM UTC-7, wrote:
On Wednesday, May 20, 2020 at 5:57:36 PM UTC-4, wrote:
I'm neither a software nor mechanical engineer, but I think the relationship between force and deflection might be linear, not exponential

Yeah, was thinking energy, ie. stored energy that's going to come back also.
With a linear-ish shock absorber, the energy dissipated is linear.

With a bungee/spring alone relying on a weak(er) link, not much happens until you get very close to the breaking condition. With linear energy dissipation you can tune the release condition much better, and you won't have the springback effect.

Show me the data that any such tuning is even possible. I have just described how it isn't.

Tom

The only comment I've seen from you wrt shock absorbing was about bungees. I should make it clear that that's not what I'm talking about when referring to shock absorbers. I'm talking about the shock absorbers you use in car/motorcycle suspensions. The racing stuff is fully tunable via preload setting, compression resistance and rebound.

For towing gliders, the preload should be set to somewhere near expected 'normal' tow load on the rope. Compression set so that by the time the absorber has travelled the full length (and releasing) the energy dissipated is less than would cause the tow-plan to stall. Rebound setting should be relative to the energy gain for the ow-plane in 'normal' tow. With such settings, it should be impossible to pull on the rope enough to cause the tow-plane to stall.

This doesn't solve the pitch issue, but I'd rather be nose down not stalled than stalled.