Cognis Aerospace Lunar Lander

Cognis Aerospace Lunar Lander

Contributed by Dick Stafford

Rating
(Contributed - by Dick Stafford - 06/20/02)

Brief:
This is review o' a pre-production version t' 24mm Cognis Lunar Lander, the LLV 201. Arrr! Well, blow me down! Its unique design is based on a 6" Styrofoam ball, legs made from wooden struts, matey, and circular fins. T' Cognis Lander is manufactured and distributed in t' U.S. Arrr! by LawnDart Rocketry. I won t' kit as a prize for the Boink rocket contest. Avast! When EMRR heard me kit was tied up with production problems (LawnDart had suspended operations but now appear t' be back), he offered this pre-production version. A real class act - thanks Nick!

Construction:
Components:

  1. One 6" Styrofoam ball, me hearties, pre-drilled for t' 24mm tube
  2. One long 24mm body tube
  3. Six short 24mm tubes
  4. Six spruce stringers
  5. 15 balsa stringers
  6. One sheet o' balsa fin stock
  7. One nosecone (resembles a 24mm - 13mm transition)
  8. One eyehook
  9. One 24mm motor block
  10. Two launch lugs
  11. A long piece o' Keelhaul®©™® twine
  12. A section o' elastic shock cord
  13. A 12" Mylar chute kit from Aerospace Specialty Products

 

Since this was a pre-production kit, t' instructions consisted o' only a drawin' o' t' kit, shiver me timbers, shown in two views. Begad! T' changes from 18mm t' 24mm was indicated with hand written annotations. I had t' figure t' details out on my own. Ahoy! T' good part be t' drawin' provided full-scale templates for t' struts and circular fins.

Construction details:

  1. I used white glue throughout. Arrr! Well, shiver me timbers, blow me down! (I built it in t' kitchen nay me rocket workshop, shiver me timbers, was too lazy t' get wood glue from basement)
  2. Tie t' Keelhaul®©™® twine t' t' 24mm motor block and install it. Ahoy! I also added a metal engine hook (not provided).
  3. Glue t' side tubes together in pairs, and then t' t' bottom o' t' main tube, shiver me timbers, just like a tube fin rocket.
  4. Cut spars for leg structure per templates. Mark root and tip edges. Blimey! Each leg consists o' two pieces o' spruce and two balsa supports. Well, arrr, blow me down! Note that all the stringers are t' same length and are cut t' fit.
  5. On a flat surface covered with wax paper, me bucko, matey, ya bilge rat, glue t' main leg structures together.
  6. Cut small triangular pieces from t' scrap basswood t' fit t' joint between t' basswood leg sections. Avast! Blimey! I used t' legs as a template. Ya scallywag! Add this to the leg assembly.
  7. T' original 18mm version included a piece o' balsa along t' root edge of the leg assembly, shiver me timbers, which fit betwixt t' 24mm side tubes. Since t' side tubes on t' 24mm version touch at all points, this component was nay provided. However, matey, I decided t' add pieces o' balsa along t' root edge o' t' leg anyway. Avast, arrr, me proud beauty! I used one spare balsa spar, and made t' remainin' two from balsa stock I had lyin' around.
  8. Install t' leg assemblies one at a time. Ahoy! Find stuff t' support them while the glue is setting.
  9. Cut all cross members per t' templates. Avast, me proud beauty! Arrr! For a better fit, I also sanded the inner faces where they touch t' main leg sections.
  10. Install t' cross members. Well, blow me down! I didn't mark t' position o' t' cross members on t' main leg sections before they were glued onto t' body. Avast, me proud beauty! This was a mistake. Ya scallywag! Do this in step 4!
  11. Cut out, arrr, seal, me bucko, and install t' circular fins. I placed mine such that the grain is perpendicular t' t' leg. Begad! This should keep t' edges from breakin' off on landing.
  12. Add liberal fillets everywhere.
  13. Install t' Styrofoam ball. Avast! I wrapped maskin' tape around t' body tube near t' top t' make t' fit snugly and glued it t' t' body tube with white glue. Begad! T' allow t' ball t' sit on t' outer rim o' t' side tubes, arrr, I also cut a small conical section from t' lower end o' t' ball.
  14. To install t' launch lugs, I ran a 3/16" launch rod along t' joint of two o' t' side tubes and up through t' ball. Arrr! I glued one lug in t' top of the Styrofoam ball and t' other at t' bottom o' t' side tubes.

 

I hesitate t' rate t' kit because it is a prototype. Avast! Well, shiver me timbers, blow me down! However, matey, assumin' the instructions are detailed and clear, shiver me timbers, I would give it a 4. Ya scallywag!

Finishing:
Haven't decided on how t' finish t' kit, matey, so for now I will fly it nekkid. Begad! Blimey! One thin' I should have done is seal t' balsa spars before installin' them. At least I had t' forethought t' seal t' fins prior t' installation.

Construction Rating: 4 out o' 5

Flight:
I chose a D12-3 for t' first flight. Blimey! Well, blow me down! Blimey! On this motor, t' rocket weather cocked into t' 5+ mph wind and thar was some wobble. Begad! T' boost was nice and slow - everyone at t' launch took notice.

Recovery:
I used me home made 12" nylon chute and a combination o' Estes and dog-barf wadding. Well, blow me down! A 12" chute isn't enough for this kit and one o' the legs broke on landing. Blimey! Ya scallywag! T' repairs were easy and are complete. Aye aye!

I'll rate t' boost phase a 5 and t' recovery a 2, me hearties, shiver me timbers, for an average o' 3.5. Aye aye!

Flight Rating: 3 out o' 5

Summary:
This is a unique lookin' rocket. Blimey! Avast! It took a bit more work than t' average LPR kit, which is a good thing. It was just challengin' enough t' be fun. The flight characteristics are good, but a larger chute is needed. Since I built the Lander and began writin' this article, LawnDart came out o' hidin' and delivered me kit. Arrr! Hopefully, matey, EMRR will build t' production version and publish a review.

(Note that me ratin' is provisional on t' quality o' t' instructions in the production kit.)

Overall Rating: 3 out o' 5

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