Rocketman Enterprises - ThunderChicken

Contributed by Randy Ashley

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Rocketman Enterprises

 

Rocket PicBrief:
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 shock cord 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 "booster" tube is 36 inches long. The second "payload" tube is 8 inches in length. Both tubes are made from Non-brittle, PML Kraft Phenolic.
  • The nose cone is 9 1/2 inches in length and ogive 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 through-the-wall 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 body tube 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 rail 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 od 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 configuration to this point.

PictureFinishing:
Finishing the Thunderchicken was straight forward. I filled all the spiral grooves with Elmers wood-filler and applied 2 coats of primer, 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 out of 5

Rocket PicFlight:
Prepping the Thunderchicken is a little tricky with the extra shock cord that I added. It makes for a tight fit with the wadding and chute. Since I am using altimeter deployment it requires placing the ejection charge 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 altitude according to my Olsen M2 altimeter was 1026 feet. No wobble and very little weathercocking 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 reefed 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 out of 5

 

 

 

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