Example of an anti zipper design

[ScrapDaddy]

I know what an antizipper design is as it's self explanigory but can someone show me an example of one?

 

[Der Red Max]

I know what an antizipper design is as it's self explanigory but can someone show me an example of one?

 

[ScrapDaddy]

NOT WHAT I MENT LMAO:roll:

 

[MarkII]

MarkII

 

[ScrapDaddy]

No really can you show me an acctual anti zipper design for a rocket ? Lol

 

[MarkII]

(These are for real.)

https://www.info-central.org/?article=132

https://www.apogeerockets.com/education/downloads/newsletter113.pdf (See illustration in upper right on page 7.)

MarkII

 

[ScrapDaddy]

Thank I was going to have this thread shut down : D

 

[MarkII]

Thank I was going to have this thread shut down : D

After just 2 unserious responses? My, oh my... you really are new to TRF, aren't you?

I gotta admit, though - DRM's post was much better than mine.

MarkII

 

[MarkII]

I really thought that I could find an online resource for zipperless designs, but it was much harder than I had anticipated. That's why it took so long to come up with anything. There was an excellent article about it, with a real good description of the design, its purpose, etc. in the NAR Guidebook. It had great illustrations, too - real clear and easy to understand. That is where I first learned about it. The Guidebook is being revised, I understand (I think that it gets updated with a new edition every couple of years) but I hope that they keep that article in there. I was looking for something on the web that I could show you, but nothing looked quite like that article. The page at Info Central was close, though.

BTW, Info Central is a great resource, S-D, especially for basic MPR and HPR topics. I haven't spent much time at the site since it was revised and updated, but I visited the old site quite often when I was getting back up to speed a few years ago; it helped to answer a lot of questions for me. If anything, the new version should be even better. (Whenever it finally gets finished, that is. )

MarkII

 

[ScrapDaddy]

After just 2 unserious responses? My, oh my... you really are new to TRF, aren't you?

I gotta admit, though - DRM's post was much better than mine.

MarkII

Well.... New being a reletive term.........

 

[Handeman]

I used a zipperless design on my L2 rocket. I now wish I hadn't. I only fly the rocket with electronic deployment which I feel, removes the need for the zipperless design. Of course, I've never had a zipper on any of my rockets, so I probably shouldn't have used that design in the first place. Just my :2:

 

[n5wd]

Here's a vote FOR zipperless designs, and I usually thrown in a baffle so that I CAN use motor ejection if I want, but don't have to.

You can see the thread at:https://www.rocketryforum.com/attachment.php?attachmentid=3947&d=1237995179 and the first post gives you an example of what my zipperless design looks like with the baffle installed instead of a plain bulkhead.

Wayne

 

[ScrapDaddy]

Hey markII go back to the other thread I have another quetion lol :roll:

 

[MarkII]

You can see the thread at:https://www.rocketryforum.com/attachment.php?attachmentid=3947&d=1237995179 and the first post gives you an example of what my zipperless design looks like with the baffle installed instead of a plain bulkhead.

Wayne

Yup, that's it! The rocket separates into two sections right above the motor mount/fin can (usually). A large hollow coupler projecting out of the aft section is what keeps the two sections together. It often contains an ejection baffle and is topped by a sturdy bulkhead which is where one end of the shock cord is attached. The upper section is hollow all the way up to either the base of the nose cone or the base of the payload section. The nose cone or payload section is permanently attached. The other end of the shock cord runs up inside the upper section and is attached to the base of either the nose cone or payload section. The parachute is usually attached to a loop in the shock cord just above or at least not far away from where the cord attaches to the bottom section. The parachute is folded and then wrapped "burrito-style" in a protective heat shield or deployment bag and placed in the upper section with some of the shock cord wrapped around it so that when the two sections separate, the cord promptly pulls the 'chute package out of the upper section. The rest of the cord is coiled up and laid in the upper section alongside the parachute. The long, non-stretching shock cord allows the two sections to separate for quite a distance, which gives them time to slow down as they lose momentum. The shock cord never pulls against the lip of a body tube at any time in the sequence, and so it cannot produce a zipper.

I like the design and I am implementing it for the first time in one of my rockets. I realize, though, that it is not necessarily the best option in every case. It is one option out of many.

MarkII

 

[Pantherjon]

As the saying goes 'a picture is worth a thousand words'..Here is an example of a 'zipperless design'..My 3" Thor..Coupler glued halfway into the booster tube and recovery harness connected to the 'baffle'..