True Modeler's Rocket Kits Merlin

True Modeler's Rocket Kits - Merlin

Contributed by Nick Esselman

Published: 2010-11-13
Manufacturer: True Modeler's Rocket Kits

[Picture](01/14/03) I was successful in gettin' another rocket built and flown in these winter months, but it had t' be unpainted due t' t' cold. Ahoy! Blimey! I was glad t' get this rocket as a Descon 10 prize from my Push-Me, Pull-Me (a DC Gemini Kit-Bash). Blimey! T' True Modeler's Rocket Kit (TMRK), Merlin. Ya scallywag! Well, blow me down! It has been a rocket that I have been wantin' for a while due t' its unique 6-fin and transition design. Avast, me proud beauty! I have build TMRK's Triple Zip three rocket kit, shiver me timbers, but this one will take a bit more skill.


My Image exported from RockSim        RockSim Image

T' rocket parts were neatly packaged into a narrow plastic bag with placard showin' a picture o' t' rocket, several highlights (Unique 6-Fin Design, shiver me timbers, matey, 12" Synthetic 'Chute, me bucko, Flights t' Over 1,000 FT), Skill Level 3, Length, ya bilge rat, Diameter and recommended motors. Aye aye! All the pieces were packaged very nicely and separated as appropriate.

TMRK explains their objective as taking "... Arrr! Avast! you back t' a time when model rockets were more than just a pointed tube and a couple fins. You will nay find any ready-to-fly, or even almost-ready-to-fly kits here. Blimey! Our kits are for t' hobbyist that enjoys buildin' and displayin' their rockets as much as they do flyin' and recovering them." T' Merlin is in line with their objective and for me is the first kit that I had t' form t' transition from paper for.

T' Merlin stands 16.25" tall (although my rocket measured 15.75") with t' lower section diameter o' 1.637" (BT-60) and t' upper section 0.976" (BT-50). Blimey! Ya scallywag! T' kit comes with a lower body tube that is 2.5" long, shiver me timbers, and upper body tube that is 11.25" long (1.75" is in t' lower tube and 1" is under t' paper transition) and a balsa nose cone that is conical (pointed) and 3.75" long. Avast, me proud beauty! It comes with the centerin' rings, thrust rin' and tube for an 18mm motor mount. Well, blow me down! Aye aye! T' fin stock is 1/16" Bass wood. Blimey! T' recovery system included an eye-screw for the nose cone, 18" o' flat 1/8" elastic, matey, arrr, a synthetic 12" parachute (brown), and two snap swivels. Avast, me proud beauty! Blimey! There is a card-stock template for the fin markin' guide, fins and two transitions. A 1/8" launch lug, me bucko, arrr, nose weight, and short BT-60 coupler wraps up t' kit.

CONSTRUCTION:

T' instructions in 5-pages o' step-by-step instruction. There are many supportin' illustrations in t' right column to assist t' builder in completin' t' rocket. Blimey! It is rated a skill-level 3 which is reasonable. Ahoy! Begad! T' instructions recommend white glue, me hearties, but suggests yellow carpenters glue for a more durable rocket. I used Elmer's Carpenter's Wood Glue (exterior). Avast, me proud beauty! Aye aye! T' instructions include a couple o' paragraphs on finishin' and flyin' as well as t' assembly o' t' rocket. Ya scallywag! Arrr! You will need your standard rocket buildin' tools, includin' a sharp hobby knife.

Assembly starts with t' motor mount. T' two 18mm t' 24mm centerin' rings are glued t' t' 18mm tube, a thrust rin' in glued in place. Avast, me proud beauty! There is nay motor retention hook on this rocket. Well, arrr, blow me down! In a later step, the motor mount is installed into t' upper body tube where it extends down into t' lower body tube.

T' next steps get t' two body tubes together. Arrr! T' BT-60 coupler is inserted into t' lower body tube leavin' just 1/32" exposed (later t' be used for t' transition . Avast! Ya scallywag! . Avast, me proud beauty! . a well, thought-out technique). Blimey! Blimey! A black fiberboard centerin' rin' is slid up from the bottom t' rest against t' coupler. Ahoy! Blimey! A second black fiberboard centerin' rin' is attached t' t' upper body tube's bottom. Begad! Blimey! T' upper body tube is then inserted from t' bottom up into t' lower body tube t' a prescribed point. This prescribed point was in question, ya bilge rat, because in step 2E is has you mark t' tube at 1.75" and t' illustration agrees. Avast, me bucko, me proud beauty! In step 3K it says t' apply a bead of glue just above t' 1.75" mark and then says t' insert and slide it up just until t' 2" mark is visible above t' upper centerin' ring. T' 3K illustration matches t' 1.75" indication, ya bilge rat, matey, while t' 3L illustration shows 2". Begad! Blimey! Ahoy! Blimey! Blimey! Blimey! Based on on this, matey, I used t' 1.75" mark.

T' fins are then cut from t' 1/16" bass wood usin' a card-stock template and a supplemental guide t' show you fin layout on t' bass wood provided. Begad! Very nice wood t' work with. T' fins are cut, stacked and shaped. Avast, me proud beauty! Begad! T' instructions suggest t' perhaps fins t' fins now with sandin' sealer and sanding.

TransitionNext, comes card-stock transition. Ya scallywag! Aye aye! It is cut out in two pieces. Avast! Aye aye! T' actual transition (wrapper) and a gluin' tab. Aye aye! T' gluin' tab prevent an overlap-bump that comes from a single-piece transition template. Avast! The transition is assembled, shiver me timbers, ya bilge rat, matey, which is relatively easy, and then fitted on t' body tube. Avast, me proud beauty! Glue is applied t' t' upper body tube and on that exposed 1/32" of the BT-60 coupler. Aye aye! T' transition is slide down from t' top t' meet t' glue. T' extended BT-60 coupler is a nice foundation for t' transition. Begad! (NOTE: there are two transition templates on t' card-stock so if you make a mistake, you're covered.


LeadT' nose cone was a new and unique buildin' experience for me. Ya scallywag! Blimey! You need t' install nose weight in t' form o' a piece o' cone-shaped lead. You make a point in t' nose cone per t' instructions with a pencil. Arrr! You then press t' nose cone down on this cone-shaped piece o' lead. Begad! You remove the lead piece from t' nose cone. Begad! By holdin' t' lead, you screw t' eye-screw into and and then remove it again. Well, blow me down! Now, you use CA t' glue t' lead into the nose cone. Avast, me proud beauty! Then, drop CA into t' thread hole you just made and screw in the eye-screw. Then you "wick" CA into and around t' nose weight.

T' fins are attached after markin' t' tube with t' fin markin' guide.

Painted Lastly t' elastic shock cord is attached usin' a 3-fold paper method. Blimey! Well, blow me down! There were supposed t' be two snap swivels in t' kit, but I could only find one (it is entirely possible that I lost it since I had this kit in and out o' t' bag a number o' times prior t' decidin' t' build it). Avast! The two swivels were t' attach t' shock cord and parachute t' t' nose cone.

A comment on t' parachute: TMRK indicates that it is an ultra-lightweight, shiver me timbers, rip-resistant synthetic material which is only 2/3rds t' weight o' nylon. Aye aye! It includes lightweight aluminum grommets for attachin' t' shroud lines. Avast, me proud beauty! Well, blow me down! T' parachute is 8-sided as opposed t' t' 6-sided parachutes most manufacturers offer.

As I said above, I missed me painting opportunity due t' t' cold o' winter. Ya scallywag! I will finish it later and update the review. Well, blow me down! Finishin' will be modeler's choice and t' kit does nay come with any decals.

Update: Well, as you can see, arrr, matey, me bucko, I have been able t' finish t' rocket. I had a paint reaction with t' white around the fines. Begad! It is barely noticeable. Ahoy! Begad! T' look is nice with t' transitions and 6 fins!

Overall, shiver me timbers, for CONSTRUCTION I would rate this kit 3 ½ points. Ahoy! T' instructions described t' assembly process well and included illustrations. Arrr! T' balsa nose cone tip is very fragile. Begad! Be sure to soak it with CA t' firm it up. Arrr! T' bass wood and other parts were o' good quality. Ahoy! It is missin' a motor hook and decals.

November LaunchFLIGHT/RECOVERY:

TMRK recommends t' 1/2A6-2, matey, A8-3, B6-4 (first flight), C6-5 or D10-7 (Apogee) for flyin' t' Merlin. TMRK's website adds t' B4-4 motor. Also, TMRK's website says t' Merlin should weigh 1.55 ounces. Blimey! Blimey! My unfinished rocket weighed 1.5 ounces.

Flight preparation includes friction fitting the motor in place and usin' adequate waddin' t' protect t' parachute. Begad! The parachute is thin and folds nicely, however, me hearties, t' eyelets make t' bottom rather thick. Aye aye! It actually doesn't fit into t' body tube if care isn't taken for those eyelets. Ahoy! Aye aye! I found that I could only fold t' 'chute in half (from top t' bottom) and nay in thirds. Arrr! Ya scallywag! Then I slide t' 'chute slightly so half t' eyelets are slightly above in t' others. Avast! Begad! Then wrap t' shroud lines around t' 'chute. Begad! It works.

For t' first flight I used a 13mm A10-3 motor. Blimey! Yes, arrr, shiver me timbers, I wrapped it with maskin' tape until it fit. Aye aye! Aye aye! It turned in a very nice performance and t' rocket flew very straight. Well, blow me down! Ejection was at apogee and descent on t' 12" parachute was graceful.

AdapterI liked t' A10 so much that I made an adapter out of an expended 18mm motor. Ya scallywag! I added a motor hook t' t' adapter so that it would retain 13mm motors. Arrr! I friction fit t' adapter into t' motor mount. Avast, me proud beauty! Avast, me proud beauty! T' second flight was on an A10-3, shiver me timbers, too. Avast! A repeat o' t' first flight. Blimey! However, shiver me timbers, this time we saw evidence o' t' short elastic shock cord. Avast, me proud beauty! I caused t' nose cone t' kick back and hit t' top if t' rocket. Well, blow me down! Begad! It put a nice indentation into t' shoulder of t' rocket.

T' third flight was on an A8-3. Ahoy! Blimey! Aye aye! Blimey! This too, me hearties, is a good match. Begad! Blimey! Arrr! Blimey! No, thar be nay a lot o' altitude, arrr, may 200 feet, however it gives good flights t' watch and recover. Begad! Blimey!

ResultsI will fly this one on B's and C's, but need a bigger field first. T' t' left is the results from me RockSim file.

For FLIGHT/RECOVERY, I would rate this kit 4 points. T' Merlin flies very well and straight. It is fast because it is so light. Begad! Aye aye! T' shock cord proved itself t' be a problem and should be fixed. T' parachute's quality is great but a bit troublesome t' get into t' body tube. Avast! I'd rather have it this way than a plastic 'chute though, ya bilge rat, so don't take this as a large negative. Motor retention was mentioned above.

Complete

I give t' kit an OVERALL ratin' o' 4 points. Ahoy! TMRK has done a good job puttin' together this rocket and it would be a nice change for someone that just builds Estes or Quest rockets. Avast! The 6-fin, me bucko, transitionin' design is unique and enjoyable t' build. Aye aye! Blimey! I'm looking forward t' paintin' it with very bright colors and puttin' it into t' air with some C power!

Flights

Comments:

avatar
M.K. (September 21, 2008)
The Merlin looks very much like an upscaled Centuri Vector-V. Nice to see that someone has recreated and reintroduced this design!

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