I talked with Bimba to see what they thought. A gal in support said that the cylinders should be limited to 20 ips independent of bore size used. She said that the cylinders on the First list had no internal rubber stops to absorb energy. I asked if the load mass mattered… surely a 20lb mass would be more damaging than a 1 lb mass if traveling at 20 ips. This didn’t seem to concern her so long as the 20ips was held.
So I’m thinking most of us are exceeding these limits and therefore should include external stops to preclude piston hammering.
A) 20ips is actually quite fast.
B) Yes, your mechanism should NOT allow the cylinder piston itself to be the stop. That can break the cylinder. Add an external stop, JUST before the stroke causes the piston disc to hit its end plate.
C) IMO, another solution is to just to
use the cylinder to “[MaleChicken] a spring” to a catch (the CDF editor won’t let me use the “Naughty Word” term! <lol>).
disengage / back the cylinder off to its Rest Position.
NOW release the spring with a second tiny cylinder (or other device), by pulling a pin.
A bit more fab and a control ritual, but it saves a LOT of wear and tear on your cylinder because it is not DIRECTLY involved in the firing of the device itself anymore.
