inertia arrow rest

Originally Posted by geoffretired

I've made the equivalent of a mini sized shock absorber. I'll fill it up and see what happens.
Thanks

Success may depend on the viscosity of the cornflower mix, you will need to play with the proportion of cornflower/water mix for optimum results.

There is a synthetic version of cornflower Geoff...watch this space

[simon m]

Have a look at motorcycle steering dampers.....used to stop "head shake" under large throttle opening......they prevent fast movement but turning the steering at normal speeds is possible.

Also some of the newer armour(in leathers) has a silicone layer in it that hardens when hit fast but is pliable when deformed slowly.

Just some thoughts.

Originally Posted by simon m

Have a look at motorcycle steering dampers.....used to stop "head shake" under large throttle opening......they prevent fast movement but turning the steering at normal speeds is possible.

Also some of the newer armour(in leathers) has a silicone layer in it that hardens when hit fast but is pliable when deformed slowly.

Just some thoughts.

Hmm bikes, what road bike do you ride Simon?

[Max]

Geoff - cornstarch is the stuff you are thinking of - a non-Newtonian Fluid (not liquid). Actually a colloidal suspension - the individual particles in the suspension will slide slowly past each other but resist rapid displacement. This only happens when the fluid has a certain concentration of starch to water. It is great to demonstrate the principles of non-Newtonian fluids but not very stable. I would stick to basic fluidics or hydraulics, using variable restrictions. The SCAT release uses a similar principle, but backwards, so a timed release happens after the trigger is released as opposed to applying pressure to the release and waiting. Good luck!

[simon m]

History or currentely?.

VFR400
zx6r J1
zx6r A1p (trackbike)
Currentely
Fazer '05



Me and the fiance ride that(she got a license a year after I did)

Originally Posted by simon m

History or currentely?.

VFR400
zx6r J1
zx6r A1p (trackbike)
Currentely
Fazer '05



Me and the fiance ride that(she got a license a year after I did)

I miss my bike ....sob

[simon m]

Sorry for the thread hijack geoff!

[Adam]

Originally Posted by rgsphoto

I have no idea? Your the inventor Geoff, get experimenting. Honestly try it, it's really odd the way it stiffens up with agitation/violence. It is worth looking into.

Same as custard powder, and it's called a thixotropic substance if my memory of school science is correct.

Geoff, I presume your "inertia" rest will be similar in priciple (if not in practise) to the old Barner rest?

Adam

[Rik]

And of course there was a practical demonstration of the effect, on Braniac - Jon Tickle walking across a swimming pool full of custard.

It was fine until they got him to stand stil and demonstrate how he would sink slowly, with no vigorous movement. The problem was lifting him out again...

[geoffretired]

Thanks for all the helpful info. i am curious about cornstarch but water and aluminium together worries me. The restrictors are the bits I'm on at present. Not much room for error in the sizes so I will be some time getting it right.
Adam remembers the Barner rest??!! I made one like it but it was too bulky. I then replaced the piston movement with a pendulum. The weight on the end gave the inertia. However I could not get rid of variables as the machining was needing to be accurate beyond my means. So now, the cam is held in its cocked position by a post that can be pulled away by a system of levers and cams that are operated by the movement of the cable slider. I can e-mail pics but not sure I can post them here. It is very simple and works consistently. Thanks again for all the advice
Geoff