3" Semi-Scale Bullpup Build

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Yes, it's not glued in. It's held in by the aft rail button screw and the two brass flathead screws.
 
I'm cautiously optimistic that the rain will stay away, and we'll have a launch Saturday. So I got the Bullpup XL ready to fly. I'm a little concerned that I may have made the cable too long, and it might cause a zipper. But there's nothing I can do about it now, and I've had and repaired zippers before. I used a 12x12 blanket that I had to protect the laundry. That's a 36" nylon chute, and 15ft of nylon webbing. For a little extra insurance, and just for fun, I put an 18" chute on the nose cone.

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I didn't like the rail buttons with zinc round head screws, so I replaced them with chamfered buttons and brass flathead screws. Yes, I'm that anal.

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Have you had a zipper in a fiberglass body tube? I didn't think that was a problem.
 
What a wonderful, classic, entertaining, and informative build thread!
My launch this weekend got canceled. But I have had a good run so far this year..

Reminds me of my late lamented PML Bullpuppy
https://www.rocketreviews.com/2011-04-09-roc-bullpuppy-110g250-9jpg.html

So what is the motor of choice?

Great thread Captain. Keep em coming!

Very best of wishes. Stay dry! (Goodness, for how many years have we wished for wet?)

 
That's a good looking Pup, Jeff! I have a G75 SU Metalstorm for its first flight. It sims to about 900ft on it, which is perfect for the smaller SARG field. My only concern is the delay. It's non-adjustable, and Open Rocket says that at 7 seconds it'll be travelling at 27fps at deployment. I like to keep them under 10fps, but that's not possible with the SU motor. So I'll say a little prayer to the rocket gods, and hope for the best. I have been accused in the past of building rockets like tanks, so hopefully that will see the Pup through. If not, well, the up part will look good! When I launch it at Snow Ranch, I'll use an H128W or H165R.

I'm actually back in the swing of things, and have three more builds in the works. 5 Times A Fool, Pink Hornet, and Meaner Machine (a 9ft tall 2.6" Mean Machine upscale).
 
I took Dan's advice and wrapped the quick link in some closed cell foam. It's not pretty, but it should help prevent a zipper.

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As you know, like you, after my heart valve replace 3 years ago, AND a new job almost at the same time, I was away for 3 years... so I can be excused if 'life got in the way and I forgot a thing or two'! :lol:

I wish I could depend on simulations to be that specific. :) I too try to accept their advice. Goodness I am sure MANY of my rockets have taken a bigger FPS beating! :)
Were you not an advocate of zipperless designs back in the day? Those take high FPS deployments with a bit more grace. :)

But like you... sometimes I just use the 'thats too short... thats too long... I will try the long rather than rip it apart just after burnout!'

I'll be fine. Especially with the foam.
 
Yes, I used to be quite enamored of the zipperless design. Most of my HPR scratchers are zipperless. But of the four current builds in the pipeline, only one will be zipperless (Meaner Machine). The reason? Most of it has to do with paint schemes, believe it or not. That and laziness. Hey, at least I'm honest!

And I wasn't aware of your heart valve replacement, or I don't remember it. Either way, I'm very happy you're still alive and kicking!
 
I took Dan's advice and wrapped the quick link in some closed cell foam. It's not pretty, but it should help prevent a zipper.
Do you think the padding around the quick link prevented the chute bundle from being pulled/blown out of the body tube this past Saturday?

Given the relatively small diameter of the 3" tube, I'd be inclined to just wrap a bit of masking tape around the quick link and/or shock cord.

I've been using flat kevlar tubing for the fin can cord at a length that reaches a few inches past the end of the fin can body. Attach a quick link or heavy duty swivel to it and you're good to go.
 
Do you think the padding around the quick link prevented the chute bundle from being pulled/blown out of the body tube this past Saturday?

Given the relatively small diameter of the 3" tube, I'd be inclined to just wrap a bit of masking tape around the quick link and/or shock cord.

I've been using flat kevlar tubing for the fin can cord at a length that reaches a few inches past the end of the fin can body. Attach a quick link or heavy duty swivel to it and you're good to go.

That's the way I've done it in the past. With this one, I used a short steel cable. I'm not sure what tangled the big chute, but I have a feeling it had something to do with how I wrapped the blanket.

And where were you Saturday? We had a great launch! David R. was hitting the Dark Matters hard!
 
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