Acme Little Giant
Parachute Duration
For Micro Max Motors
by Jody Dorsett
This is a very interesting model to build. You will need the following
parts:
1 Hand rolled 4mm BT 80mm long (see Tips) or use a TT-MM BT from
Aerospace Speciality Products
1 10.5 Apogee ST 70 mm long
1 10.5 mm Apogee Balsa Ogive Nose Cone
1 Transition 4mm to 10.5mm (make yourself)
3 Fins cut from 1/32" Balsa They measure 7/8" at root,
3/8" at tip and are 13/16" long
1 launch lug 10 mm long (cut from plastic ear swab, see tips)
1 Motor mount for Micro Max (see tips).
1 Parachute
Building the Model Cut the parts to size. Cut the fins. The hard
part is the transition tube. Find the center of an Apogee 10.5
bulkhead. Drill the center and glue in a 1/16th in dowel. When it
dries cut the dowel to about 1 1/2" from the end of the wood. Chuck
it into the drill. Use sand paper, NO BLADES!!!, And shape the
transition piece. Then slowly twist out the dowel. Use a drill
bit that is not in the
drill motor, hold it in your hand, and hollow it out. Basically you
use the drill bit like a saw. Then glue it between the two tubes.
A drill motor that is used as a lathe Join the 10mm tube to the transition
section. When you glue this, slide the shock cord alongside the
transition section so that when you glue the 10 mm tube to the section it also
glues the shock cord. There is no room for an Estes style mount.
Then glue the tt-4 on the bottom. The fins use a standard 3 fin
alignment. I use very thin sacks from the produce department for the
parachute.
This is a picture of the Mk II. It has four fins that are a plywood and
balsa composite. See the launch report for more detail. The link is
at the bottom of the page
My advisory board: Bart and Sweetie
Acme Little Giant PD Launch Report
The great thing about this model is that it fits right on the MM launcher!
The inspiration for this came as a result of a discussion during the September
meeting of NWARS. We were discussing the MM motor and having contest
built around it. I had played with the concept of the PD model. So
I went home and finished it. The first flight came at the October,2001
launch.
Everyone was impressed by the altitude. The parachute, a 4" for this
test, deployed. The flight was not as straight as I would like, and I believe
this is because it does not have enough fin area. Upon recovery though I
noticed that the fins had cracked along the grain. The 1/32" balsa
was too soft.
Improvements: The ALGPD MkII
For the next launch, I removed the three fins and made four composite
fins. I did this the expedient way of cutting out four fins from
1/64" plywood,and then CAing them directly onto a sheet of 1/32"
balsa. A few minutes later I cut them out! They are very strong and
still light. I mounted them in the conventional manner.
Dec 15th launch:
The four fins did the trick, the model boosted very straight and deployed the
chute. One of the shroud lines broke, surely because the model had not
yet reached apogee! Too bad the delay is so short on the MM motor.
None of the flight pictures worked, but here's a picture of it loaded on the
pad for its second flight of the day. Another great thing is that these
little models are perfect for the 5 acre park in my small town.