Cygnus Rocketry - 76er {Kit}

Contributed by Pete Harper

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Diameter: 1.64 inches
Manufacturer: Cygnus Rocketry
Skill Level: 1
Style: Sport

Rocket PicBrief:
The Cygnus 76er is advertised as a low cost alternative to to the Estes Mean Machine.

Construction:
This kit comes with a balsa nose cone, the body tube is four section of BT-60 cardboard tubing, three couplers, four small pre-cut balsa fins, plywood centering rings and 24mm engine mount. The parachute is plastic with string for shroud lines. 1/8" elastic shock cord. 3/16" launch lug.

The instructions were quite minimal but that was not an issue. This is a simple straight forward rocket to assemble. Anyone who has previous experience building low power rockets will have no problem putting this kit together.

At 79 inches this is a tall rocket. Thinking ahead that I couldn't transport a 79 inch rocket I built mine to separate in the middle at the middle coupler.

I had planned to "turbo" charge my kit so I made the following modifications. The balsa fins were designed to mount to the outer body tube. I traced the pre-cut fins and made through the wall fins out of 3/32" bass wood. I used the marking jig to mark the main body and cut slots in the airframe using a dremel tool. The fins were glued with epoxy to the engine mount similar to many mid-power designs. The engine mount is friction fit with a stop for a maximum of D-size engine. The kit D12 recommendation in my opinion is way under powered for a rocket of this size. RockSim says only 375 feet on a D12. I left out the D-engine block and added a thumb screw positive engine retention. This would allow me to use any 24mm engine including Aerotech 24mm RMS.

For the shock cord mount I attached the shock cord directly to the engine mount. I drilled a hole in the forward centering ring and looped the shock cord around the engine mount and epoxied in in place. This would provide a more robust attachment for larger engines I planned on using.

I later had to add ACME aluminum rail launch lugs to the rocket. This racket is so tall and light that it will blow over a 3/16" launch rod. I had to add rail launch lugs so I could move to the big boys pad.

Another later upgrade was a "PML" style piston ejection system. I ordered a BT-60 coupler and bulkhead and threaded the shock cord thought the bulkhead with a knot on both sides.

Finishing:
This kit does not come with decals or paining guide. Following the 76er theme I painted the rocket red, white and blue like the drawing. I never did understand how they got 76er our of a 79 inch rocket but it sounds cool.

I didn't bother to fill the spirals and went strait to 2 coats of white primer. Then I painted the nose section red, the center white and the bottom blue. To finish I added two coats of clear coat. I was very pleased with the final finish. This is a crowd favorite at our club launches.

Construction Rating: 4 out of 5

Flight:
For its maiden voyage I tried to send it up on an Estes E9-6. The wind was blowing about 10mph and it blew over the launch pad and ripped the launch lugs off.

2nd attempt re-glued the launch lugs and it was on a less windy day. Again on an Estes E9-6. The flight was textbook straight and true. No wobble or spin. The rocket kinda stalled at apogee and dropped on its tail shortly before deployment. Total height was about 800ft. I don't think an D12 will get this big bird to a safe height for recovery.

I have a total of four flights on this rocket using Estes E9's. A 4 second delay seems about right. It does well in a variety of conditions. With the small fins it doesn't seem to weather cock.

For the fifth flight I thought I would try something totally stupid. I sent it up on a Aerotech F23-7. Half the people thought it would fold up coming off the pad. I had upgraded to a rail launch system with ACME rail lugs from Giant Leap. The rail was 6 foot tall to allow the rocket to come up to speed before it left the pad.

The rocket came off the pad with with authority. It flew straight and true and did not weather cock into the 12 mph breeze. The ejection went off at the 1500 ft apogee. The ejection charge was too much for the shock cord and it separated in half and the chute didn't deploy. The two halves fell to earth in a flat free fall. Both sections were recovered undamaged. The through the wall fins held up fine and the nose cone only had a slight ding in the balsa. I plan to upgrade to a Kevlar® shock cord and try this again. The rocket can handle the trust and is a very stable design.

Recovery:
Recovery is adequate for Estes E9's. If you are going to try anything larger you'll want to upgrade.

I give this design a 4 1/2 mainly based on the great stability of the design. This design is extremely stable in a variety of flight conditions and engine sizes.

Flight Rating: 4 out of 5

Summary:
Pro's:

This is a lot of rocket for the money. At 79 inches this is still the tallest rocket in my fleet. It is a real crowd pleaser. The kid love to see this big rocket leave the pad. The design is very stable and flies well under a variety of conditions.

Con's:

Manufacurer's D12 recommendation is way too small an engine to safely fly this rocket. RockSim predicts only 375 ft. An E9 is the smallest engine I would recommend. The stock construction is adequate for E9 but will need to be upgraded for anything larger.

Overall Rating: 4 out of 5

Other:
Overall I give this kit a 4 out of 5 for a low cost rocket. It has the size and potential of kits costing 3X more. This was my first through the wall and piston ejection project.

Other Reviews
  • Cygnus Rocketry - 76er {Kit} By Claude Maina (June 19, 2009)

    Brief: This is a very tall 4FNC rocket that is very similar to the Estes Mean Machine and Sunward's CFX-Six Footer. There is no skill level associated with the 76er, but since both the Mean Machine and CFX-Six Footer are considered Skill Level 2, I'll rate this the same. It is easy to build and flies well. The attraction, especially for kids, is its size. The recommended engines are ...

Flights

Comments:

avatar
M.A.G. (February 3, 2009)
This rocket is fine on a D12. Obviously an Estes D lifts more weight than an Estes E. A D12-5 leaves PLENTY of time for deployment.

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