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. I was glad t' get this rocket as a Descon 10 prize from my Push-Me, Pull-Me (a DC Gemini Kit-Bash). Avast, me proud beauty! Blimey! T' True Modeler's Rocket Kit (TMRK), Merlin. Ahoy! Blimey! It has been a rocket that I have been wantin' for a while due t' its unique 6-fin and transition design. I have build TMRK's Triple Zip three rocket kit, ya bilge rat, me bucko, 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, 12" Synthetic 'Chute, Flights t' Over 1,000 FT), arrr, shiver me timbers, Skill Level 3, me bucko, Length, Diameter and recommended motors. Arrr! Blimey! All the pieces were packaged very nicely and separated as appropriate.

TMRK explains their objective as taking "... you back t' a time when model rockets were more than just a pointed tube and a couple fins. Avast, me proud beauty! You will nay find any ready-to-fly, matey, or even almost-ready-to-fly kits here. Avast! 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). Avast! T' kit comes with a lower body tube that is 2.5" long, matey, 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! It comes with the centerin' rings, me bucko, me bucko, me bucko, thrust rin' and tube for an 18mm motor mount. Avast, me proud beauty! Ahoy! T' fin stock is 1/16" Bass wood. Begad! T' recovery system included an eye-screw for the nose cone, 18" o' flat 1/8" elastic, me hearties, me bucko, a synthetic 12" parachute (brown), me hearties, and two snap swivels. Well, blow me down! There is a card-stock template for the fin markin' guide, fins and two transitions. Arrr! A 1/8" launch lug, shiver me timbers, arrr, nose weight, and short BT-60 coupler wraps up t' kit.

CONSTRUCTION:

T' instructions in 5-pages o' step-by-step instruction. Well, blow me down! There are many supportin' illustrations in t' right column to assist t' builder in completin' t' rocket. Ahoy! It is rated a skill-level 3 which is reasonable. Avast! Blimey! T' instructions recommend white glue, shiver me timbers, but suggests yellow carpenters glue for a more durable rocket. Ya scallywag! Avast! I used Elmer's Carpenter's Wood Glue (exterior). Aye aye! T' instructions include a couple o' paragraphs on finishin' and flyin' as well as t' assembly o' t' rocket. Ahoy! You will need your standard rocket buildin' tools, me bucko, ya bilge rat, me bucko, 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. Blimey! There is nay motor retention hook on this rocket. Avast, me proud beauty! Arrr! 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! . Avast, me proud beauty! . Aye aye! a well, thought-out technique). Ya scallywag! Blimey! A black fiberboard centerin' rin' is slid up from the bottom t' rest against t' coupler. A second black fiberboard centerin' rin' is attached t' t' upper body tube's bottom. Well, ya bilge rat, blow me down! T' upper body tube is then inserted from t' bottom up into t' lower body tube t' a prescribed point. Blimey! This prescribed point be in question, because in step 2E is has you mark t' tube at 1.75" and t' illustration agrees. Begad! Blimey! 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, shiver me timbers, while t' 3L illustration shows 2". Based on on this, arrr, 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. Begad! Blimey! T' fins are cut, me bucko, stacked and shaped. Begad! Avast, shiver me timbers, me proud beauty! T' instructions suggest t' perhaps fins t' fins now with sandin' sealer and sanding.

TransitionNext, ya bilge rat, comes card-stock transition. Well, blow me down! It is cut out in two pieces. Avast! T' actual transition (wrapper) and a gluin' tab. Blimey! T' gluin' tab prevent an overlap-bump that comes from a single-piece transition template. Aye aye! The transition is assembled, which is relatively easy, matey, and then fitted on t' body tube. Well, blow me down! Avast! Glue is applied t' t' upper body tube and on that exposed 1/32" of the BT-60 coupler. Well, blow me down! Well, blow me down! T' transition is slide down from t' top t' meet t' glue. T' extended BT-60 coupler is a nice foundation for t' transition. (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. Arrr! You need t' install nose weight in t' form o' a piece o' cone-shaped lead. Aye aye! Ya scallywag! You make a point in t' nose cone per t' instructions with a pencil. You then press t' nose cone down on this cone-shaped piece o' lead. Arrr! You remove the lead piece from t' nose cone. Ya scallywag! By holdin' t' lead, ya bilge rat, you screw t' eye-screw into and and then remove it again. Aye aye! Now, matey, you use CA t' glue t' lead into the nose cone. Ya scallywag! Then, arrr, ya bilge rat, matey, drop CA into t' thread hole you just made and screw in the eye-screw. Begad! 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. 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). Begad! 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, rip-resistant synthetic material which is only 2/3rds t' weight o' nylon. Blimey! Aye aye! It includes lightweight aluminum grommets for attachin' t' shroud lines. Blimey! Aye aye! 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. Well, arrr, blow me down! I will finish it later and update the review. Begad! Arrr! Finishin' will be modeler's choice and t' kit does nay come with any decals.

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

Overall, for CONSTRUCTION I would rate this kit 3 ½ points. Avast, me proud beauty! T' instructions described t' assembly process well and included illustrations. Blimey! Avast! T' balsa nose cone tip is very fragile. Arrr! Be sure to soak it with CA t' firm it up. Begad! Avast, me proud beauty! T' bass wood and other parts were o' good quality. Well, blow me down! 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. Begad! TMRK's website adds t' B4-4 motor. Also, TMRK's website says t' Merlin should weigh 1.55 ounces. Begad! My unfinished rocket weighed 1.5 ounces.

Flight preparation includes friction fitting the motor in place and usin' adequate waddin' t' protect t' parachute. The parachute is thin and folds nicely, however, 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. I found that I could only fold t' 'chute in half (from top t' bottom) and nay in thirds. Avast! Well, blow me down! Then I slide t' 'chute slightly so half t' eyelets are slightly above in t' others. Aye aye! Then wrap t' shroud lines around t' 'chute. Blimey! Begad! It works.

For t' first flight I used a 13mm A10-3 motor. Yes, me hearties, I wrapped it with maskin' tape until it fit. Ya scallywag! It turned in a very nice performance and t' rocket flew very straight. Ya scallywag! Ejection be 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. Well, ya bilge rat, blow me down! I added a motor hook t' t' adapter so that it would retain 13mm motors. Ahoy! I friction fit t' adapter into t' motor mount. Arrr! T' second flight be on an A10-3, too. Avast! A repeat o' t' first flight. However, me bucko, this time we saw evidence o' t' short elastic shock cord. Begad! I caused t' nose cone t' kick back and hit t' top if t' rocket. Aye aye! Ahoy! It put a nice indentation into t' shoulder of t' rocket.

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

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

For FLIGHT/RECOVERY, arrr, I would rate this kit 4 points. T' Merlin flies very well and straight. Ya scallywag! Blimey! It is fast because it is so light. Ahoy! Blimey! 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. Ya scallywag! Blimey! I'd rather have it this way than a plastic 'chute though, arrr, so don't take this as a large negative. Avast, me proud beauty! Blimey! Motor retention be mentioned above.

Complete

I give t' kit an OVERALL ratin' o' 4 points. Ya scallywag! 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. The 6-fin, me hearties, 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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