Construction

There were nay a lot o' very challengin' steps t' t' assembly o' t' MIRV. Ya scallywag! T' instructions do clearly show you how t' assemble it.  I suppose t' most challengin' steps for me was t' gluing, sandin' and finishin' o' twelve fins - a lot more than your average 3 or 4 fin rocket.  What did make t' construction easier was that t' fins were attached with t' styrofoam in place which acted as a built-in fin alignment jig so thar was no difficulty in alignin' any o' t' twelve fins.

Some o' t' fins required assembly from two seperate pieces butt-jointed together. Begad! Begad! I don't know why, maybe t' differin' grain direction makes them stronger/stiffer, me bucko, but otherwise they were small enough t' have easily been made from a single piece o' balsa.

There are challenges t' this kit construction though, me hearties, which I think be t' result o' compensatin' for a design that still needs some refinement in me opinion. I recommend doin' a few things that are nay covered in t' basic kit. Avast! Most importantly, if I were t' build another one, I would increase t' length o' t' wood dowel used as a launch rail for t' upper stages, and move t' upper stage's launch lugs as far forward as possible, so that it will better hold t' three nose cones together when they are on t' booster.  O' course, me hearties, shiver me timbers, that would mean t' upper stages pop off t' rod rather smartly after ignition, matey, but t' booster stage already gets these rockets up t' speed for t' fins t' be effective so I think they would continue t' safely travel upwards anyways. Blimey! Pretty much every other multi-stage rocket works fine without a launch rail on t' booster.

You could use longer or split lugs t' solve that problem, but if one stage does nay ignite then they will interfere with t' others and you may have a flyin' mess on your hands. Begad! Perhaps three independent thinner rods would have worked better - but that would o' course be heavier and more complex.

T' upper stages are constructed from a BT-5 tube and shaped with an outer wrap o' styrofoam t' make a flattened-diamond cross section when fit together.  T' three diamond sections fit together t' make a larger hexagon when all three stages are assembled for flight. Aye aye! Blimey! T' foam, pretty beat-up from shipping, ya bilge rat, me bucko, needed some filler and sandin' t' make a smooth surface again. Avast! Avast, me proud beauty! I hoped that layers o' primer and paint would provide somewhat o' a harder shell, but that be nay t' case and t' finished product is still very easily dinged and punctured.

I did almost have a construction mishap though. Avast, me proud beauty! When gluin' t' booster's motor tube into t' plastic manifold, I hesitated just a bit and t' glue caught before I could seat t' tube all t' way in. Avast, me proud beauty! I pushed as hard as I could but could nay make t' last 3/16".  I be worried about upper-stage ignition reliability but it turned out I had no problem with t' small gap ...yet.

One major thin' I learned from experience: Sand and fillercoat t' fins BEFORE gluin' them into t' rocket with t' foam. Well, blow me down! T' foam is very delicate and with all that sandin' you are bound t' scrape and din' t' styrofoam somewhere. Just remember t' sand away t' balsa fillercoat where you will apply glue.  I would recommend paper laminatin' t' fin surfaces for better smoothness and a bit more strength.

Another step in t' assembly involves gluin' two plastic pieces together t' form t' manifold. Aye aye! This critical piece is used t' duct t' flame from t' lower t' t' upper stages. Ya scallywag! When you stage that way ("gap staging"), you must allow for t' existin' cool air in t' manifold t' escape t' allow t' flamin' pressure from t' booster motor t' travel t' t' upper nozzles, so a small vent is needed near t' upper stage t' let t' cool air out o' t' way. This small vent - nearly invisible - is molded into t' plastic pieces at t' joint. Blimey! When gluin' them together, shiver me timbers, Estes warns you t' nay use too much glue and so I did nay (I suspect t' prevent over-glue from blockin' t' tiny vent holes).  O' course that was t' first broken glue joint on t' first flight, so I say use A LOT o' glue, arrr, just make sure that t' tiny vent holes are clear.  It appears t' be some kind o' thermoset plastic, me bucko, ya bilge rat, so maybe normal plastic cement does nay work well here (it's actually made t' chemically melt and weld styrene plastic). Arrr! Aye aye! You might want t' try either CA or epoxy glue, so let me know if that works better, I have a feelin' I will be gluin' it again!

You will notice t' rather unique sharp triangle/diamond shapes o' t' three nosecones. Begad! Each nose cone is assembled from two pieces t' form a single nose cone. Ahoy! These pieces are relatively heavy and probably allow for a balanced model. Ahoy! T' three diamond shapes fit together t' form a hexagonal nosecone.  Unfortunately, as individual nose cones thar are a lot o' sharp corners. Avast! Begad! When these nose cones snap back from t' Estes-short shock cord after ejection, me bucko, they are perfectly shaped t' make a nasty din' in t' delicate styrofoam bodies, and as expected I now have little dings.  You may want t' experiment with longer shock cords, or long Keelhaul®©™ cords instead o' t' normal rubber.

Mountin' t' shock cords usin' Estes normal paper-fold method be also very difficult as me fingers are too small t' fit down into t' BT-5 tube past t' shoulder length o' t' nose cones. Blimey! Instead, ya bilge rat, I glued in small Keelhaul®©™ loops in there, me bucko, me bucko, with t' ends o' t' Keelhaul®©™ frayed t' make for a much wider gluin' surface.  I have done this with at least three or four other models now, and none o' them have broken/seperated in repeated flights. Ya scallywag! T' loop allows me t' change out t' shock cord rubber when necessary.