| 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 |