RodRocket
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- Sep 10, 2011
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So to not take over 808rocketmans thread I am starting a build of a 2 stage D to D rocket I'm calling DMD2.
The concept is bare minimum build, try a different, to me, coupling technique, small thin fins, minimal parts count and see what happens.
So far have the body tubes cut, sustainer is 370mm, booster is 92mm white 24mm ID paper tubing wall thickness is maybe 1/2 mm.
Glued booster thrust ring at aft of tube, while that was drying I notched the other thrust ring to tie a kevlar cord to. I guessed at the kevlar length, maybe 6 ft total.
Then I took a spent D case and slipped it into the booster followed with another D case. Ran the cord through the ring and both cases and out the bottom to keep out of the way and stacked the thrust ring on top. Took a quick skewer measurement to locate the glue area for the thrust ring and applied the glue inside body tube, then slid the stack into the tube and pushing the ring into the glue. Then quickly but carefully pulled the cases out and left to dry.
Pulled the cord back through the body tube and tied on the cone and a couple inches below the cone tied a simple loop for recovery attachment.
Now I need to visit hobby store to pick up wood for the fins. Think I may try thin aircraft ply this time. And then get to finishing. Hope to have this rocket ready for Kloudburst in April at Kloudbusters pasture in Argonia, Ks.
Going to do tweaks to Openrocket sim file below. Going with a nose cone I already have, and changing position of fins on booster. May even change their shape a bit, worried that the tapered fins will let the booster stabilize and not tumble during decent. Will be sure to let everyone know of that possibility before launch. Really only one way to find out what will happen. Build it and stick in a spent case and give it a toss in the yard.
Not a difficult build at all. And with minimal parts will be really light. Minimal standard left over Estes launch lugs, 1/4 inch long at body and tapered ends.
This rocket is gonna scoot on D's! See no reason why it wouldn't fly well with adapters to fly 2 C's or a D boost to a C for smaller fields. Will have to sim those to see what happens.
I'm gonna John Force it with D's for the first launch. Win the race or blow it up trying!
See ya,
Rod
View attachment DMD2 min dia 2 stage D engines.ork
The concept is bare minimum build, try a different, to me, coupling technique, small thin fins, minimal parts count and see what happens.
So far have the body tubes cut, sustainer is 370mm, booster is 92mm white 24mm ID paper tubing wall thickness is maybe 1/2 mm.
Glued booster thrust ring at aft of tube, while that was drying I notched the other thrust ring to tie a kevlar cord to. I guessed at the kevlar length, maybe 6 ft total.
Then I took a spent D case and slipped it into the booster followed with another D case. Ran the cord through the ring and both cases and out the bottom to keep out of the way and stacked the thrust ring on top. Took a quick skewer measurement to locate the glue area for the thrust ring and applied the glue inside body tube, then slid the stack into the tube and pushing the ring into the glue. Then quickly but carefully pulled the cases out and left to dry.
Pulled the cord back through the body tube and tied on the cone and a couple inches below the cone tied a simple loop for recovery attachment.
Now I need to visit hobby store to pick up wood for the fins. Think I may try thin aircraft ply this time. And then get to finishing. Hope to have this rocket ready for Kloudburst in April at Kloudbusters pasture in Argonia, Ks.
Going to do tweaks to Openrocket sim file below. Going with a nose cone I already have, and changing position of fins on booster. May even change their shape a bit, worried that the tapered fins will let the booster stabilize and not tumble during decent. Will be sure to let everyone know of that possibility before launch. Really only one way to find out what will happen. Build it and stick in a spent case and give it a toss in the yard.
Not a difficult build at all. And with minimal parts will be really light. Minimal standard left over Estes launch lugs, 1/4 inch long at body and tapered ends.
This rocket is gonna scoot on D's! See no reason why it wouldn't fly well with adapters to fly 2 C's or a D boost to a C for smaller fields. Will have to sim those to see what happens.
I'm gonna John Force it with D's for the first launch. Win the race or blow it up trying!
See ya,
Rod
View attachment DMD2 min dia 2 stage D engines.ork
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