
(Contributed - by Randy Ashley)
Brief:
My Level 1 rocket, single stage, single deployment, altimeter deployed
parachute.
Construction:
Building was very basic. The instructions that were included were not for this
rocket. Ky had just released this kit and did not have a set of instructions
for it at the time I purchased the kit. However even though this was my first
high power kit I had no problems with construction. Assembly was very intuitive
and parts fit was precise. Ky made the comment to me if you have built any
Estes kit you will have no trouble with the Thunderchicken, and he was correct.
I used epoxy throughout. I felt that the included was too short so I
added 10 feet of 5/8 inch tubular Kevlar®.
A few highlights regarding the kit compnents:
- There are two body tubes. The main "" tube is 36 inches
long. The second "payload" tube is 8 inches in length. Both tubes are
made from Non-brittle, PML Kraft .
- The nose cone is 9 1/2 inches in length and in shape. It is made from
plastic.
- The very one-of-a-kind shaped fins are made from G-10 fiberglass, about
3/32 inch thick and are mounted to the motor mount. I used 30
minute epoxy on all attachment points. I glued them through the wall to the
motor mount, then filleted fin to motor mount, fin to inner of and
lastly fin to outside of body tube with generous fillets.
- The included launch lugs appeared to be 1/2 inch brass lugs about 2 inches
in length each. However I opted not to use them as I prefer buttons. I
used 2 Blacksky acetal plastic buttons. Both were attached so as to screw
directly into centering rings. One is placed 1/4 inch from the bottom of the
body tube, and the other is placed 12 1/2 inches up from the bottom of the body
tube giving a spacing of 12 1/4 inches between the buttons which is plenty to
give adequate stabilization of this rocket on the rail. The rail used for this
rocket is the 4 foot standard BlackSky rail which is mounted to a pad
of my own design. My pad is designed so that the rail mounts to a 3/4 inch
water pipe. The pipe supports the rail for the entire length. This takes the
3/8 inch mounting stub on the rail out of the situation and now make the
mounting point on the pad the 1 1/16 inch of the pipe instead.
- The centering rings were 3/16 plywood. The finish was excellent and
required no sanding to fit properly. I did however use some 80 grit sandpaper
to rough up the edges to help with epoxy retention. There are 2 centering rings
and the fins are mounted in-between the rings so that the fins are glued to the
motor mount as well as the centering rings and the body tube.
- The shock cord mounts to side of the motor mount tube by epoxying it in
place. It is designed so that it passes through a slot in the front centering
ring. The shock cord has a small gather sewed in about 4 inches from the end
and this gather is below the centering ring. This way there is the epoxy
holding the cord to the motor mount and the gathered portion resting against
the forward centering ring to aid in retaining the shock cord. The stock shock
cord only comes about 1 1/2 feet out the end of the body tube. It is terminated
with a D ring. I tied an extra 10 feet of shock cord to this. I used 5/8 inch
tubular Kevlar® in this application. I use 1/4 inch quicklinks at the nose cone,
chute attachment point and the point where the two shock cords meet. This aids
in disassembly of the rocket and makes it such that storage is easier as the
rocket parts can be stored separately. This was my first higher powered rocket
and in Retrospect I would have probably used an eyebolt or u-bolt instead of
the glue to motor mount method. How ever I have had 100 percent success with
the stock to this point.
:
Finishing the Thunderchicken was straight forward. I filled all the spiral
grooves with Elmers wood-filler and applied 2 coats of , sanding between
coats with 300 grit sandpaper. This was enough to make the spiral grooves
disappear. My final coat was Krylon metal-flake blue. The finish came out very
nice. I did not use the included decal since I went with the blue finish and
called it the Blew Goose. The unique fin shape always draws comments at the
flying field.
Construction Rating:
4
½ out of 5
Flight:
Prepping the Thunderchicken is a little tricky with the extra shock cord that I
added. It makes for a tight fit with the and chute. Since I am using
altimeter deployment it requires placing the in first followed
by wadding, shock cord, and chute. It all fits just fine but requires a nice
tight chute fold. After loading the recovery equipment, I install the altimeter
in the payload section. The Aerotech H128 motor is retained by a couple of
homemade clips with #10 machine screws screwed into tee nuts in the rear
centering ring.
The flight was picture perfect from a BlackSky Rail. The according
to my Olsen M2 altimeter was 1026 feet. No wobble and very little
despite a gusty 15 mph wind.
Recovery:
Rocketman kits come with a very short shock cord due to the VERY soft opening
of his chutes. However it is the force of the nose cone snapping the cord tight
that worries me. This is why I added 10 extra feet of shock cord to the 4 feet
that are included in the kit. The Rocketman chutes are incredible. They open so
soft that the shock on the rocket is minimal. With the altimeter deploying at
apogee the deployment was very soft. The rocket came down a little fast but
this was my fault, as I had the shroud lines some to cut down on the
drift in the high winds. Even though the rocket bounced up about 4 feet on
landing there was no damage to the G-10 fiberglass fins.
Flight Rating:
4
out of 5
Summary:
In summary the Rocketman Thunderchicken is a very well built kit that is easy
to construct. When properly built it will be a tough kit that will take a lot
of punishment and still be there for you. The only thing I feel you should
consider changing on your kits is adding some more shock cord to aid in a soft
deployment.
Overall Rating:
4
½ out of 5