BT-80 Build Question

[Globulus]

Hello fellow rocketeers! I'm a newbie to the art of scratch building. Recently got back into rocketry after years of inactivity due to the interest of my nephews.

Was never good at building rockets, but recently got real into it and have been addicted to building from scratch. I've made a few BT-60 sized rockets and wanted to move into something bigger. Because bigger is better, right?

My question is, if I have two 10in BT-80 tubes connected by an ejection baffle, will a normal sized 24mm motor and motor tube be big/long enough to blow the nose cone off given the size of the larger tubes? I'm not sure if I need a longer motor tube like the big daddy (stuffer tube?)

I just wasn't sure if having the bigger body tubes will diminish the force from the ejection charge from a normal sized 24mm motor and motor tube.

Thanks!

 

[bad_idea]

Welcome to the forum, and congratulations on going the scratchbuilt route. It's very rewarding and a great way to learn.

Without the baffle, I wouldn't worry about it too much, but a stuffer tube rarely hurts so long as it doesn't impinge on space for recovery device. With a baffle, I'd take a little more care. Since your laundry is necessarily going to be forward of the baffle, I'd probably go ahead and and run a stuffer up that far.

With BT80, I'd seriously consider going with 29mm or 38mm mount and adapting down. As I've acquired more cases, I come to regret having built several rockets with mounts a lot smaller than they could have had. Not everything needs to be minimum diameter of course, but it's nice to be able to put bigger rockets up higher as the field and flying conditions allow.

 

[BABAR]

Welcome to TRF.

I am a fan of stuffer tubes for wider rockets. Since you are going to use a coupler anyway, you can build your baffle into the coupler. Sounds like that is already your plan.

Concur with @bad_idea , if there is any chance you are going to go up a motor size, use a larger mount tube from the tail to the coupler/baffle.

Don’t forget to add some sort of anti-zipper modification for your shock cord. The good thing about stuffer tubes is the effective ejection force is higher. The bad thing about stuffer tubes is the ejection force is higher

 

[Globulus]

Thanks for the replies! I think I'll go with the longer motor tube, almost up against the baffle. Definitely going 29mm and will adapter down if need be. Looking forward to building my rocket. Thanks again!

 

[Hobie1dog]

to the forum

 

[PDawg]

Welcome back! Just make sure your nosecone slides out very easily, there's several ways to do this and sometimes as a rocket gets old you have to sand things down.