Estes bullpup motor retainer?

[FishnBeer]

Finished my bullpup a few weeks back. Finally got some free time to take the kid out to fire some rockets and everything went pretty well except the bullpup. Bullpup flew straight as a grizzleys wang on a a8-3 but the ejection charge shot the motor out the bottom, so the nose cone barely ejected and the chute barely deployed in time.

I didnt think about it while building but there is no motor hook, was my kit missing the hook? How do you get the motor to stay in?

 

[AfterBurners]

Friction fit the motor with tape

 

[BEC]

Looks like that's what is expected. Instructions show tape wraps around motor but don't make clear why. Odd, that. https://estesrockets.com/wp-content/uploads/Instructions/001972_BULLPUP_12D.pdf

 

[stantonjtroy]

Friction fit w/ tape is as old as Model rocketry itself. The Bullpup (model) has been around a long time, and back in the day there were many other models that used the tape/friction fit by design. I guess there are still a few. I suspect Estes forgot there people building and flying that are newer to the hobby and may not know of this method as a long standing Go-To.

 

[Lugnut56]

When I built my Bullpup, I didn't trust the friction fit method (although I should have as it is proven to work). I used a square jewelers file to cut a clearance notch in the boat tail, and by "tweaking" the engine hook slightly, was able to make it work. Of course, you do still have the hook sticking out the back, but that wasn't a deal killer for me.

 

[Ronz Rocketz]

After my 12D went on an adventure, I built a XL version with a hook.

 

[jrap330]

Finished my bullpup a few weeks back. Finally got some free time to take the kid out to fire some rockets and everything went pretty well except the bullpup. Bullpup flew straight as a grizzleys wang on a a8-3 but the ejection charge shot the motor out the bottom, so the nose cone barely ejected and the chute barely deployed in time.

I didnt think about it while building but there is no motor hook, was my kit missing the hook? How do you get the motor to stay in?

The boat tail is why Estes uses friction fit. It tapers toward the back, making a hook hard but NOT impossible to use/install. Prior to installing motor mount, I cut a notch or cutout in the boat tail and trial and error determine how more toward the rear I needed to glue in the mount. NOW either Estes' design or my mount being slightly more rearward, made the Bull Pup unstable on an Estes C6-3/5 engine. So in your case you need to wrap masking or scotch tape near back of the engine so it is friction fitted in. This is how engines were installed until hooks came out in the early 1970s

 

[crossfire]

Heck M motors have been flown useing friction fit.

 

[jrap330]

WoW....but there is no ejection charge but still, how many wraps of tape doers it take to friction fit a M Motor

 

[Cape Byron]

Dug this out of a box. My Bull Pup built around 2006.



Nicely yellowed paintjob...

I thought I built it stock, but it has a motor hook and a baffle with kevlar shock cord so I'm mistaken.



But I'm pretty sure my Bull Pup came with a hook and instructions on how to cut the boat tail? Maybe my brain is showing its age.