> Hi There.
> Okay -- I purchased a LOC Onyx kit and have already begun to assemble
> it (the engine mount is already glued in). Contrary to most LOC
> kits, this one doesn't use through-the-wall construction. Instead, it
> uses surface mounting for it's fins. I heard someone mention using
> "Epoxy Rivets" to increase the strength of the bond between surface
> mounted fins and the body tube.
> Can somebody describe to me the technique in detail?
Actually, if you just sand off the body tube gloss in the area of the
fin with 100 grit and use reasonably-sized 30-minute epoxy fillets (with
or without glass or graphite "whiskers") you should be fine for anything
up to an H238. I have an Onyx and it flies great! I did add 1/2 oz. of
lead to the nose cone just in case I want to fly it with an H97 someday.
> Also, since I've already installed the engine mount in the rocket, I
> can't setup a nut-and-bolt type of engine retention system. As an
> alternative, I was thinking of screwing in two "eyelets" on each side
> of the engine mount, and use a strong piece of wire, wrapped through
> the eyelets and over the shoulder of the engine (without obstructing
> the nozzle) to hold the engine in place. Has anybody used this
> technique before? And does it work well?
I've used safety wire, but it gets bad reviews with most RSO's. You can
still put a T-nut in the centering ring. Just drill a hole big enough
for the center stud to fit into and carfully drive the T-nut in from the
outside. Install a bolt, then add enough epoxy to cover over the entire
T-nut (You'll need very little epoxy if you make sure the T-nut is all
the way in). If you want, you can lighten the epoxy with glass
microspheres, just make sure that the viscosity stays low enough to
"flow". When the epoxy is almost but not yet completely hardened,
remove the bolt. Voila.
"Great discoveries and improvements invariably involve the cooperation
of many minds."
--Alexander Graham Bell