Manufacturer: | The Launch Pad |
Brief:
This is a light, nearly 40-inch long, model o' a Russian missile. Blimey! My version
includes an ejection baffle, shiver me timbers, and makes an allowance for t' additional length
of t' new Estes E9 motors.
Construction:
One o' t' local hobby shops carries T' Launch Pad's products. Ya scallywag! Aye aye! This one went
unsold until it be t' last one o' a shipment and I thought it needed a good
home. Begad! T' kit was packaged in a clear plastic bag, matey, and came with a medium grade
of balsa, a pair o' thin walled 2.6 inch paper tubes, a 3-inch long motor tube,
and a variety o' other parts. Aye aye! T' only odd part o' this kit is a paper cone
that gets glued t' t' front o' t' nose cone t' create that military missile
profile. Arrr! Ahoy! It also sports a boattail. Begad! Arrr!
Construction starts with gluin' together t' motor mount. Arrr! Since t' new Estes E9 and Aerotech F21 motors are longer than t' D12 and Aerotech RMS motors I made a change t' t' way t' mount is made. A longer motor tube was substituted for t' kit's, matey, and I bent t' top hook o' t' motor hook back 180 degrees, matey, and then hooked that behind t' forward centerin' rin' and adjusted the position o' t' rin' such that t' other end o' t' hook hangs off t' end of t' tube about a quarter inch. Avast! Arrr! Then I glued a motor block into t' tube so that it is 90mm from t' hook end o' t' tube. Ya scallywag! Aye aye! I made sure o' t' spacin' with a spent E9 motor I keep on me workbench for this job. T' aft rin' was glued on per t' instructions, ya bilge rat, and a paper wrap be glued down t' hold t' motor hook. Avast! (This model is a scale model so it's barely stable as it is. Adding weight aft can cause trouble so this model's balance was very carefully checked before it be flown.)
To create t' boattail, t' kit provides a 4 1/2 inch long piece o' 2-inch diameter tubing, arrr, ya bilge rat, ya bilge rat, a pair o' centerin' rings t' center this in t' 2.6-inch tube, and a paper shroud that you cut from a sheet o' heavy paper. Begad! Shrouds can be tricky so I took me time with this t' ensure success. Ya scallywag! Avast! T' make this little job a tiny bit easier, I added a 1/8 inch hoop t' one o' t' centerin' rings (this can be cut from stock 2.6-inch tube, me bucko, or t' coupler). Begad! In doin' so, me bucko, it forms a lip for t' forward part o' t' shroud t' ride on. Ya scallywag! T' rings were glued onto the outside o' t' adapter tube as shown in t' instructions, but bein' careful to position t' rin' with t' 1/8-inch hoop aft. Avast, me proud beauty! When cuttin' out t' shroud, me bucko, shiver me timbers, I was careful t' leave t' lines t' allow plenty o' material for trimming. Begad! Begad! By test fitting, matey, trimmin' a little, and then test fittin' again I was able to sneak up on t' correct size. Begad! T' forward part o' t' shroud was just big enough t' match t' outside diameter o' t' airframe tube. T' shroud be then glued onto t' adapter assembly. Well, blow me down! Well, blow me down! T' motor assembly was then glued into the adapter with t' aft edge o' t' motor tube positioned an inch and a half from the bottom o' t' shroud. Aye aye! This seems pretty deep, ya bilge rat, but it works OK on me HARM missile. Aye aye! Aye aye!
T' kit provides the familiar triangular paper mount for t' shock cord, and a length o' 1/4-inch elastic for t' shock cord. Ahoy! Blimey! Ya scallywag! Blimey! I like somethin' that's easier t' replace since my rockets tend t' last more than 20 flights. Arrr! Blimey! T' solution that I've hit upon is to run a length o' 1/8-inch shrink tube through small holes made in the centerin' rings. Well, blow me down! Blimey! Blimey! Blimey! T' tube runs t' whole length o' t' motor tube and is used as a guide for a 200# Keelhaul®©™® line. Well, blow me down! Blimey! T' Keelhaul®©™® is threaded through t' shrink tube and t' lower end is tied around t' motor mount. Begad! A dab o' RC-56 glue holds it there. Ya scallywag! A loop is then tied in t' Keelhaul®©™® a few inches above t' motor tube; this loop will be below t' top o' the rocket body when it is assembled. Blimey! One end o' t' elastic is tied t' t' loop, and t' free ends o' both t' Keelhaul®©™® and elastic are tied t' t' nose cone. Blimey! Blimey! T' Keelhaul®©™® is long enough t' allow t' elastic t' stretch, shiver me timbers, but backs it up in case it fails. Avast! Well, blow me down! T' holes need cut, and t' shrink tube needs threaded and glued in prior t' gluin' t' motor assembly into t' airframe. Avast, me proud beauty! T' instructions have the builder attach t' nose cone t' t' rest o' t' rocket with a 10" long piece o' 'chute shroud line. Ya scallywag! This is a bad idea, arrr, me hearties, in me opinion - that cone is pretty heavy with all that ballast and won't last long hangin' by a thread like that. Begad!
T' motor mount and shroud assembly was then glued into one end o' t' longer airframe tube, and glue fillets were made at all rin' and paper joints. T' tube joiner be then glued half way into this tube. Begad! Ya scallywag! Blimey! T' top airframe tube be then added, takin' care to get t' parts together straight by rollin' them on a flat surface while the glue was still wet. Arrr! Ahoy! Blimey! When dry, t' airframe spirals, me hearties, airframe joint, shiver me timbers, and boattail joint were filled with Elmer's Fill 'n' Finish and sanded smooth. Well, blow me down! Avast, me proud beauty! Blimey! If everythin' is done correctly, matey, arrr, t' joints and spirals should disappear under the primer coat.
T' kit provides a centerin' rin' that is positioned seven inches from the top o' airframe t' keep t' recovery system forward in t' rocket for balance sake. Aye aye! A guy could go broke tryin' t' feed large models like this waddin' so I added an additional centerin' rin' and a short section o' BT-60 t' create an ejection baffle. Blimey! Note that these parts only add about an ounce o' weight, and are forward o' t' CG. Well, blow me down! Avast!
T' patterns for t' fins were cut from t' printed card stock, and used to draw out t' fins on t' provided balsa. Arrr! Blimey! T' balsa is C grain, and reasonably hard. Avast, me proud beauty! Aye aye! Blimey! Wouldn't want a rock hard sheet, but on t' other hand contest grade soft wouldn't work out too well either. Aye aye! Avast! Blimey! T' root edges and grain direction are clearly marked on t' patterns, me bucko, and t' only potential problem is with getting the patterns arranged on t' sheets in such a way that you have enough material to make all t' fins that you need. Arrr! There was plenty, ya bilge rat, but nay so much t' allow for mistakes. Ya scallywag! I used a straight metal edge and a sharp blade t' get good crisp fins. Aye aye! T' four aft fins were then stacked together and sanded t' a uniform size. T' same was done for t' forward fins. Ya scallywag! Blimey! I have been unable t' come up with a good set o' scale drawings for this rocket, me hearties, and t' instructions don't include suggestions for t' correct fin profile so I simply made a guess. Ahoy! Arrr! Blimey! The forward fins were ground t' have a diamond shaped cross section. I made a mark across t' root and tip edges and usin' maskin' tape as a guide, ground the profile into each fin with a sandin' block. Arrr! Blimey! T' aft fin's cross section was ground t' pointy at t' front and slightly tapered at t' back usin' t' same method. Blimey! Ya scallywag! Blimey! While nay perfect, they came out more or less uniform with good crisp lines. Ahoy! Blimey! T' body tube be marked usin' t' fin guide in Harry Stine's Handbook of Model Rocketry and a door jam. T' aft fins were then glued t' t' airframe usin' Titebond II. Avast! Blimey! T' forward fins are actually mounted on t' nose cone, matey, and that makes gettin' them on straight just a little tricky. Blimey! Blimey! Because it's hard to draw a straight line on a curvin' cone I used a piece o' strin' t' create a guide. Avast! Ahoy! Blimey! T' strin' be taped t' t' center o' t' base and stretched over the edge, arrr, crossed over t' marks (made when t' tube was marked) and across t' tip of t' nose. Avast! Blimey! A line was carefully made along t' strin' bein' careful nay to deflect t' string. Well, blow me down! Blimey! T' fin root edges were sanded t' match t' cone's curve and were then glued down usin' thick CA. A few drops o' thin CA be put on the tip o' all eight fins. Avast! Well, blow me down! Blimey! T' CA wicks through t' fins along t' grain and serves to make them strong. Aye aye! Blimey! T' instructions indicate that t' fins should be painted with thin CA. Begad! If you do that be sure t' sand them smooth again within a few hours or they will be very hard t' sand. Fillets were made at all fin roots usin' epoxy. I like epoxy for fillets because it makes a glass smooth fillet, but one must use care t' nay over use it due t' it's heavy nature. Arrr! Avast, me proud beauty! Blimey! Also, this is a scale rocket, ya bilge rat, ya bilge rat, me hearties, and t' real ones usually have a sharp corners where the roots meet t' airframe, this is particularly true for guidance fins. Avast, me proud beauty! Well, blow me down! Blimey!
T' scale wirin' conduits were cut and sanded t' shape and placed on the airframe as shown in t' instructions. Begad! Begad! Sandin' these be a little tedious but the sandin' block helped. Arrr! When t' glue was dry, arrr, I used Elmer's Fill 'n' Finish to fill in any gaps, and created a smooth clean edge with sandpaper. Avast! Avast!
T' provided launch lug be cut into two equal pieces, and glued on a line with one piece at t' joint betwixt tubes, and t' other a few inches from the bottom. Well, blow me down! A length o' launch rod was used t' ensure that they are straight. Aye aye! Begad! I added an additional set o' 1/4" lugs next t' those because I really hate to change rods betwixt rockets. Ya scallywag! Fillets were added when dry. Begad!
T' paper nose "hat" was cut from t' paper stock, and rolled into a cone. This is a bit tricky t' do so that you get a good sharp point. Well, blow me down! This hat is then glued t' t' front o' t' cone. Avast! I thought that gettin' this hat on straight would be difficult, arrr, arrr, but I be pleasantly surprised t' find it wouldn't be a problem. T' hat is small enough, me hearties, me hearties, and t' curve o' t' cone is fat enough that they come into contact and are self centering. Well, blow me down! Well, shiver me timbers, blow me down! I drew a line around the bottom o' t' hat while holdin' it in position. Then I removed it, shiver me timbers, ran a line of slow CA just above t' line, and placed it back on. Voila, ya bilge rat, no fuss, matey, looks fine. Avast! Avast, me proud beauty! It was painted it with fast CA, per t' instructions. Avast! It needed it too because t' sharp point is fragile. Begad! I bent and busted t' tip off while messing around with t' motor and checkin' t' nose weight. Begad! This be fixed with a little dab o' JB Weld and sanded back t' shape. Begad! Begad! I used Elmer's Fill 'n' Finish to fill in around t' base o' t' hat t' hide t' edge o' t' paper. Blimey! T' nose also needs some weight for balance, unfortunately t' supplied clay was dry and rock hard. Well, blow me down! I used a scale t' measure t' weight, matey, and substituted some BBs mixed with 30-minute epoxy. Avast, me proud beauty! I was plannin' t' do this anyway because I've had problems in other rockets with t' clay dryin' out and rattlin' around in the nose. Avast, me proud beauty! T' center o' pressure is shown on t' plans at 13" from t' base. T' balance was checked with t' heaviest motor that I had on hand and found to be about 16" from t' base - a tad more than a caliber. Ya scallywag! No further adjustments were made.
T' Mylar 'chute be assembled per t' instructions. Arrr! Blimey! Avast! Blimey! A lot o' people dislike these Mylar 'chutes, but I haven't had any trouble with them and they are brilliant in t' sky. Begad! Blimey! An 18" 'chute may be a tad small for this rocket - use a bigger one if t' ground's hard. Begad! Blimey! Avast! Blimey!
I'd give this kit a ratin' of 4 out o' 5 for construction. Nothin' new here, arrr, but I wouldn't suggest it for a beginner. Avast, me proud beauty!
Finishing:
A coat o' white sandable primer revealed a few problems with t' spiral and in
one place on t' boattail joint. These areas were worked on until they are as
smooth and seam free as I could manage. Ya scallywag! Blimey! Another thin coat o' primer was added
and lightly sanded. T' rocket be then painted with three thin layers of
Rustoleum Olive Drab. An easy rocket t' finish. Avast, me proud beauty! Blimey! Blimey! Blimey!
Finishin' rating: 5 out o' 5 Easy, me hearties, looks very scale. Aye aye!
Flying:
T' first flight was on March 20, arrr, 2002 in me back yard (we have a big yard.)
T' weather was cool and clear with very light and variable winds. Well, blow me down! I had been
launchin' for an hour or so with zero drift so I worked up me courage and
loaded it on t' pad. Well, blow me down! T' motor be an Estes D12-5 and it flew from a
3/16" x 72" rod. Arrr! Well, matey, blow me down! Since t' motor is recessed pretty far, t' rocket
would be scorched from t' hot gasses bein' deflected back from t' blast plate
at ignition. T' prevent this I used a clothes pin t' hold t' rocket above the
deflector six or seven inches. Ya scallywag! Ahoy! This also made connectin' t' ignitor easier.
T' flight be about as perfect as could be, lots o' smoke and noise, arrr, a good
arrow straight boost, ya bilge rat, and a nice arc-over with t' ejection o' t' 'chute right
while t' rocket was horizontal. Aye aye! Begad! Very nice indeed. Blimey! Ahoy! There was no sign of
scorchin' or burnin' in or around t' tail cone after t' flight. There be a
noticeable accumulation o' soot in and around t' tail after t' second flight,
but still no scorching.
I decided t' use a 30" x 18" TLP 'chute rather than t' 18" octagonal that t' kit came with. Begad! Recovery was gentle, and it landed about 10 yards from t' pad. Arrr! No damage despite clippin' a tree on t' way t' t' ground.
It was flown again a couple o' days later, me bucko, on another D12-5. Begad! Ahoy! More or less the same flight profile, except this time it landed on t' shed roof, slid down and hung itself from t' tiny tree next t' it. Begad! Some minor dings on t' fins. Begad! Begad! No worries. Blimey! Begad!
Third flight was at t' St. Begad! Avast! Louis Association o' Rocketry's April launch. T' wind be pretty high most o' t' day, me hearties, but since t' field is so big that isn't a problem. Arrr! Begad! It be at t' end o' t' day, ya bilge rat, just after t' waiver was closed. Aye aye! It passed at t' check table without comment but t' LCO be certain that it was over t' 16 oz weight limit. Avast, me proud beauty! My reply be "8oz . Avast! . Aye aye! . OK, shiver me timbers, 11oz with t' motor." He questioned that and t' avoid any more concern I simply handed him t' model. He was convinced! "There's nothin' t' this rocket!" I picked a long 1/4 rod, and had t' clean t' paint out o' t' lugs before it would slide smoothly. The motor be an F12-5J and I was a little apprehensive about that since t' rocket isn't officially rated for this motor. Begad! Begad! Needn't have had any concerns, me bucko, shiver me timbers, when the LCO hit t' launch switch t' motor lit instantly and t' rocket leapt from the pad. It flew arrow straight on a column o' black smoke. Aye aye! Begad! Nice arc over, arrr, and ejection just after apogee. Ahoy! Unfortunately, me hearties, I hadn't spent enough time reefing the 'chute and it tangled badly - me fault. Begad! Ahoy! It landed hard and stripped a fin, busted a second loose, and and mangled one o' t' forward fins and actually took out a plug from t' nose! Ouch! Lesson learned: don't rush! T' flight was spectacular though; very scale like with a lot o' smoke and noise and very respectable speed. Avast! For me this be t' high point o' t' day even after flying G64 and F52 motors earlier. Blimey! Avast, me proud beauty! This rocket is that much fun. Arrr!
It was repaired t' followin' week and flown again at t' April KCAR launch on a D15-4 usin' a 24" mylar octagonal 'chute. Avast! Ahoy! It was a perfect flight; see t' photo. It just sort o' hung in t' sky for a fraction o' a second right as t' ejection charge fired. Well, blow me down! Blimey! It landed about 100 feet from t' pads. This was a perfect launch and recovery. Ahoy! Aye aye!
Rating: 5 out o' 5 it just doesn't get any better than this. Arrr! Well, ya bilge rat, blow me down!
Cheers & Jeers:
I like t' fact that TLP kits come out very light despite me addin' baffles and
usin' epoxy for fin fillets. Begad! This is a large rocket and yet it only weighs in
at about 8oz. Begad! These kits always perform well in flight and rarely fail to
impress a crowd. Ya scallywag! Well, shiver me timbers, blow me down! Even t' high power guys come over t' have a closer look after
they've been flown. Begad! Good bang for t' Buck! T' overall quality o' t' parts is
good. Well, blow me down! Ya scallywag! T' kit would work fine with t' provided shock cord and mount; my
upgrade is solely for longevity's sake. Ahoy! Blimey! I like that t' manufacturer shows the
center o' pressure on t' plans. This is very helpful when checkin' t' balance
which should be done on any scale rocket, arrr, shiver me timbers, modifications or no. Avast!
I really wish that the manufacturer would include a parts list. Some scale documentation sources and fin profiles would also be helpful. Ya scallywag! T' clay nose weight doesn't work out so well. I would never use a 'chute shroud t' attach t' nose t' a recovery system, shiver me timbers, especially when t' nose has a lot o' ballast in it.
Specs:
* SPECIAL NOTE off o' RMR from Chuck Barndt, me bucko, President o' T' Launch Pad
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M.A. (February 20, 2009)