MPC Vostok Build

Here we go again!

The MPC

VOSTOK

build has been started on my build blog at:
www.modelrocketbuilding.blogspot.com

This was an original MPC Fly or Display kit.
I'll present everything needed for the flying version.
It's heavy, who knows if it'll even clear the launch rod.
Lots of twists along the way!

...this excites me.

Cool! I'm looking forward to the build. I would love to find a Vostok to go with my Saturns.

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On Saturday the Vostok went unstable after it left the rod. I used an Estes C6-3.
The attached picture shows the boost right before it flipped end over end.



I had a feeling this would happen but I had to give it a shot.
I'm not going to use a 18mm composite on this one.
I wouldn't waste the money on the engine just to watch it
spin around after leaving the rod.

This model was probably not flyable when it was first released in the 1970s.
MPC mentioned a C9-3 engine on the kit box but I don't think they were ever produced.

I can't recommend any flying conversions made from the Round 2 Vostok kit!

-- Roger

Thanks Roger!
I think that aerial shot says it all.
The spectators all look very tense.

Who says low power isn't exciting?

Looks like Roger's gonna have to wear his hard hat around you too!!

I wonder if another 1/4z of nose weight and an old C5-3 would work? Probably, but not likely too well anyways.

Come to next TTRA launch, guys.....I'm going to pull out all the stops and go insane :y:

Looks like an OOP Aerotech C12 reload might work. By the way, what was the empty weight of the model?

It weighed 4.25 oz. without engine.
Sorry, I'm not going to fly it again!

jadebox said:

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-- Roger

Click to expand...

AWESOME!!!!

I would think an Aerotech D21-4 could probably do the trick, even if you had to add another half-ounce of nose weight for stability.

I build and flew the original in the 1970's and it flew fine. You had the larger flight fins and not the smaller diaplay fins?

Modern Estes C6-3 should have almost the same performance as a 1970's C6-3 so it should have left the rod with just enough speed for the fins to keep it moving in the directionlaunched, UNLESS therer was a crosswind AND the launch rod was a bit short.

If everything was good and it still went unstable, then something odd happened, such as a motor with a damaged nozzle, nose weight off center, or something in the exhaust which deflected the thrust.

shreadvector said:

I build and flew the original in the 1970's and it flew fine. You had the larger flight fins and not the smaller diaplay fins?
Modern Estes C6-3 should have almost the same performance as a 1970's C6-3 so it should have left the rod with just enough speed for the fins to keep it moving in the directionlaunched, UNLESS therer was a crosswind AND the launch rod was a bit short.
If everything was good and it still went unstable, then something odd happened, such as a motor with a damaged nozzle, nose weight off center, or something in the exhaust which deflected the thrust.

Click to expand...

Hi Fred,
I used the larger fins and the nose weight supplied in the kit.
An Estes C6-3 was used, the launch rod was 36" long. Winds were pretty calm under 5 mph.
The original MPC engine hook was used with the finger tab. The hook didn't leave anything in the path of the nozzle.

Who knows? The model was heavy, but not overbuilt.
I wanted to give it a shot.

Do you have the date code of the motor?

Just want to rule out "Poopy Clay" nozzle from 10+ years ago...

I wonder if you could replace the oversized fins with more-oversized clear plastic fins, then paint scale fins onto the clear plastic.

shreadvector said:

Do you have the date code of the motor?
Just want to rule out "Poopy Clay" nozzle from 10+ years ago...

Click to expand...

The date code was A04107
No poopy clay here. The nozzle looks normal.

Thanks for all the suggestions on how to get a stable, vertical flight.
This one won't fly again.
My old MPC kit was a pain to assemble and had a disappointing launch, simple as that.

On to more rewarding projects!

OK doke, I just have ideas about picking up one of the reissue kits and converting it for flight.

This may raise an interesting question: would the reissue qualify as a PMC project because the new version is not intended for flight and does not contain the internal parts necessary to make it flight-capable, or would the fact the original kit WAS intended for flight capability and was manufactured to easily accommodate flight conversion DQ it for PMC competition?

jadebox said:

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"After the embarrassing failure of Vostok I, chief designer Sergei Korolev was reassigned to Siberia, leaving the Soviet space program in disarray....."