My take on the Z-pard

I saw this tech how to in Rockets Magazine and believe Rick V. wrote the article. I really loved the technique and thought that he was on the correct track to make a great deployment system. The only two drawbacks that I saw were that you had to do some welding and you also penetrated the e-bay with the end of the device - giving a slim chance something could fail and the charge fire into the e-bay. Here is my take on it - you still need a lathe to turn an o-ring groove but you don't need to weld anything. Attached is a picture of the layout of the device - in exploded view.

The top aluminum rod with the o-ring is the piston (3/8" OD). The end to the right connects to the nosecone.

Below it is the cylinder that the piston goes into (1/2" OD x 1/16" wall). The left side is internally tapped for 1/8 NPT.

The brass tee is 1/8 NPT and I believe called a branch tee - it has two female ends and the tee part is male.

The bottom part is just a square 1/8 NPT plug.

The top part is a 1/8 NPT to 1/8 tube barb.

The wingnut is on the inside of your e-bay and has a rubber washer on it. The allen head screw goes through the male tee and a small hole is drilled into the bottom of the tee for it to pass through. Another rubber washer seals the device.

An e-match is threaded through the 1/8 NPT to 1/8 hose barb and approximately 1/4 gram 4ffff BP is used.

In all my ground tests it has been very reliable - each time propelling the piston over 20' across the ground.


Edward

View attachment Zpard.JPG

What is it?

It is a way to deploy your chute that is reliable even on higher flights. With this you are only pressurizing a small area and then you have that combined with the positive action of the piston to ensure that the nosecone is pushed off and your parachute extracted.

Edward