Saturday, April 11, 2009

Building update

After a short building hiatus due to this whole 'life' thing - apparently some trippy experience involving schoolwork, tennis, paid work, little sleep, etc - I did some building on the Nantucket Sound and other miscellany.

I've got most of the guts of the Sound done - all 4 supports plus the launch lug and its two supports are attached and the first round of fillets drying. I cut the four fins and sealed them with plastic cement (surprisingly effective), although the one I did with actual wood sealer is a bit smoother. Now all I've got to do is do the second and third rounds of fillets, glue and cut the main shroud, cut the lug to fit the shroud, glue and paint the fins, and attach bits and pieces like the elastic part of the shock cord and parachute. I hope to finish it by Sunday night, although I do have all of next week off for spring break. It's gonna be a heavy, draggy beast, so I'll go for a 24/40 E18-4W reload and two chutes - 12" for the nose unit and 16" for the boddy to avoid damage. Jim Flis didn't provide composite motor recommendations for it, but I think the E11-3J, E18-4W, E28-4T, F12-5J, and F24-4W will be good fits for the 24/40 casing and E15-4W, E30-4T, and F32-4T for SU motors. The D15-4T and F39-6T have too long of delays but would work in a pinch, but the D9-4W has a too slow buildup of thrust to work at all. I f you really wanted it to rock, then a 29mm motor mount and Econojets and the 29/40-120, 29/60 29/100, and 29/120 casings would fit. Barely. It really would rock on a G80, though. *Evil grin*

I'm trying to build a super-strong bulkhead with integrated screw eye that'll survive even the worst shotgun ejection charges without having to buy and cut plywood. I'm filling an 18mm connector tube with wood glue, about 1/8" at a time, letting it dry between gluings. The screw eye is supended in the glue and will be solidly encased by it. The bulkhead will be absolutely solid, absolutely heatproof, and pretty well indestrctable, but heavy and difficult to make. Worth a try though.

I had to take my Comanche-3 down from its ceiling mount - the single hanging point was causing it to bend, and bent superrocs are not good. I don't think it's suffered any permanent damage, fortunately. It's probably not a good idea to hang any rocket onger than 18" or so froma single point. Normally, I have the Comanche-3 resting on its fins on an old office chair and supported by the chair about 14" up it length. The mandachan! sits above my desk on 3 pegoard hooks, but it's light (under an ounce), evenly balanced on the three hooks, and fairly strong because the 13mm tubing is fairly thick for its small diameter - the same thickness as other estes-type tubing us to BT-80 size.

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