Bullet Bill (Bobby)

[Swifted]

I saw the Launch Lab Rocketry Bullet Bobby on here the other day and I will definitely be ordering one as soon as the wife stops paying attention to the rocket budget.

In the meantime I decided to 3d print a bit of an homage, but to the exact dimensions of a screen capture from one of the Mario games. I don’t love the fins, and if I do it over I may try lexan, even though I don’t like the way it looks either.

There’s a super short section of 3 inch tubing glued directly to the nose cone and the lower section is ejected at the band to the rear, the motor is installed and retained with a 3d printed bulkhead all on the inside of the body tube. Comes down on a 6 inch plastic chute. I got my tolerances a tad tight on the printed launch lug so the first test flight arced over pretty badly, but seemed stable. I have since fixed the launch lug and am waiting for a less windy day to test again.

 

[lakeroadster]

I saw the Launch Lab Rocketry Bullet Bobby on here the other day and I will definitely be ordering one as soon as the wife stops paying attention to the rocket budget.

In the meantime I decided to 3d print a bit of an homage, but to the exact dimensions of a screen capture from one of the Mario games. I don’t love the fins, and if I do it over I may try lexan, even though I don’t like the way it looks either.

There’s a super short section of 3 inch tubing glued directly to the nose cone and the lower section is ejected at the band to the rear, the motor is installed and retained with a 3d printed bulkhead all on the inside of the body tube. Comes down on a 6 inch plastic chute. I got my tolerances a tad tight on the printed launch lug so the first test flight arced over pretty badly, but seemed stable. I have since fixed the launch lug and am waiting for a less windy day to test again.

I'd be worried about the fins breaking off. But none the less... light the fires baby.​

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[Swifted]

I'd be worried about the fins breaking off. But none the less... light the fires baby.​

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View attachment 640842​

The parachute is attached to the fin can so the nose cone should hit first. The fins are 1/8" ply so they at least have a chance of hanging on, but he are definitely going to break at some point.

 

[lakeroadster]

The parachute is attached to the fin can so the nose cone should hit first. The fins are 1/8" ply so they at least have a chance of hanging on, but he are definitely going to break at some point.

I'm talking about fin flutter snapping the fins during flight.​

 

[Swifted]

I'm talking about fin flutter snapping the fins during flight.​

Gotcha, I hadn’t thought of that. It pretty much only flies on c motors, so would those velocities really cause any flutter? Really only built it to mess around in the yard, altitude seems to be about 100ft.

 

[lakeroadster]

Gotcha, I hadn’t thought of that. It pretty much only flies on c motors, so would those velocities really cause any flutter? Really only built it to mess around in the yard, altitude seems to be about 100ft.

Light the fire... ​

 

[Swifted]

Light the fire... ​

I really am trying to learn what works and what doesn’t, definitely don’t want to do something unsafe just because I think it looks cool. A lot of the rockets I will be building are things to look fun from a 5 year old’s perspective, since it’s a good way to keep him interested and learning how things work.