Tube coupler fit

[STRMan]

I've been in the process of building a Centuri Stiletto 2 stager from Semroc parts. I'm just about ready for paint.


http://i85.photobucket.com/albums/k65/STRMan/Mar08_0001.jpg


My question is how tight should the booster section fit to the sustainer section? It seems like these fit pretty tightly together. Is there an accepted description of how tight this junction should be? I've been trying to sand the inside of the coupler down a bit by wrapping and taping an engine with 400 grit sand paper and twisting it inside the coupler. So far, it has helped a bit, but I'm wondering if anyone has any other thoughts on this issue. Would graphite powder possibly help?

[Rocket Doctor]

I've been in the process of building a Centuri Stiletto 2 stager from Semroc parts. I'm just about ready for paint.


http://i85.photobucket.com/albums/k65/STRMan/Mar08_0001.jpg


My question is how tight should the booster section fit to the sustainer section? It seems like these fit pretty tightly together. Is there an accepted description of how tight this junction should be? I've been trying to sand the inside of the coupler down a bit by wrapping and taping an engine with 400 grit sand paper and twisting it inside the coupler. So far, it has helped a bit, but I'm wondering if anyone has any other thoughts on this issue. Would graphite powder possibly help?

The best description I can give to you is snug, but, not tight. The two stages need to seperate without friction. It's a sand alittle , try it, and sand alittle more. Just don't make it too loose, snug.

[Commanche3]

That's an awesome bird, I just got my parts in from Semroc for a FS Megatron clone. I 'm in the process of building an old Estes Sea Strike D.


Multi Stages Rock
Kevin

[MKP]

The rule of thumb that I've used is the booster (with engine installed) will stay attached when held upright, but will fall off if given a good shake. It's always worked for me.

And, yes, graphite power does work. Saw a tube of the the stuff, looked at my Quest Navaho and had a "I wonder..." moment. :)

[PaulK]

I've been in the process of building a Centuri Stiletto 2 stager from Semroc parts. I'm just about ready for paint....
My question is how tight should the booster section fit to the sustainer section? It seems like these fit pretty tightly together....Cool. My Stiletto from the same parts also started out very tight. I did a fair amount of sanding on the inside of the coupler with 400, and a bit on the outside of the sustainer; it is still tighter than I would like, it certainly will not fall off on a good shake; but the first flight staged fine (A8-0 to A8-5), and now it is repaired for an upcoming 2nd flight. What kind of shock cord & mounting are you using? I *wish* I had mounted some kevlar to the engine block.

-Paul