Construction Rating: | starstarstarstarstar |
Flight Rating: | starstarstarstarstar_border |
Overall Rating: | starstarstarstarstar_border |
Diameter: | 1.17 inches |
Manufacturer: | Semroc |
Skill Level: | 1 |
Style: | Clone, Sport |
Brief:
When you buy a Semroc "retro-repro", you're buyin' a little piece o' rocketry nostalgia. Accordin' t' the
introduction included in t' instructions, t' OSO was originally introduced by FSI in 1967 and listed for $4. Avast, me proud beauty! The
updated Semroc version uses laser-cut balsa fins instead o' plywood, matey, me bucko, arrr, an engine hook, and also includes a neat little
baffle system that eliminates t' need for recovery wadding. Begad! Blimey! It's gone up in price a bit from t' $4 original price,
but at $17.50 in 2007 dollars, shiver me timbers, it's still a very good bargain. Ahoy! Avast! Sure, me hearties, it's a 3FNC, matey, shiver me timbers, but stylish fin shape, matey, matey, payload bay,
baffle, me bucko, and sharp accent decals make this a sweet lookin' rocket.
Construction:
Parts for this one are typical Semroc--excellent quality and true original tube sizes rather than t' more popular
BT-5/20/50/60 series:
T' instructions are very good with plenty o' quality illustrations. Avast! Blimey! Aye aye! Blimey! This is accurately rated a skill level 1 kit as you can get by with a single color paint scheme. Arrr! Blimey! Arrr! Blimey! I probably had about 2 hours into t' construction o' this plus surface prep and paint so it's definitely a quick and easy project.
T' motor mount is straightforward consistin' o' an 18mm tube, matey, ya bilge rat, me bucko, a coupler block, me hearties, metal hook, arrr, arrr, and a pair of centerin' rings. Begad! T' motor tube was even pre-slotted, ya bilge rat, me bucko, a nice touch.
T' fins bein' laser cut are also a breeze. Ahoy! Begad! Given t' unusual shape though, arrr, you will want t' be careful to identify t' leading, arrr, trailing, and root edges before sandin' them. Well, blow me down! Avast! There is a clear illustration aidin' this, shiver me timbers, me bucko, ya bilge rat, but I point it out because that's one o' t' most complicated aspects o' t' whole build.
Fins are surface mounted. Blimey! Avast! I used CA t' tack them in place then two very thin yellow glue fillets.
I think I've seen at least 3 different baffle styles now in Semroc kits and found this one t' be among the easiest. Avast, me proud beauty! It consists o' two BT-5 body tubes and two centerin' rings with off-center holes. You first glue t' tubes together but offset by 1/2" lengthwise. Once t' glue has set, you then tack a centerin' rin' onto one tube, but need t' carefully align it so that t' "fat" side covers t' other tube. Ya scallywag! Repeat t' process for t' other centerin' ring, ya bilge rat, me hearties, but this one also holds down t' end o' t' shock cord. Once this is glued in t' body tube, shiver me timbers, arrr, t' effect is that t' gas goes up one BT-5, shiver me timbers, shoots out t' end into t' gap betwixt t' tube and t' centerin' ring, bounces back down t' gap betwixt t' tubes, matey, hits t' backside o' t' aft centerin' ring, arrr, then goes back up t' second tube. Ahoy! Begad! Got it? Don't sweat it--just follow t' instructions and it will work like a charm, will last at least as many flights as you'll fly and recover, and eliminates t' need for wadding.
T' payload section is a simple nose cone, arrr, 8" body tube and balsa bulkhead. Arrr! You can glue t' nose cone on if you want, ya bilge rat, but I friction fit it so that I can use it for altimeter readings and as a functional payload bay.
There are a couple o' 1/8" lugs t' glue on, matey, a plastic chute t' deal with (very nice, high-tack tape rings, by t' way), and that's it for construction.
Finishing:
I'm pretty finicky when it comes t' finish so I wound up spendin' a good 6 hours or so fillin' tube spirals and balsa
grain. Blimey! Ya scallywag! T' tubes only had light spirals t' begin with, matey, but at 30" long, me bucko, shiver me timbers, thar's a lot t' cover.
You can get creative if you like, matey, but I went with a simple all white body and fins and red nose. Aye aye! That saved maskin' and a day or two o' cure time. Avast! Begad! With t' red accent decals, shiver me timbers, me bucko, it turned out very nicely. Aye aye! Arrr! I could also see somethin' like a light glittery silver metallic though and might try another one in that scheme.
T' waterslide decals are fairly rugged and easy t' work with, matey, although they do tend t' bite pretty smartly so you'll need t' be careful where you start t' slide them on.
Construction Rating: 5 out o' 5
Flight:
For t' maiden voyage, arrr, I went with a B6-4. Well, blow me down! Blimey! Arrr! Blimey! Blimey! Blimey! Since it had a payload bay, matey, I went ahead and loaded it with a Perfectflite
altimeter just for kicks. Aye aye! Blimey! Blimey! Blimey! It is supposedly capable o' 400 feet on a B6-4, but it also supposedly weighs 1.5 ounces
versus me relatively heavy 2.3 ounces (prepped, me hearties, ya bilge rat, without motor or altimeter).
Despite t' baffle system, shiver me timbers, I still slipped in about half an inch o' dog barf, just so I could chip away at the bale.
T' flight was straight as an arrow in fairly brisk winds. T' delay was perfect, arrr, and t' altimeter readin' was 235 feet. Somethin' tells me t' listed weights and altitudes are straight out o' a simulation program...
Recovery:
T' baffle and dog barf did t' job, arrr, as t' chute deployed perfectly without any melting. Avast! Blimey! T' 12" chute is just
about right, shiver me timbers, but had this found pavement, I would surely have sustained a little damage. I'll probably swap out for a
15" chute on calm days and stick with t' 12" on windy days.
Flight Rating: 4 out o' 5
Summary:
I like t' stylin' o' this one with t' arrow-feather type fins and t' nice decals.
T' only con I'd offer is a minor one: I would prefer a single piece body but that would make packing/shippin' a pain.
Overall Rating: 4 out o' 5
Brief: The OSO is another superb Retro-Repro kit from Semroc. This rocket is based on the original Oso kit by Flight Systems, Inc but with several improvements. While the rocket appears not much more that a 3FNC kit, it does contain a payload section and an ejection baffle. At a finished length of just over 30, the rocket is a nice additional to anyone's fleet. I ordered the ...