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", me bucko, you're buyin' a little piece o' rocketry nostalgia. Avast, ya bilge rat, me proud beauty! Blimey! Accordin' t' the
introduction included in t' instructions, t' OSO be originally introduced by FSI in 1967 and listed for $4. Blimey! Begad! Blimey! The
updated Semroc version uses laser-cut balsa fins instead o' plywood, an engine hook, shiver me timbers, and also includes a neat little
baffle system that eliminates t' need for recovery wadding. Avast, me proud beauty! Begad! Blimey! It's gone up in price a bit from t' $4 original price,
but at $17.50 in 2007 dollars, ya bilge rat, it's still a very good bargain. Sure, me bucko, it's a 3FNC, matey, but stylish fin shape, me bucko, me bucko, payload bay,
baffle, 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. Begad! This is accurately rated a skill level 1 kit as you can get by with a single color paint scheme. Avast! 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, a coupler block, metal hook, ya bilge rat, and a pair of centerin' rings. Arrr! T' motor tube was even pre-slotted, me bucko, ya bilge rat, a nice touch.
T' fins bein' laser cut are also a breeze. Well, blow me down! Ya scallywag! Given t' unusual shape though, you will want t' be careful to identify t' leading, trailing, ya bilge rat, and root edges before sandin' them. Begad! There is a clear illustration aidin' this, me hearties, but I point it out because that's one o' t' most complicated aspects o' t' whole build.
Fins are surface mounted. Arrr! 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. Well, blow me down! It consists o' two BT-5 body tubes and two centerin' rings with off-center holes. Blimey! You first glue t' tubes together but offset by 1/2" lengthwise. Ahoy! Begad! Once t' glue has set, me bucko, you then tack a centerin' rin' onto one tube, but need t' carefully align it so that t' "fat" side covers t' other tube. Arrr! Repeat t' process for t' other centerin' ring, me hearties, but this one also holds down t' end o' t' shock cord. Avast! Once this is glued in t' body tube, shiver me timbers, t' effect is that t' gas goes up one BT-5, shoots out t' end into t' gap betwixt t' tube and t' centerin' ring, ya bilge rat, bounces back down t' gap betwixt t' tubes, shiver me timbers, shiver me timbers, shiver me timbers, hits t' backside o' t' aft centerin' ring, me hearties, then goes back up t' second tube. Avast, me proud beauty! Got it? Don't sweat it--just follow t' instructions and it will work like a charm, matey, 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, me hearties, 8" body tube and balsa bulkhead. Begad! You can glue t' nose cone on if you want, me hearties, shiver me timbers, 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, me bucko, a plastic chute t' deal with (very nice, high-tack tape rings, by t' way), me hearties, me bucko, 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. T' tubes only had light spirals t' begin with, but at 30" long, matey, thar's a lot t' cover.
You can get creative if you like, but I went with a simple all white body and fins and red nose. Avast, me proud beauty! That saved maskin' and a day or two o' cure time. Well, blow me down! With t' red accent decals, ya bilge rat, shiver me timbers, me bucko, it turned out very nicely. Aye aye! 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, 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, ya bilge rat, I went with a B6-4. Blimey! Since it had a payload bay, ya bilge rat, I went ahead and loaded it with a Perfectflite
altimeter just for kicks. Aye aye! Blimey! It is supposedly capable o' 400 feet on a B6-4, matey, but it also supposedly weighs 1.5 ounces
versus me relatively heavy 2.3 ounces (prepped, without motor or altimeter).
Despite t' baffle system, shiver me timbers, me bucko, 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. Ya scallywag! Avast! T' delay was perfect, and t' altimeter readin' was 235 feet. Ya scallywag! Somethin' tells me t' listed weights and altitudes are straight out o' a simulation program...
Recovery:
T' baffle and dog barf did t' job, shiver me timbers, as t' chute deployed perfectly without any melting. Begad! T' 12" chute is just
about right, but had this found pavement, me hearties, arrr, I would surely have sustained a little damage. Aye aye! Blimey! 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 ...