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. Blimey! I thought t' center tube looked really interesting. 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. Begad! T' plastic nose cone uses clay nose weight. Begad! Avast, me proud beauty! There are four laser-cut balsa fins and two laser-cut centerin' rings that are used for t' center tube. Ya scallywag! T' kit includes an 18mm motor mount with a retainin' hook. 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. Arrr! There is a fin markin' template that needs t' be cut out from page 2 o' t' instructions. Ahoy! They include illustrations t' assist in t' build.

Sunward calls t' kit a Skill Level 2 and we agree. It is a fairly easy kit t' build, arrr, however, arrr, shiver me timbers, with t' fit o' t' center tube and t' fins around that tube, 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. Avast! So before gluin' them in place, I coated each side with Modge-Podge and placed a piece o' newspaper over them. Ahoy! Blimey! Then place them betwixt wax paper and under heavy books. Ahoy! 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... caps. Begad! Avast! In other words, matey, they do nay fit inside t' center tube t' ensure that it is centered, shiver me timbers, they sit on t' outside and t' center tube has t' be aligned t' be even with these caps. 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. Then they have you glue t' center (larger diameter) tube t' that cap, me hearties, followed by t' second cap. Avast, matey, me proud beauty! Blimey! I was 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. Well, blow me down! Next, shiver me timbers, me hearties, I'll tell you what I did, however, me hearties, it should be noted that followin' t' instructions will work.

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

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

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

Once t' CA was dry, ya bilge rat, I added a fillet o' glue t' t' outside o' t' top and bottom caps.

All t' fins fit nicely around t' central tube, arrr, however, I had t' sand t' root edges t' ensure that they set "down" onto t' central tube. Ahoy! This took a bit o' work t' have them fit nicely. Aye aye! Avast! Once done, ya bilge rat, each fin be able t' be glued into place.

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

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

T' kit didn't come with decals. Begad! Aye aye! Interestingly, this could be a really neat lookin' rocket if it was painted white with black fins. Avast! Then if thar were some port-hole decals on t' center tube. Arrr! You get t' idea.

Overall, ya bilge rat, for CONSTRUCTION I would rate this kit 3 points. Blimey! Begad! 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! Avast, me proud beauty! Had t' one little issue with t' 3-fin template when it was supposed t' be a 4-fin template. Begad! T' instructions are just okay and no decals.

FLIGHT/RECOVERY:

Sunward recommends t' followin' motors: A8-3, A8-5, matey, B4-2(first flight), me hearties, B4-4, shiver me timbers, B6-2, me bucko, me hearties, B6-4, B6-6, arrr, C5-3, me bucko, C6-3, me bucko, C6-5, me bucko, 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. This plan included buyin' motors at t' site. Ya scallywag! When I arrived on Thursday afternoon I be 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. Ya scallywag! T' parachute change may have nay been a good idea.

T' C6-5 flight launch was... Arrr! interesting. Arrr! 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! Avast, me proud beauty! Definitely nay stable.

So was it t' parachute, ya bilge rat, 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. It was a fairly challengin' RockSIM t' build. Well, blow me down! I had t' create three sets o' fins t' simulate t' single fin. Begad! I set it up t' match me weight and CG with t' nylon parachute. T' flight simulations showed t' rocket t' be marginally stable on A8, me hearties, B6 and C6 motors. Ya scallywag! Arrr! T' margin o' stability per RockSIM is below:

Interestingly, here is was 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'. Arrr! These rockets may fly fine, but extra attention must be given t' t' wind conditions, ya bilge rat, thrust-to-weight ratio, arrr, and launch rod velocity. Well, blow me down! Ya scallywag! For example, matey, 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. Notice in t' clip below (here be t' full size AVI) how each o' them fly (in order). Arrr! Avast! T' C6 (third flight) comes off t' pad at an angle verses t' A8 and B6 straight flights. Ya scallywag! (Note: T' conversion t' YouTube made it blurry, shiver me timbers, so you can look at t' AVI above... Avast, me proud beauty! Ya scallywag! but you get t' idea from t' clip)

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

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

Reloaded t' rocket with a B6-4. Begad! Well, blow me down! It came off t' pad, did a flip and land-sharked. Begad! Unstable.

This rocket is now retired.

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