New scratch build: Bomber Betty

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Got the tee-nuts installed in the aft centering ring, and sanded the rail button blocks flush. I also marked the fin slots. Those wrinkles are bad,
but I don't know if they're bad enough to warrant buying another $50 body tube. I don't think they'll cause any structural weakness, especially with the added strength from the motor mount and fins.


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I had a length of 38mm Blue Tube motor tube leftover from something, so I decided to use it. I got the forward centering ring epoxied to it, and the motor mount epoxied into the body tube.

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Finally got the fin slots cut. That LOC airframe is some thick stuff. I need a better knife. I also sanded the fins a little bit, the tabs weren't quite long enough.

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Yeah, Bluto has become Popeye without spinach. He's still sitting here in my garage, getting dustier and dustier, and I see him everyday. But I'm at the point where I prefer big dumb rockets. I just have no desire to mess with electronics, other than the Chute Release. My original goal with Bluto was to have two air started H motors (which means a timer), and a central K. I do have the timer and two altimeters for him, but when I started installing the altimeters, I got a little overwhelmed. Plus, I'd have to create a compartment for the timer. Then there are the shear pins and ground testing. I just don't have the energy or desire for it all. I've thought about simplifying things and launching it single deploy with the Chute Release, but that would be a lot of volume for motor deploy. I know I could easily add BP if needed, and ground testing would be minimal. I've also thought about using air starts with motor deploy (I really like the idea of the air starts). And then there's the cost of the motors. One K and two H's would be at least $160, and that's for one flight. I do already have the motor hardware, though.

So yeah, he still sits in my garage.


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Got the fins epoxied on. You know, that fin alignment guide has got to be the best thing I ever made for rocketry. It has really served me well.
I also got the internal fillets done, and started on the external fillets.


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I had to make another centering ring and the baffle, both to fit inside the coupler.

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I drilled the vent holes in the baffle with a 1/2" Forstner bit.

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I drilled the holes in the baffle for the 5/16" u-bolt, and made the backing plate out of 1/8 x 2" aluminum bar. I'll have to trim the plate a little bit.

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Yeah, Bluto has become Popeye without spinach. He's still sitting here in my garage, getting dustier and dustier, and I see him everyday. But I'm at the point where I prefer big dumb rockets. I just have no desire to mess with electronics, other than the Chute Release. My original goal with Bluto was to have two air started H motors (which means a timer), and a central K. I do have the timer and two altimeters for him, but when I started installing the altimeters, I got a little overwhelmed. Plus, I'd have to create a compartment for the timer. Then there are the shear pins and ground testing. I just don't have the energy or desire for it all. I've thought about simplifying things and launching it single deploy with the Chute Release, but that would be a lot of volume for motor deploy. I know I could easily add BP if needed, and ground testing would be minimal. I've also thought about using air starts with motor deploy (I really like the idea of the air starts). And then there's the cost of the motors. One K and two H's would be at least $160, and that's for one flight. I do already have the motor hardware, though.

So yeah, he still sits in my garage.

Bluto, not Brutus...I’m old and forget details and other things like...um...never mind.

Not often you see an av-bay the size of a water heater.

And you would probably need a full fledged retrieval crew to haul Bluto back to the truck.
 
Bluto, not Brutus...I’m old and forget details and other things like...um...never mind.

I'm with you on that one, brother.

Not often you see an av-bay the size of a water heater.

It does have quite a bit of volume.

And you would probably need a full fledged retrieval crew to haul Bluto back to the truck.

Naw, Olga is tough. She's ex-KGB and even carries a switchblade. She could carry Bluto.

I actually did some playing around with sims. He would hit about 2000' on a K456 Dark Matter, and about 2600' on a K550 White Lightning. Both motors are $113. Like I said, I do already have the hardware, except for a forward seal disc. The K456 needs the disc, the K550 does not.
 
Enjoying watching this one! Love Bertha / Betty upscales. Want to make my own but the nose cone is a killer.
 
No, I won't have Betty ready in time. I'll have to wait until January. I will be launching Thump In My Down, though. His first flight.

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Finally got some work done on Betty. I installed the centering ring in the coupler, and covered the u-bolt nuts with epoxy. Then got the baffle epoxied in.

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Yeah, Bluto has become Popeye without spinach. He's still sitting here in my garage, getting dustier and dustier, and I see him everyday. But I'm at the point where I prefer big dumb rockets. I just have no desire to mess with electronics, other than the Chute Release. My original goal with Bluto was to have two air started H motors (which means a timer), and a central K. I do have the timer and two altimeters for him, but when I started installing the altimeters, I got a little overwhelmed. Plus, I'd have to create a compartment for the timer. Then there are the shear pins and ground testing. I just don't have the energy or desire for it all. I've thought about simplifying things and launching it single deploy with the Chute Release, but that would be a lot of volume for motor deploy. I know I could easily add BP if needed, and ground testing would be minimal. I've also thought about using air starts with motor deploy (I really like the idea of the air starts). And then there's the cost of the motors. One K and two H's would be at least $160, and that's for one flight. I do already have the motor hardware, though.

So yeah, he still sits in my garage.

Really like fin design on this bird Jim.Can't wait to see those pictures of the launch.I agree with the cost of high power motors plus the hardware $$$$$$$$$$
 
For years I've used pieces of ABS pipe to set the position of bulkheads, and keep them level. Cutting them square has always been an issue for me.
I finally figured out that if I use couplers, the ends will be square regardless if the ends of the pipe aren't quite square. Using that method, I epoxied the bulkhead in at 12" from the top.


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For years I've used pieces of ABS pipe to set the position of bulkheads, and keep them level. Cutting them square has always been an issue for me.
I finally figured out that if I use couplers, the ends will be square regardless if the ends of the pipe aren't quite square. Using that method, I epoxied the bulkhead in at 12" from the top.

Great idea! Took looking at the photo for me to understand what you were saying (I am also just getting started on the first cup o java....)
 
I realized that it's the sides of the pipe that keep the couplers square, not the ends.

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Using the retainer to set the depth, I got the aft centering ring epoxied in. And using JB Weld, attached the retainer.

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