Kicking Horizontal Spin Up a Notch-- 2 Stage

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BABAR

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Should work great for non-gap booster, first time I have tried it for booth.

Pre cut shots

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BABAR

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First and second cuts.

Goes quick with scissors.

You can see the ridges. After CA will be used to harden the fins, Dremel Sanding barrel will be used to smooth these down.
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BABAR

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This will be nongap staging, so motors will be taped.

I did this for two reasons.

1. Since BOTH stages are horizontal spin, I felt if the booster was too long i could not use as much fin surface area as needed for the SUSTAINER to also work with horizontal spin. Interestingly, a horizontal spin recovery booster with long gap stage would work extremely well with a dedicated NON-spin Back Slider, as the Back Slider has small rear fins and a very long body tube..

2. I am close to minimum length on the booster, basically the length of the motor. I am recessing the booster motor about 9 mm into the tube (about 1/2 the internal tube diameter) to avoid Krushnic effect, which as I understand it occurs when you exceed 1 tube diameter. So only 9mm of the motor sticks out the front. The sustainer motor will also be recessed 9mm. Even for a booster this short, for a SUSTAINER that long I didn’t think 9mm minimum diameter rocket motor coupling ALONE would be enough, UNLESS the motors were taped, in which case it’s pretty much 60 mm coupling into each end, which should be rock solid.

the FUN part is going to be friction fitting the sustainer motor, and the REALLY fun part is going to be getting that motor OUT.

NOW THAT I think of it, I think I am going to CUT the sustainer tube 1/2 inch ABOVE the fin can, wrap the adjacent ends in Mylar tape to protect the underlying body and paint, and use a coupler which will also serve as a motor block for the recessed Sustainer Motor, I will place it after I test fit the taped casings to get the right depth. It then becomes easy to put the sustainer fin can coupler into the sustainer body tube, use a second layer of tape over the first to hold the two together in flight. Post flight, take off the outer tape, pull the sections apart, and Bob’s Your Uncle I can just use a dowel from the front to shove the recessed sustainer out the back.

not sure what happened to pics

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Dotini

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@BABAR
Do you do a fair amount of work with a Dremel? I occasionally feel the need of one, so can you recommend any particular Dremel model and accessory tools that I might purchase? I always appreciate your advice.
 

BABAR

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@BABAR
Do you do a fair amount of work with a Dremel? I occasionally feel the need of one, so can you recommend any particular Dremel model and accessory tools that I might purchase? I always appreciate your advice.
I use the term Dremel, I actually have this from Black and Decker, but it uses Dremel and knock off accessories. Since I have never used any other kind (including the real Dremel!) I really can’t make a recommendation, except that this has worked fine for me.

If you are looking for recommendations, might be a good question to ask on the Beginner or even Watering Hole forum. Or take a chance and buy whatever is cheapest at Harbor Frieght or Wally World.

I have had this for years, it does quick work at think that otherwise would take a while. i WILL say that for this latest build, I tried sandpaper and an Emory board and they wouldn’t touch those glued ridges on the tubes (remember, they were first glued with wood glue and hardened with CA.) Without my Black and Decker (assumed Dremel Equivalent) and the small barrel sander adapter, I would have given up and left the ridges.

if you use the cutting wheels, DEFINITELY wear safety googles, the ceramic wheels sometimes shatter.
 

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BABAR

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Definitely get the cutting wheels and the small and large barrel sanders
 

BABAR

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Decided if I was going to cut a piece out of the body tube I would give myself a handle length to hang on to.

(
16178429732634607403438792364887.jpg

And for the peanut gallery, the Band-Aid had nothing to do with model rocketry and I am expected to make a full recovery!)
 
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mbeels

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and Bob’s Your Uncle I can just use a dowel from the front to shove the recessed sustainer out the back.
Just love that saying, it doesn't get used enough.

if you use the cutting wheels, DEFINITELY wear safety googles, the ceramic wheels sometimes shatter.
And for the peanut gallery, the Band-Aid had nothing to do with model rocketry and I am expected to make a full recovery!)
Oh? 👨‍⚕️
 

BABAR

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Just love that saying, it doesn't get used enough.
first heard it in Mary Poppins.

Dick VanDyke was great in that movie. Chim Chimney still one of my favorite songs, has a happy but haunting quality


 

Rktman

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BABAR

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Great thing about your tube fin design is that it'll spin the rocket on the way down, but not on the way up (which decreases altitude).
Yup. My hope is that these will backslide with a much shorter length than required for typical backsliders, which are near SuperRocs.

the 6 fin design is looking to be very sturdy.
 
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