Piston System Kit
PS-2.1
Regular price Sale price $12.31The operation of the piston system is quite simple. The piston sits in the airframe "over" the motor and "under" the parachute. It is attached to the motor mount via the nylon strap which is epoxied to both the motor mount and the piston itself. When the ejection charge goes off, the pressurization between the motor and the piston bottom pushes the piston upward, which separates the rocket and pushes the chute out. That`s all there is to it. No special prep needed, nothing to do...just push in the piston, load the chute, and you`re done.
Have used PML pistons on many rockets, even scratch built designs. Enjoy the ease of loading and the positive chute protection provided by the Pistons. Never had any issues with blow by scorching a chute as I have had from time to time with Kevlar/Nomex chute protectors. The one down side is that in order for the piston to slide easily in the airframe you need to clean off BP residue from the previous flight (which can easily be done with a simple brushing) - and this works best with Fiberglass, Quantum Tube, and phenolic airframes (cardboard airframes in general are more difficult to clean and, never having used Blue Tube can't speak to that at all). You also have to consider how atmospheric conditions affect the components (swelling/shrinking of tube and piston from temperature and/or humidity changes - what worked great in the dry California environment gave me fits until the interference was readjusted in the humid Texas climes). But properly adjusted a piston ejection system is fantastic. And great for dual deployment systems where the pistons are located on each side of the AV bay and body breaks for chute deployment are located at the nosecone and just ahead of the aft end motor mount.
I absolutely love the piston system. I do use the for Dual Deploy on the PML Kits with Quantum Tubing using a LOC Phenolic Altimeter bay. They work fantastic. Main thing to remember is to follow PML's Guidelines on Black Powder Charges. It doesn't take very much. I see folks using way too much black powder for the ejection charges. The Quantum tubing is a breeze to clean and makes the piston ejection work like a charm. No chute protector is needed and i even run a Jolly Logic chute release on some of them as well.
First, I want to say that the piston system isn’t for all rockets. Cardboard rockets and dual deploy rockets I would rather not use the piston system. Cardboard doesn’t clean up well, alcohol soaks right into it. However, quantum tube and fiberglass are a breeze to clean BP residue after a deployment. I reiterate, the piston system doesn’t lend itself to dual deploy rockets where the electronics are placed in the coupler; you can’t run your ejection charge past the piston, though, you can easily use the piston system in the payload section to deploy the main chute.
