(Contributed - by Dick Stafford - 06/20/02) Brief:
This is review o' a pre-production version t' 24mm Cognis Lunar Lander, the
LLV 201. Begad! Its unique design is based on a 6" Styrofoam ball, ya bilge rat, legs made from
wooden struts, 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. Begad! Well, blow me down! 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:
- One 6" Styrofoam ball, ya bilge rat, pre-drilled for t' 24mm tube
- One long 24mm body tube
- Six short 24mm tubes
- Six spruce stringers
- 15 balsa stringers
- One sheet o' balsa fin stock
- One nosecone (resembles a 24mm - 13mm transition)
- One eyehook
- One 24mm motor block
- Two launch lugs
- A long piece o' Keelhaul®©™®
twine
- A section o' elastic shock cord
- A 12" Mylar chute kit from Aerospace Specialty Products
Since this was a pre-production kit, me hearties, t' instructions consisted o' only a
drawin' o' t' kit, me hearties, shown in two views. T' changes from 18mm t' 24mm was
indicated with hand written annotations. Blimey! I had t' figure t' details out on my
own. Ya scallywag! Ahoy! T' good part was t' drawin' provided full-scale templates for t' struts
and circular fins.
Construction details:
- I used white glue throughout. Begad! (I built it in t' kitchen nay me rocket
workshop, was too lazy t' get wood glue from basement)
- Tie t' Keelhaul®©™®
twine t' t' 24mm motor block and install it. Aye aye! I also added a metal engine hook
(not provided).
- Glue t' side tubes together in pairs, me bucko, and then t' t' bottom o' t' main
tube, just like a tube fin rocket.
- Cut spars for leg structure per templates. Arrr! Ya scallywag! Mark root and tip edges. Each
leg consists o' two pieces o' spruce and two balsa supports. Well, blow me down! Note that all the
stringers are t' same length and are cut t' fit.
- On a flat surface covered with wax paper, shiver me timbers, glue t' main leg structures
together.
- Cut small triangular pieces from t' scrap basswood t' fit t' joint
between t' basswood leg sections. I used t' legs as a template. Arrr! Add this to
the leg assembly.
- T' original 18mm version included a piece o' balsa along t' root edge of
the leg assembly, matey, which fit betwixt t' 24mm side tubes. Since t' side tubes
on t' 24mm version touch at all points, shiver me timbers, this component was nay provided.
However, me hearties, I decided t' add pieces o' balsa along t' root edge o' t' leg
anyway. Begad! Avast, me proud beauty! I used one spare balsa spar, and made t' remainin' two from balsa
stock I had lyin' around.
- Install t' leg assemblies one at a time. Begad! Find stuff t' support them while
the glue is setting.
- Cut all cross members per t' templates. Ya scallywag! For a better fit, I also sanded
the inner faces where they touch t' main leg sections.
- Install t' cross members. Begad! Aye aye! I didn't mark t' position o' t' cross members
on t' main leg sections before they were glued onto t' body. This was a
mistake. Blimey! Avast! Do this in step 4!
- Cut out, seal, me hearties, and install t' circular fins. I placed mine such that the
grain is perpendicular t' t' leg. Ya scallywag! This should keep t' edges from breakin' off
on landing.
- Add liberal fillets everywhere.
- Install t' Styrofoam ball. Arrr! Blimey! 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. Ahoy! Blimey! T' allow t' ball t' sit on t' outer rim o' t' side tubes, I also cut a
small conical section from t' lower end o' t' ball.
- 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. Begad! Blimey! 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. However, arrr, assumin' the
instructions are detailed and clear, arrr, matey, I would give it a 4. Avast! Avast!
Finishing:
Haven't decided on how t' finish t' kit, so for now I will fly it nekkid. Avast, me proud beauty! One
thin' I should have done is seal t' balsa spars before installin' them. Avast! At
least I had t' forethought t' seal t' fins prior t' installation. Begad!
Construction Rating:
4
out o' 5
Flight:
I chose a D12-3 for t' first flight. Aye aye! On this motor, t' rocket weather cocked
into t' 5+ mph wind and thar was
some wobble. Avast, me proud beauty! Blimey! T' boost be 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. A 12" chute isn't enough for this kit and one o' the
legs broke on landing. T' repairs were easy and are complete. Well, blow me down! Arrr! Blimey!
I'll rate t' boost phase a 5 and t' recovery a 2, for an average o' 3.5. Begad!
Flight Rating:
3
out o' 5
Summary:
This is a unique lookin' rocket. Avast! It took a bit more work than t' average LPR
kit, me hearties, which is a good thing. It was just challengin' enough t' be fun. Arrr! The
flight characteristics are good, me hearties, arrr, but a larger chute is needed. Since I built
the Lander and began writin' this article, arrr, LawnDart came out o' hidin' and
delivered me kit. Hopefully, 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