Quote:
Originally Posted by Matt H.
Preloading the cylinder increases the system's energy output by maintaining that force over a longer distance.
|
For a
given kicker design, preloading gives a higher force over the same distance, yielding more energy.
Consider two
identical robots which both have mechanical latches to hold the kicker in the "armed" position, and which both have the piston in the 35% extended position when in the armed position.
The only difference between the two robots is that Robot A pre-charges the cylinder with 60psi, whereas Robot B does not.
The piston in Robot A and the piston in Robot B both travel through the same stroke when kicking.
Because of the pre-charge, the pressure in Robot A's cylinder will be greater than the pressure in Robot B's cylinder at the start of the kick (and perhaps even throughout the entire kick).
The greater pressure results in greater force, and the greater force acting over the same distance results in more energy in Robot A's kick.
Now remove the constraint that the two Robots are identical. Instead, Robot B's kicker design is modified to provide a longer stroke, by retracting the piston further.
Now it isn't so obvious any more which system will delivery more kicking energy. For a very interesting discussion of this situation, see vamfun's post#12 in the following thread:
http://www.chiefdelphi.com/forums/sh...ad.php?t=81145
His conclusion, in a nutshell, is that it is better to use the full stroke (and not pre-charge) the small-bore cylinders, whereas it is better to pre-charge (and not use the full stroke) for large-bore cylinders. The reason for this ultimately traces back to the 1/8" .32 valve restriction. Note that the conclusions in that post are based on using greater stroke for the non-charged scenarios (as in the "non-identical" kicker design scenario above). Note also that the conclusions in vamfun's post are based on a set of operating assumptions (especially load) that may be different in your kicker design.
~