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Unread 22-03-2014, 03:58
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Re: Pistons not extending fast enough?

Quote:
Originally Posted by hrench View Post
Geometry is right, but there is also another trick you can use. If you use a longer-stroke cylinder (we use 11") and don't retract it all of the way, you'll have a volume chamber right in the cylinder you can fill to 60 psi before you release. Also, yes, the other side of the cylinder should be open to atm.


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This will require a latch and releasing mechanism to keep the slightly extended cylinder in place as it becomes pressurized.

As well you should install a safety mechanism.
You will most likely be pressuring your system in queue and swapping batteries prior to taking the field.
We are planning on charging our system in queue. Our system has four 120psi and two 60psi tanks. Since we are not putting our cylinders in a pre charged state we simply extend the catapult and put a channeled PVC pipe on the extended rod keeping it at maximum throw. If our system accidently fires the catapult is already on its stop point and will not put strain on the safety system.
I am a little concerned for some of the straps over the tensioned and charged catapults. Unless the straps a sufficiently strong and TIGHT there could be trouble

Aloha!
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