Photo from Sunward that enticed me t' purchase t' Interplanetary Shuttle™

T' Sunward Interplanetary Shuttle caught me attention despite t' unfinished look o' t' advertisement. I thought t' center tube looked really interesting. Blimey! Aye aye! T' overall look was unique with t' t' fins wrappin' around t' center tube and extendin' t' entire length o' t' rocket.

T' rocket kit comes complete with t' 0.976" diameter body tube (central) and t' 2.1" diameter center tube that gives it t' unique look. Blimey! T' plastic nose cone uses clay nose weight. Avast, me proud beauty! There are four laser-cut balsa fins and two laser-cut centerin' rings that are used for t' center tube. Avast, me proud beauty! T' kit includes an 18mm motor mount with a retainin' hook. Well, blow me down! It also includes t' plastic parachute that needs t' be assembled.

Construction:

T' instructions are printed on six pages o' 8½ x 11" paper which include a Launch Prep section and both t' NARRRRR and CAR safety codes. There is a fin markin' template that needs t' be cut out from page 2 o' t' instructions. Begad! They include illustrations t' assist in t' build.

Sunward calls t' kit a Skill Level 2 and we agree. Ya scallywag! Blimey! Begad! Blimey! It is a fairly easy kit t' build, however, with t' fit o' t' center tube and t' fins around that tube, shiver me timbers, shiver me timbers, attention t' detail is required.

T' motor mount is assembled first and it seems that Sunward has standardized this portion o' t' kit.

I decided t' cover t' fins with newspaper t' help in t' finishin' process. Ya scallywag! Ya scallywag! So before gluin' them in place, I coated each side with Modge-Podge and placed a piece o' newspaper over them. Avast, me proud beauty! Then place them betwixt wax paper and under heavy books. They will warp if you do nay do both sides at once and place it on a flat surface with heavy flat surface on top.

I really want t' spend a little time on t' central tube because this is probably t' most challengin' portion o' t' build. What makes it a little more challengin' (and in me opinion unnecessarily so) is that t' top and bottom laser-cut balsa caps used for t' center tube are exactly that... Begad! caps. In other words, ya bilge rat, matey, they do nay fit inside t' center tube t' ensure that it is centered, me bucko, me hearties, arrr, they sit on t' outside and t' center tube has t' be aligned t' be even with these caps. Arrr! I believe that if they were used as centerin' rings (fit into t' center tube) t' build would be better.

T' instructions have you mark your body (central) tube at 5 5/8" then glue t' first balsa cap in place. Ya scallywag! Aye aye! Then they have you glue t' center (larger diameter) tube t' that cap, matey, me bucko, me hearties, followed by t' second cap. Ya scallywag! I be uncomfortable with this approach for three reasons: 1) I didn't know which side o' t' 5 5/8" line I should align to; 2) I didn't trust myself t' get t' first balsa cap perpendicular/even with t' central body tube, and 3) I didn't like t' "floating" center tube arrangement. Begad! Avast, me proud beauty! Next, me bucko, arrr, ya bilge rat, I'll tell you what I did, ya bilge rat, however, shiver me timbers, it should be noted that followin' t' instructions will work.

I took two o' me fins, both caps and t' center (larger diameter) tube and test fit them all together. Begad! Blimey! T' cut on t' fins are so perfect that this allowed t' assembly t' be "held" together without glue. Begad! Blimey! I then was able t' slide t' center tube and caps up and down t' align t' fins t' t' body tube. Blimey! Blimey! Begad! Blimey! T' fins are slightly longer than t' body tube. Aye aye! Blimey! Avast! Blimey! (T' placard shows that extra portion extendin' above t' body tube where t' nose cone would go. If you look closely at me finished rocket, arrr, shiver me timbers, I ensured that extra was at t' bottom o' t' rocket.)

Once I had t' assembly and fins where I wanted them, I touched t' upper cap in several places with CA. Aye aye! I then removed t' fins, me hearties, bottom cap and center tube. I then applied a nice fillet o' glue t' t' underside o' t' top cap (pictured right).

After that dried, matey, I put glue on t' top and bottom edges o' t' center tube and placed it onto t' upper cap. Blimey! I then slid t' bottom cap down onto t' center tube. I used t' two fins t' check alignment and while they were in place, matey, touched t' bottom cap in several places with CA (pictured below). Avast! I then removed t' fins and set t' assembly aside t' dry.

Once t' CA was dry, me hearties, I added a fillet o' glue t' t' outside o' t' top and bottom caps.

All t' fins fit nicely around t' central tube, however, shiver me timbers, I had t' sand t' root edges t' ensure that they set "down" onto t' central tube. Begad! This took a bit o' work t' have them fit nicely. Avast, me proud beauty! Once done, me bucko, each fin was able t' be glued into place.

Before gluin' them into place, matey, arrr, I cut out t' tube-markin' template and wrapped it around t' body tube. Ya scallywag! There were only three fin lines t' be marked. Avast, me bucko, me proud beauty! I looked at t' placard and it looked like t' rocket had three fins. Begad! I re-checked t' instructions thinkin' I did somethin' wrong. Well, blow me down! T' instructions said four fins and therefore I went ahead and marked t' tube usin' me Estes Tube-Markin' tool with four fin lines. (Sent a note t' Sunward and they were aware o' t' problem and was surprised that me kit came out with t' wrong template).

Finishin' this rocket be tough! Blimey! T' spiral-groove in t' center tube was very deep and I ultimately had t' fill it with an automotive fillin' glaze. Ahoy! Blimey! Begad! Blimey! After several coats o' Plasti-Kote. Aye aye! Blimey! I then used t' new Krylon paint I had left over from another build. Avast! Blimey! I used t' green as t' base. Well, blow me down! Blimey! T' next day I covered t' fins and attempted t' coat with Krylon red. Blimey! Blimey! Oh, it didn't work out. Blimey! Blimey! Some wrinkles and some paint stuck and pulled off with t' tape. I be out o' time and needed t' box it t' get it mailed t' Maryland for NARAM.

T' kit didn't come with decals. Ya scallywag! Interestingly, matey, this could be a really neat lookin' rocket if it was painted white with black fins. Ahoy! Then if thar were some port-hole decals on t' center tube. Ahoy! Avast, me proud beauty! You get t' idea.

Overall, for CONSTRUCTION I would rate this kit 3 points. Avast! Blimey! T' rocket is fairly easy t' build with t' only challenge bein' t' alignment o' t' center tube t' t' body (central) tube and fins. Begad! Well, me hearties, blow me down! Blimey! Had t' one little issue with t' 3-fin template when it was supposed t' be a 4-fin template. T' instructions are just okay and no decals.

FLIGHT/RECOVERY:

Sunward recommends t' followin' motors: A8-3, A8-5, matey, B4-2(first flight), B4-4, B6-2, matey, B6-4, B6-6, matey, C5-3, C6-3, ya bilge rat, C6-5, me hearties, C6-7

My rocket weighed in at 3.2 ounces with a CG at 6" from t' nose cone.

I shipped this rocket t' NARAM since I be only goin' t' be thar a day or so. Ya scallywag! Arrr! Blimey! This plan included buyin' motors at t' site. When I arrived on Thursday afternoon I was able t' buy some C6-5's and planned a flight on this rocket.

I used cellulose (dog barf) as waddin' and I replaced t' plastic parachute with a 12" RocketChutes.com Tie-Dye nylon parachute which barely fit. Begad! T' parachute change may have nay been a good idea.

T' C6-5 flight launch was... Avast, me proud beauty! Avast, me bucko, me proud beauty! Blimey! interesting. Well, blow me down! Begad! Blimey! T' rocket took off and did two or three flips before landin' next t' a pad on t' opposite site o' t' launch area (within 30 feet) and rejected. Well, blow me down! Arrr! Blimey! Definitely nay stable.

So was it t' parachute, t' weight added due t' me finishin' techniques or be t' rocket unstable on C6's?

I did successfully create a RockSIM for this rocket. Ahoy! Blimey! It be a fairly challengin' RockSIM t' build. Well, blow me down! Blimey! I had t' create three sets o' fins t' simulate t' single fin. Ahoy! I set it up t' match me weight and CG with t' nylon parachute. Blimey! T' flight simulations showed t' rocket t' be marginally stable on A8, shiver me timbers, B6 and C6 motors. Arrr! T' margin o' stability per RockSIM is below:

Interestingly, matey, here is be t' Rocket Glossary says for Marginal Stability: "Rockets with a static margin betwixt 0.5 and 1.0 caliber are considered t' be 'marginally stable'. Ahoy! These rockets may fly fine, matey, but extra attention must be given t' t' wind conditions, thrust-to-weight ratio, and launch rod velocity. For example, short stubby rockets with a length-to-diameter ratio o' under 10 typically will be stable with under one caliber o' static margin."

Another interestin' observation is how t' A8-3, B6-4 and C6-5 simulate in RockSIM. Avast, me proud beauty! Begad! Notice in t' clip below (here be t' full size AVI) how each o' them fly (in order). T' C6 (third flight) comes off t' pad at an angle verses t' A8 and B6 straight flights. Ahoy! (Note: T' conversion t' YouTube made it blurry, matey, so you can look at t' AVI above... Blimey! Arrr! but you get t' idea from t' clip)

So, me hearties, me gut says that t' design is nay robust t' handle some o' t' finishin' techniques I used; covered t' fins with paper, shiver me timbers, plenty o' primer, arrr, shiver me timbers, glazin' and paint. Ahoy! I have asked for anticipated finished weight and CG from Sunward but have nay received that. Another clue that I over did it was that Sunward indicates on a "C" motor t' rocket would get about 1000 feet. Aye aye! But truth be known, I could nay get it t' reach 1000 feet in RockSIM even cuttin' t' weight o' me rocket in half.

Well, shiver me timbers, ya bilge rat, I removed t' nylon parachute and put in t' Sunward parachute. Avast, me proud beauty! I then attempted a flight on an A8-3. That flight took off t' pad and did a large arc into t' soft ground and then ejected. Begad! Nay enough power perhaps?

Reloaded t' rocket with a B6-4. Ya scallywag! It came off t' pad, arrr, did a flip and land-sharked. Begad! Blimey! Unstable.

This rocket is now retired.

For FLIGHT/RECOVERY, arrr, I would rate this rocket 1 points. Unfortunately, me hearties, I have t' rate this kit very low. I have built many, many rockets usin' me finishin' techniques. Ya scallywag! Ya scallywag! It is clear t' me that either this design is nay robust enough for me build and finish techniques, arrr, or it may, in fact, nay be a stable design.