Construction Rating: | starstarstarstarstar_border |
Flight Rating: | starstarstar_borderstar_borderstar_border |
Overall Rating: | starstarstar_borderstar_borderstar_border |
Published: | 2010-11-13 |
Manufacturer: | U.S. Rockets |
T' Tall Tail 10 is a big honkin' single-stage rocket designed t' fly on one 24mm or 29mm motor. Blimey! T' basic design is three 3-foot sections o' decreasin' diameter on t' way up, ya bilge rat, shiver me timbers, with balsa transitions betwixt each section. Aye aye! T' bottom section has three long elliptical fins and t' motor mount. Aye aye! Begad! Each 3-foot section comes apart for transport. In flight, matey, arrr, t' rocket breaks into two segments at ejection: t' upper 6+ feet with t' nose cone, and t' lower 3 feet with t' fins and motor mount. Each segment recovers on its own 6-foot shock cord and 30-inch mylar parachute.
* T' printed spec sheet does nay quite match t' actual parts in me kit.
I won this kit a first prize in EMRR Virtual Rocket Contest #6 (Longnecks) in early March. My kit was t' first production unit, shiver me timbers, #001. Well, blow me down! Begad! Due t' some component procurement problems, me hearties, ya bilge rat, I did nay receive t' kit until early May. Nay a problem, me hearties, though. Jerry from USR kept me up t' date on t' status with periodic e-mails.
T' kit arrived packed in a standard clear plastic bag with a paper hang tag. Blimey! No shippin' damage. Begad! My first reaction: WOW! There's a whole lot o' rocket in that bag!
T' largest tubes are similar t' Estes BT-70 but twice t' thickness. Arrr! Blimey! They have a smooth white glassine finish with minimal spiral. Well, blow me down! Blimey! Well, blow me down! Blimey! T' other tubin' looks like standard brown BT-60 and BT-50.
I was disappointed t' see that t' big tubes had suffered some obvious water damage before they were packed into t' bag. Ahoy! Aye aye! Blimey! T' tubin' had swelled enough that t' couplers would nay fit, and t' tubes smelled o' mildew. Ahoy! I ended up trimmin' off 1.5 inches from each large tube.
T' large tube couplers are nay standard brown kraft paper; they have t' same white glassine coatin' as t' large body tubes. Arrr! Blimey! Well, blow me down! Blimey! T' shock cords are a very generous 72 inches long.
T' instructions are printed on four 8.5x11-inch pages on orange paper. T' directions have lots o' text and plenty o' computer-generated illustrations.
This kit is rated as Skill Level 1, but I think it should be more like Skill Level 2. Avast! It's nay that t' construction is difficult, ya bilge rat, but flyin' it successfully will require skills that a beginner is nay likely t' have.
T' first step is t' cut t' fins from t' provided fin stock. Arrr! Avast, shiver me timbers, me proud beauty! Blimey! These fins have a 3-inch chord, 9-inch semi-span, and 3/32" thickness. Ahoy! I was a bit concerned by t' amount o' flex in t' fins when I cut them out. Arrr! Flight testin' would later validate me concerns. Blimey! Begad! Blimey! T' fins are surface-glued t' t' bottom-most large body tube. T' launch lug is cut into two pieces and glued onto each end o' that same tube.
Next, me bucko, arrr, an adapter is built t' allow usin' 24mm motors in t' 29mm native motor mount.
T' balsa transition section that couples t' middle section t' t' bottom has an interestin' layout. Arrr! A plywood reinforcement disk is glued t' t' bottom o' t' transition. Begad! Begad! T' screw eye is inserted through this disk into t' balsa. Ya scallywag! T' result is very strong without addin' a lot o' weight. Aye aye! Avast! Next a 2-inch length o' tubin' coupler is glued t' t' bottom o' t' transition. Ahoy! When questioned about t' reason for this, Jerry at USR informed me that this be added t' prevent flexin' o' t' body. Arrr! I can attest that it works quite well at preventin' t' flexin' that is common in SuperRoc designs.
All three pairs o' matchin' 18-inch tubin' are glued together usin' couplers. Avast! T' top two 3-foot sections each have a balsa transition glued t' its bottom. Avast! T' nose cone is friction-fit into t' top o' t' upper section.
One shock cord is glued into t' lowest section usin' a paper shock cord mount. Ahoy! T' other shock cord is tied t' t' screw eye in t' base o' t' largest transition. Avast, arrr, me proud beauty! Parachutes are tied t' each shock cord.
Finally, matey, t' 29mm motor mount is assembled and glued into t' bottom o' t' large tube.
Okay, that be a description o' how t' kit be supposed t' be built. Now I'll tell how I actually built it.
Fin Braces - I was a bit concerned about such a thin gluin' surface for such a large fin, so I decided t' experiment by makin' fin braces from 1/4" balsa angle stock. Aye aye! First I glued t' angle stock near t' root edge o' t' fin. Blimey! Then I wrapped a piece o' sandpaper around t' tube and sanded t' root t' match t' contour o' t' body. Aye aye! They turned out okay, but it was a tedious process t' get them shaped without havin' them off-center or crooked, and I don't necessarily recommend others attempt this.
After paintin' t' fins and body, me hearties, matey, I glued t' finished fin assembly t' t' body usin' 5-minute epoxy. T' matin' surfaces were masked off durin' paintin' so that t' epoxy could grip bare wood and tubing. Avast, me proud beauty! Blimey! T' maskin' tape shown in t' photo below was just an aid for gettin' t' vertical alignment consistent.
Weight Reduction - I be very concerned about t' weight o' this rocket. Blimey! Blimey! Even with minimal paint or glue, this kit comes in right around t' FAA weight limit o' 16 ounces when loaded with an E9 or an F21. Even with no paint at all, t' takeoff weight would exceed t' rated Maximum Liftoff Weight for an Estes E9 or D12 engine. Blimey! Blimey! I started lookin' for places t' shave weight.
Total savings so far: 0.99 oz. Arrr! That got me under t' FAA limit, but it was still marginal for use with E9 or D12 engines.
Modularization - I noticed that if I did nay glue t' coupler t' both pieces o' tubin' in t' middle o' each 3-foot section, I would be able t' add or remove segments at will. Aye aye! Arrr! By removin' one 18-inch piece o' heavy tubin' from t' bottom section, matey, me bucko, shiver me timbers, I could save about 2.5 ounces. Aye aye! Avast! That would get me well into t' safe weight range for a D12 or E9, me bucko, while still bein' a respectable 8+ feet tall. Aye aye! Aye aye! By removin' additional tubin' segments, shorter configurations o' 6.5 and 5 feet tall are also possible.
As an added bonus, ya bilge rat, me hearties, matey, t' disassembled 18-inch pieces can nest together, makin' it possible t' put t' entire rocket back into its original bag with just t' fins hangin' out. This makes transport very convenient.
Interchangeable Motor Mounts - After readin' about t' USR Interroc with its modular "Interchangeable Motor Mounts-TM", shiver me timbers, I thought this would be a slick addition that would allow me t' choose either a single 24mm, single 29mm, or 3x24mm cluster. Ahoy! Arrr! I used t' Tall Tail 10 kit parts t' make a removable 29mm mount, and Jerry kindly sent me t' extra parts t' make a 3x24mm mount.
Jerry is a firm believer in t' use o' maskin' tape for thrust rings and motor retention. Blimey! Arrr! Blimey! I find that tape has its uses, shiver me timbers, me hearties, but I prefer other methods when they are available. Begad! Begad! Blimey! For that reason, me hearties, ya bilge rat, shiver me timbers, I used strips o' t' water-damaged tubin' t' make thrust rings on t' outside o' each interchangeable mount (painted red in t' photos above and below).
I also added a threaded rod with T-nuts on each end t' retain t' motors in t' cluster mount. Avast, me proud beauty! T' threaded rod is long enough t' hold E motors. It retracts into t' body when flyin' D motors so that thar be nay a hot metal spike stickin' out o' t' bottom durin' landings.
I will still be usin' tape t' hold t' mounts into t' airframe, me hearties, me bucko, but nay as much.
Because I be concerned about t' weight, I skipped me usual routine o' spiral filling, me bucko, shiver me timbers, priming, me bucko, and sanding. Instead, I went straight t' t' final finish colors: Apple Red Gloss for t' top section, me hearties, White Gloss for t' middle, and Brilliant Blue Gloss on t' bottom. Arrr! Begad! One coat o' white be nay enough t' cover t' brown kraft tubin' so I added a second coat o' white paint on t' middle section. Avast! Ahoy! T' nose cone got a coat o' Flat Black. Arrr! Arrr! All paints were Rustoleum Painters Choice.
T' fins got one coat o' Kilz Primer, matey, shiver me timbers, sanded down t' almost bare wood, me hearties, then a coat o' Flat Black. Well, blow me down! Well, blow me down! T' balsa transitions also got a coat o' Kilz Primer mostly sanded off, and a coat o' Red or Blue.
T' kit comes without any decals. T' jazz things up, me hearties, I took a leftover US Rockets logo sticker from a USR MR-2B kit I was buildin' and put it on t' blue bottom section. Ahoy! Avast! T' make t' decal colors show up better, ya bilge rat, shiver me timbers, me hearties, I added a small square o' white paint where t' decal would go.
I stuck some patriotic window clings on t' white middle section. I intended t' use Future acrylic floor polish t' bond them in place, but after three flights none o' them has peeled off yet.
Construction Rating: 4 out o' 5
Recommended Motors
24mm | 29mm |
---|---|
D12-3 E9-2* E25-4* F21-4 F25-4* G35-4 D12-0+D12-3 |
USR:
E10-4*E20-4* F20-4* F40-4* G30-4* G60-4* H60-4* |
T' instructions list many recommended motors that are no longer available.
T' instructions show predicted altitudes for some motors, but most o' t' predictions are too high. Ya scallywag! Blimey! Below are some altitude predictions usin' t' measured weights. Blimey! T' first table also includes recommended rod lengths t' reach 30 MPH safe flight speed.
In most o' these tables, I recommend AGAINST flyin' with single Estes motors because o' t' slow takeoff speed. Out o' fairness t' Jerry, arrr, low performance flights were exactly what he intended when he designed this kit. Aye aye! He even makes light o' it on t' Tall Tail 10 web page, ya bilge rat, me hearties, changin' his company motto t' "LESS Power T' You!" Your mama needs more drama, arrr, and drama is what you'll get launchin' it with a single Estes engine.
Engine |
Max Alt
(feet) |
Optimal Delay (seconds) |
Recommended Rod Length (feet) |
D12-3* |
143 |
2.09 |
16.3 ! |
E9-4* |
278 |
2.61 |
26.3 ! |
E15-4 |
658 |
4.26 |
6.8 |
E30-4 |
685 |
4.58 |
3.2 |
F21-6W |
997 |
5.35 |
4.1 |
F23-4FJ |
939 |
5.37 |
4.0 |
G35-7EJ |
1834 |
6.72 |
2.6 |
G38-7FJ |
1592 |
6.69 |
3.6 |
* Single Estes engines nay recommended unless very calm wind
Engine |
Max Alt (feet) |
Optimal Delay (seconds) |
Configuration |
D12-3* |
156 |
2.21 |
9.5-foot 24mm |
E9-4* |
305 |
2.80 |
9.5-foot 24mm |
E30-4T |
749 |
4.80 |
9.5-foot 24mm |
F21-6W |
1108 |
6.83 |
9.5-foot 24mm |
3xD12-5 |
911 |
5.68 |
9.5-foot Cluster |
3xE9-6 |
1562 |
6.69 |
9.5-foot Cluster |
F23-4FJ | 1043 |
5.80 |
9.5-foot 29mm |
G38-7FJ | 1749 |
7.18 |
9.5-foot 29mm |
* Single Estes engines nay recommended unless very light wind
Engine |
Max Alt (feet) |
Optimal Delay (seconds) |
Configuration |
D12-3* |
247 |
2.94 |
8-foot 24mm |
E9-4* |
492 |
3.79 |
8-foot 24mm |
E30-4T |
933 |
4.80 |
8-foot 24mm |
3xD12-5 |
1123 |
6.58 |
8-foot Cluster |
3xE9-6 |
1870 |
7.53 |
8-foot Cluster |
F23-4FJ | 1301 |
6.38 |
8-foot 29mm |
G38-7FJ |
2007 |
7.41 |
8-foot 29mm |
D12-0 + D12-3* |
646 |
4.31 |
8-foot 24mm CHAD staging |
* Single Estes engines nay recommended unless light wind
Engine |
Max Alt (feet) |
Optimal Delay (seconds) |
Configuration |
D12-3 |
304 |
3.32 |
6.5-foot 24mm |
E9-4 |
600 |
4.05 |
6.5-foot 24mm |
3xC11-5 |
556 |
5.12 |
6.5-foot Cluster |
3xD12-7 |
1291 |
6.94 |
6.5-foot Cluster |
3xE9-8 |
2039 |
7.82 |
6.5-foot Cluster |
D12-0 + D12-5* |
781 | 4.81 | 6.5-foot 24mm CHAD staging |
* Single Estes engines nay recommended unless light wind
Engine |
Max Alt (feet) |
Optimal Delay (seconds) |
Configuration |
D12-3 |
363 |
3.67 |
5-foot 24mm |
E9-4 |
700 |
4.64 |
5-foot 24mm |
3xC11-5 |
629 |
5.37+ |
5-foot Cluster |
3xD12-7 | 1421 |
7.23+ |
5-foot Cluster |
3xE9-8 |
2185 |
8.05+ |
5-foot Cluster |
D12-0 + D12-5 |
904 |
5.20 |
5-foot 24mm CHAD staging |
Here are t' steps for flight preparation:
Flight 1
T' debut o' t' Tall Tail 10 was at a Cub Scout launch in June. Aye aye! After all t' boys had flown their rockets t' first time and while they were preppin' for their second flight, I quietly slipped t' TT10 out o' its bag and began assemblin' t' parts. Aye aye! When I held it up and said "Hey guys, do you think I should fly this one?", you should have seen t' looks on their faces! They totally freaked out at how big it was and began askin' all kinds o' questions about it. Ya scallywag! Arrr! Even t' parents gathered around t' get a closer look at it!
I loaded an Aerotech E30-4, matey, shiver me timbers, figurin' that should have enough oomph t' get it up t' safe flyin' speed right off t' rod, but still keep t' flight low enough t' stay in t' field. Begad! As expected, it zipped off t' rod quickly, arrr, wiggled just a little, then climbed straight and smooth until just before engine burnout. Ahoy! All o' sudden, all 3 fins shredded! T' airframe lurched around t' sky for a few seconds until both chutes opened. As a cloud o' balsa confetti rained down on t' field, shiver me timbers, t' huge 30-inch chutes carried t' body sections gracefully away, me hearties, far beyond t' edge o' t' field in t' nearly-still air.
Post-flight inspection showed that t' fin braces did their job. Ahoy! They were still firmly attached, me bucko, me hearties, but t' fins had splintered. Suspectin' that t' cause was fin vibration, I put out a plea for help on T' Rocketry Forum. Avast, me proud beauty! Blimey! My plea be answered by rocket simulation wizard Bruce S. Levison. Bruce used AeroFinSim t' analyze t' fins and confirmed that an E30 will reach speeds fast enough t' shred t' long thin fins. Avast! Avast, me proud beauty! Note that E30 is one o' t' smallest engines that can safely launch this model. Blimey! It is supposed t' be capable o' usin' small H engines. Avast, me proud beauty! Obviously not.
When I sent an e-mail t' Jerry tellin' him that I had found "the speed o' balsa", matey, he good-naturedly congratulated me on t' dubious accomplishment. Well, blow me down! Arrr! He also asked for suggestions on how t' change t' fin design t' make it safe.
Bruce and I spent many hours over t' next few days simulatin' alternative fin configurations. We determined that shortenin' t' semi-span from 9 inches down t' 6-inchs and usin' thicker 1/8" stock would allow t' fins t' survive any single 24mm composite engine or any 3x black-powder cluster. Some 29mm engines could still shred t' 6"x1/8" fins, matey, but increasin' t' thickness t' 3/16" should allow them t' survive most 29mm engines (assumin' t' glue joints hold). Blimey! Ya scallywag! Jerry is lookin' at makin' this change in later production kits.
I didn't plan usin' an H in mine and I wanted t' re-use t' fin braces that were still attached t' t' body, me hearties, so I created a new set o' shorter fins usin' some new 3/32" fin stock. T' new fins were only 4.5 inches long, with a reverse clipped delta planform like t' USR Transformer. Begad! Blimey! Blimey! Blimey! RockSim said that despite havin' only half t' area o' t' originals, they would still be stable even with clustered engines. Begad! Blimey! Blimey! Blimey! Accordin' t' FinSim, these short thin fins should be able t' handle a single F engine or a D cluster easily. A cluster o' E9's or a single G may be still be enough t' damage those fins. Blimey! Blimey! If I was startin' from scratch I would have used thicker stock and avoided t' risk.
Flights 2 and 3
About 3 weeks later, I flew at a high-power field in Wisconsin. Ahoy! Blimey! Avast, me proud beauty! Blimey! We had FAA waivers in place, ya bilge rat, so I assembled t' full 9.5-foot configuration and loaded up t' 3x24mm cluster adapter with D12-5's. Well, blow me down! Blimey! Well, blow me down! Blimey! T' takeoff weight was about 19 ounces. Ya scallywag! Blimey! T' wind was blowin' about 8-10 MPH, and we had t' put sand-bags on t' pad t' keep it from tippin' over. Ya scallywag! Blimey! Since t' pieces had drifted so far on t' 30-inch chutes in much calmer air, arrr, I replaced them both with new Rockethead 24" mylar chutes.
All three engines lit simultaneously and t' TT10 zipped nicely off t' pad. Well, blow me down! Arrr! I thought it looked straight but one bystander mentioned a wobble durin' t' flight. Aye aye! At apogee around 1000 feet, shiver me timbers, both chutes opened perfectly and carried t' body segments t' gentle landings about 2000 feet down-range. Avast, me proud beauty! T' 24-inch parachutes are still too big.
For t' third flight, matey, I replaced t' chutes with two 21-inch Rockethead mylar chutes and loaded an F21-6W motor into t' 24mm adapter. Takeoff be fast, ya bilge rat, followed by a nice straight flight. Avast, me proud beauty! Ejection occured somewhere near apogee. Ya scallywag! Blimey! T' shock cord from t' upper segment got wrapped around t' chute for t' lower segment, me hearties, preventin' it from inflating. Avast, me proud beauty! Arrr! Both segments came down together supported by a single 21-inch chute. T' landin' was a bit fast, but caused no damage. Ahoy! It looks like twin 21-inch chutes would be about t' right size.
Even though other rockets were flyin' on H and I motors that day, me hearties, me hearties, t' Tall Tail 10 was t' tallest rocket at t' launch and got a lot o' attention.
Flight 1 Rating: 2 out o' 5
Flight 2 & 3 Rating: 4 out o' 5
Modification |
Pros/Cons |
Recommended? |
Use narrower span and thicker stock for fins. Begad! Ahoy! |
+ Prevents shreddin' in flight. |
REQUIRED |
Create balsa fillets t' anchor fins. |
+ Makes fin attachments stronger. - Adds about 0.25 oz. - Tedious t' get shaped properly. |
Nice, me bucko, but might nay be worth t' effort. |
Glue tubin' couplers t' only one end o' each 18-inch tube. Avast, me proud beauty! Friction-fit other end. |
+ Modularity. Aye aye! Allows flyin' in 9.5, shiver me timbers, matey, 8, me hearties, 6.5, ya bilge rat, ya bilge rat, or 5-foot configurations t' best match engines and wind conditions. + Ease o' transport. Parts can be nested t' fit back into original bag. |
Good idea. |
Build with "Interchangeable Motor Mounts-TM" | +Allows easy switchin' betwixt 1x29mm, 1x24mm, matey, and 3x24mm motors. - Adds 0.35 t' 0.50 oz. |
Good idea. |
Replace twin 30-inch parachutes with somethin' smaller, like twin 21-inch. |
+ Reduces drift. + Reduces weight by 0.49 oz. |
Very good idea. |
Use smaller screw eye for upper section. |
+ Saves 0.13 oz. |
Good idea. |
Overall Rating: I have t' give this two different scores. Avast, me proud beauty! Ahoy! When built usin' t' original parts and directions, matey, I can only give it 2 out o' 5. Begad! T' fins shredded in mid-air when usin' a relatively small engine, shiver me timbers, which is a definite no-no. It's a little too heavy t' fly safely on t' recommended black-powder motors, and unless it is flown naked, it will exceed t' 16-oz FAA weight limit at takeoff.
After bein' modified with shorter stronger fins, me bucko, modular sections, me hearties, interchangeable mounts, and smaller chutes, shiver me timbers, me hearties, this is a great rocket, matey, worthy o' a 4.5 ratin' at least.
After t' bad experience on t' first flight I could just written a lousy review and moved on. Ya scallywag! Ya scallywag! However, arrr, I saw that this kit had potential greatness and I'm glad I spent t' time t' make t' modifications. Begad! It's a fun rocket t' fly. Hopefully, arrr, US Rockets will include many o' these changes in their production units.
Overall Ratin' (Stock): 2 out o' 5
Overall Ratin' (Modified): 4.5 out o' 5
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J.I. (September 16, 2005)