Vintage Build: Microsonde III

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Two 13/18 adaptators have been built. Because of the couplers between stages and the way they stack I had to build them special for each stage.

Should be able to launch all three stages at the next club launch, assuming I can find some A10T-0 motors.

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Two 13/18 adaptators have been built. Because of the couplers between stages and the way they stack I had to build them special for each stage.

Should be able to launch all three stages at the next club launch, assuming I can find some A10T-0 motors.

View attachment 429768

They look workable. Is the middle section of each adapter necessary? What do they weigh?

Hope you get a great flight!
 
I finallllly got some A10-0Ts. So this is going up on Saturday,, assuming the winds are reasonable. C6-0 -> A10-0T -> A3-4T.

Every possible thing on this rocket is friction fit, which is nerve wracking, but we'll see if my skills are up to the challenge.
 
And I *still* haven't launched mine - school been so busy lately I haven't had the chance. Perhaps this weekend.
 
Ok, so I finally launched this. It was uh, not that great. The first stage went fine (see launch below), but the 2nd and sustainer stages (the 13mm engines) *both* ejected out the back! The first stage separated and recovered fine. The sustainer was found as a lawn dart (see below) with the middle stage still attached. Despite these foul ups, it still managed an apogee of around 500 ft, measured via my FlightSketch.

Some re-engineering is clearly in order. Or I may just hangar queen this thing.

Here's slow-mo video of the launch on the B6-0 lower stage, which went well:


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Tighter fit for your second and third stage motors.
Looser fit for the second to third stage coupler.
Also make sure the transition is not on too tight.
Sand down the shoulder perimeter if needed.
 
Ouch! Hope it’s repairable.

I hope you can get one good three stage flight with a safe recovery before she retires to the hanger!
 
I was doing autopsy on the Microsonde when I realized an obvious design flaw and wondered how I missed it before:

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The base for the payload pay (where the shock cord attaches) has a hole in it. The ejection charge gases can vent right into the payload bay, and where they can then pop the nosecone off. Remember this is a minimum diameter kit from the 1980s; the nosecone is entirely friction-fit.

So, yeah, that's a problem. It helps explain why the chute never deployed during my previous launch. I decided to fix this issue using some Fix-It epoxy clay, which I was able to jam inside to make a seal, without reducing the space for hooking the shock cord on.

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