||12" plastic parasheet w/ spill and vents
||This was the usual perfect flight for the Bertha -- there's never been,
and likely will never be a more reliable model. Unfortunately, on
recovery, I noticed a crack in the fillet on one fin root -- these fillets
are Elmer's Fill 'n Finish over white glue structural fillets -- and on
careful inspection, found five more cracks out of eight fillets.
This isn't a huge problem, but requires that I wick some thin CA glue into
each fillet to reinforce it before flying again.
||18" nylon parasheet
||The packaging states that the Spike can be flown on D through H motors
-- and I wanted to try out the lower end of that power range. I found
that the claims are true; you can get a safe flight on a Spike with a D12
motor, providing you didn't use too much epoxy in construction. In
my case, I used only yellow glue, and the 3rd centering ring I added was
a fiber stuffing ring; as a result, my Spike is on the light side despite
the one ounce penalty for the Universal Motor Retention System. The
altitude was low, but that's to be expected with a 12+ oz. rocket on a
D12 . . . and there was certainly no problem with recovery.
||18" nylon parasheet
||This was the second motor from the same pack as the one that gave such
good results in Kent on 11 October; unfortunately, this one must have been
less carefully made; the forward bulkhead blew out of the casing, taking
the burning delay element and intact ejection charge with it. The
good news is, in western Washington this time of year, you couldn't start
a grass fire with thermite; the further good news is that the nose cone
and recovery system simply got out of the way without damage; the final
good news is that the propellant extinguished from the sudden pressure
drop. The rocket body never left the pad, though the nose cone implanted
itself in the soft ground after springing back from the end of the shock
cord. Net damage: none. I'm in negotiations with Aertoech right
now concerning warranty service.
||18" nylon parashheet
||Aerotech E18-4 (RMS 24/40)
||This flight went much better than the last; the igniter lit on the
first try, the motor fired immediately, and the burn profile and delay
were nominal . I think I'll wind up burning a lot of these reloads
in this rocket; it makes for a very pleasant flight, for less cost than
an Estes D12. I may also look around for some of the D15 load for
this case; the extra 3 Ns (compared to the Estes tested value) couldn't
hurt, and a little more thrust would be welcome; plus, these loads are
even cheaper than the E18s.