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This is more than awesome, good luck next week! Oliver

Real hardening is only possible with fiberglass IMHO, since all the other stuff, especially epoxy, tends to be brittle and will break while the balsa underneath gives way. It will be a lot of work to finish properly (fill-sand-fill-sand...), but with a single layer of 25 g/m^2 glass all...

Why should there be two pieces? I personally have launched a Comanche-3 to full altitude and was able to track it all the way into the woods ;-) It was painted black instead of light orange, IIRC, which makes it easy to track against both clear and cloudy skies. Since the Comanche is very light...

> If you haven't already laminated your centering rings and fins you might consider a layer of fiberglass (or two) between the two 1/4" sheets of plywood. This will strengthen them incredibly. Should help even more when laminated with FG on the outside. Oliver

> Lager expansion ratio = more efficient = more total impulse Not necessarily, it could lead to overexpansion. Which expansion ratio does Lager have, btw? Is it any different from Pilsener or Hefeweizen? (SCNR) Oliver

Oh yeah! I've been thinking of equipping a rather stiff rocket (fiberglass, alu) with DMS (erm, that's, a... wait... strain gauge) to measure deformation of the airframe and in particular the fins. But that's a ways down the project pipeline... The other thing is I'm looking for a master...

No, but I'd love to see results from a wind tunnel. The truth is somewhere in between, I guess... Oliver

I don't know whether this has been discussed here before, but over at EURocketry we came across an interesting and disturbing fact concerning the stability of rockets with slotted fins such as the Thor design. This is the thread I'm referring to...

You haven't seen the quality of the balsa nosecones that guy makes. They have to be stored in bubble plastic and glassed immediately so as not to damage them ;-) We have a lathe in our aeromodeling shop at Uni, but I haven't gotten around to get myself introduced to that machine (I did turn a...

I think there's not just "the building process". Part of it is planning, which I love to do, part of it is building, which I enjoy if things go right (more detail below), and finish, which I usually don't bother to do. I'm an engineering student and contrary to popular belief I like to put to...

Whoah, that thread is _old_. I certified on the Phobos, but it was lost in very cold weather in Switzerland due to a weak ejection charge in 2002 or 2003. Even though it hit 1.5 m of snow I wasn't even able to recover the nosecone. Only the fins and the parachute made it through. The Phoenix...

Then get some glass. Just lay it on the nosecone, wet it out completely (becomes transparent) with epoxy (e.g. dabbing it with a brush) and let harden. It is actually pretty easy! Oliver

Covering balsa with epoxy doesn't help at all. It responds to the slightest pressure by cracking. Use a thin, say 25 g/m^2, layer of glass and you'll get a rock solid but still very light nosecone. Oliver

I made one of these last week https://www.audiocad.de/u/bauvor/fraeszirkel/d_fz.html and it works great. It's just that you have to figure out which setting gives which diameter exactly before cutting, but you only have to do that once. Oliver

> Based on Estes's estimate of about 312,000,000 launches and assuming an average total impulse for each flight of 7.5 Ns (a C motor), you get about 2.3 Billion Ns. I'd say that's a conservative estimate. With a total of 500 million launches I've read about somewhere and any single M launch...

From the limited choice we have over here in Europe (AT, Cesaroni) definitely White Lightning. Huge white flame, lots of smoke, just awesome! Followed by Blue Thunder, the only other propellant that looks kinda "real". W9 is too fast for me, but from what I heard AT may be making a few new...

I scratch built a 4" Phoenix once and only covered the balsa nosecone in 40 min epoxy. The nosecone has since lost its tip and has several dents. The next balsa nosecone got a covering of very light glass (25 g/m^2) and is now extremely resistant. Something I'd suggest for all balsa cones from...

Where is the original source that says the X-Wing was blown up intentionally when it diverged from its course? Oliver

I'm planning on building a 3-stage MPR rocket (a G80+E30+D12 that is, no idea whether it's MPR or HPR), and I'm wondering whether one of you guys has successfully lit an E30T or similar engine in a rocket's second stage, and if yes, how (power supply, igniter)? Oliver

> Did you have great time at ALRS? We did not go, but plans have already been made to go next year! We're planning on driving down, and combine ALRS with a trip to Italy! ALRS was awesome this year, great people, great flights and perfect weather. Except the hotel still sucks -- they only...