From: mckiou@cbnewse.cb.att.com (kevin.w.mckiou)
Newsgroups: rec.models.rockets
Subject: Astro-Blaster Mod
Date: 9 Sep 92 19:41:53 GMT
Organization: AT&T

I recently had the opportunity to fly an Estes Astro-Blaster and even
modify it to perform better.  Here's some of my experience.

The Astro-Blaster is basically set up to fly hands-off on boost - well
sort of.  You are told to set the trim for a flat glide and launch it
with that trim.  The AB I flew was indeed trimmed like that.  Actually
it boosted pretty straight under power.  But, as soon as the motor stopped
thrusting it REALLY pitches back.  It even looped the first time. I think
the reason for this behavior is a CG that is really too far forward. It
is quite sluggish in pitch when flying and the nose/canard will mush
if you try to bank it into too tight of a turn.  I really think
there is a lot of room to move the CG back and change the trim of the 
canard so it does not pitch up after motor burnout.  Of course, the
reason it is not pitching up under power is the fact that the thrust
line is WAY above the CG.  So, if you move the CG back, move the thrust
line closer to the CG.  This will help both boost and glide performance.

Now, how do I know you can safely move the CG back?  I (and a couple
of fellow RCRG flyers) added a pair of BT-20 "strap-on" boosters to the
rear of the fuselage (with big red pointy nose cones - kind of like
the tail lights on an old cadillac).  The AB we were flying is exceedingly
light (for an AB) at 12.5 ounces glide weight.  Yet, the performance
on a D11-P leaves you wanting MORE after flying it a couple of times.  We
put a pair of C6-5s in the strap-on boosters and air-started them with
themalite.  What a difference!  Instead of lumbering up about 250 feet
on a D11, it RIPPED to about 400 feet.  The 3 flames out the back were
really neat too.  Plus, the boosters add just the gaudy touch that makes
it live up to its name :-).  Oh, don't worry about it yawing if only
one strap-on lights.  The affect is minimal - mostly just less altitude.
BTW, we let the C6s eject for more flight time.  Though, I don't think
it really made much difference. You could vent the ejection - or - 
violate the safety code and remove the ejection charge (oops!)

If you really want to make this thing cook, try an E15.  I haven't, but
I bet it would have no trouble taking the  loads.  It seems to really
like more power.  Certainly the fuse and wings are strong enough.  The
canard also looks plenty robust - but you never know until you try.

BTW, D11/C6/C6 cluster gets more altitude than an E6.  I seem to remember
that the sustainer thrust in the E6 is only 16 oz.  So I guess this
result is not surprising in retrospect.

After recently seeing the video of Star Trek VI and then seeing the AB
in flight, I immediately knew what they should have named it - Bird
of Prey.

This is really a fun ship to fly.  You can start out rather conservatively
with the D11-P - and then -  add power until you run out of nerve!
What a kick!


Kevin

---------------------------------------------------------------------
Kevin McKiou                         UUCP:     att!ihlpm!kwm
NAR 51581
AMA 380751
AT&T Bell Labs, Naperville, Ill      Internet: kwm@ihlpm.att.com
---------------------------------------------------------------------