Quote:
Originally Posted by Triapod
It was our team's first time working with pneumatics and we reached several issues when getting the intended results. We wired the compressor to two cylinders in parallel, then to the two-action solenoid, and then to the piston.
However, we did not achieve the amount of power we wished for, even with the maximum pressure  . Two cylinders were used, and the piston used was the one close to the size of the cylinders.
The two action cylinder did not give the intended results when it came to kicking and retracting. When wiring the front, and back to the two-action solenoid, the kicking (although weak) occurred at a near-to-expected speed, but the retraction acted as if there was some resistance; retracting slowly. This is a problem, considering the 2 second limit.
A diagram with an explanation would be greatly appreciated.
Thanks you |
Correct me if I'm wrong: Your 2 issues are kicking force and retraction speed. Both are probably because of your tubing (not wiring) setup.
First kicking force: As the cylinders start to fill the pressure begins to build within the cylinder and the rod and seal begins to move (this is while the pressure has only built to under 5 PSI). As more air comes in the rod and seal move faster but the pressure does not build (very much) in the cylinder until the cylinder hits it's stop, this is because the the expanding volume within the cylinder balances with the incoming air. The amount of air allowed into the cylinder is restricted by the valve Cv (flow rate), thus filling 2 cylinders with 1 valve will produce almost no appreciable force gain, and may actually lose force. Locking the cylinders (with a gate latch?) 1/2 way through their stroke and then chargeing the cylinder to 60 PSI will give you far more kicking power (when the gate latch is released) even though your stroke will be 1/2 the distance.
Retraction speed: This is governed by the Cv of the valve as well (as well as any restrictions to atmosphere). Ganging 2 valves may provide better dump flow but you need to take care with any fittings you use so as to not restrict flow with them (stay away from "tees" and use 'Y' connectors, look for press to lock rather than barb fittings, etc).
If you have any other questions, ask away ... thats what we're here for.
