Complete Sept 20 update Azimuth- a BT-50 cut tube fin Horizontal Spin Recovery Rocket

[BABAR]

Tubes


mass

hmmm, looks like I am gonna need either a 24mm mount (easy enough, just makes it it min diameter, or a Quest D or and Estes C5-3.

 

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Gotta love 6 tube tube-fin rockets. Alignment super easy. Just glue the pairs, laid flat.

like The Horizon, these tubes are slightly larger than the BT-50, but I think it will be a minimal fudge factor.

 

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Sanding off the glassine for area of tube fin attachment. Mylar tape on end to remind me to leave space for external tape wrap.

 

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Fins on. Heresy of mixing glue. Epoxy is used to glue plastic tubes to plastic tubes and plastic tube pairs to cardboard tube. Using white glue for fillets of plastic tube to plastic tubes. Probably a bad choice , as cuts are going to go adjacent to theses fillets.

paper straw launch lug is glued with white glue.

 

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Couplers made of heavy paper rolled from Estes rocket front pages. Also a mylar tape protector, this will protect the tubes, as the rocket will have three sections, 18” each, plus nose cone.

 

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Launch lug with a piece of plastic tube stand off, for middle tube. These extra long rockets need ((IMO) two lugs, as the wind blowing while this is on pad will create a destructive torque with a single tailward lug. But if you put a single lug at the CG; you have already used much of your rod.

good thing is, with separate sections you can line them up easily.

 

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taped on nose cone with vent hole

 

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First cuts at the joints


rough cut

 

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mass cut out

does not include a lot of chaff. Also doesn’t EXCLUDE the exposy and white glue.
i am wondering if I should have used plastic cement, probably would have fused the parts and sanded better.

 

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post clean-up. Well, sort of.

lessoned learned (this is my second with plastic, previous versins were cardboard body tubes, but same problem.)

the external fillets are worthless, as the cuts are too close and the glue probably isn’t holding much anyway. Need to be generous with the epoxy during first attachment of plastic (or other material) tube pairs to the main tube.

i COULD try to put polyurethane glue in the notches, but that would get pretty messy. Anyway, what I did on this one seems to be holding pretty well. I am gonna cover the gaps with Mylar tape.

 

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covered with tape. Used three consecutive greens, three consecutive reds. If @Dotini ’s friend wants to calculate rotation rate maybe this will help.

 

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Azimuth, Beyond the Tube Horizon, Corkscrew* (Bruce Levison design), and Easy Chopper




Corkscrew credits below.

*http://modelrocketbuilding.blogspot.com/2011/03/corkscrew-2-build-backstory.html

 

[jqavins]

Launch lug with a piece of plastic tube stand off, for middle tube. These extra long rockets need ((IMO) two lugs, as the wind blowing while this is on pad will create a destructive torque with a single tailward lug. But if you put a single lug at the CG; you have already used much of your rod.

To avoid that torque, the lug would be at the CP, so not using up as much of the rod as it would at the CG. But I agree with the two lug answer anyway.

i am wondering if I should have used plastic cement, probably would have fused the parts and sanded better.

That depends entirely on what "plastic cement" you mean, and what plastic the tubes are made of. Tester's red label is solvent plus polystyrene filler, so it works where 1) the solvent is effective on the work pieces and B) the work pieces are compatible with polystyrene after the solvent evaporates. Both conditions are obviously met when the work piece is polystyrene, which is what the stuff is meant for. With anything else, it needs testing. The story will be similar with other glues meant for other plastics (e.g. the stuff for PVC pipes).