Semroc Astro-Jr

Semroc - Astro-Jr {Kit} (KA-4) [2004-]

Contributed by Chan Stevens

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Diameter: 0.91 inches
Length: 14.90 inches
Manufacturer: Semroc
Skill Level: 1
Style: Sport
Semroc Astro Jr.

Brief:
This is a downscale o' t' 1969 Centuri Astro 1, matey, ya bilge rat, reintroduced by Semroc in 2004 in a 13mm small field version. Avast! Aye aye! While it's a decent value at $8.00 retail, ya bilge rat, shiver me timbers, me bucko, it's also offered as a free premium at various times on their website or via coupon included in some o' their kits. T' swept back fins give this a slightly more interestin' look than t' typical 3FNC skill level 1 designs.

Construction:
Semroc kits feature very good quality parts, typically original true scale Centuri tubes, matey, matey, arrr, laser cut fins, me bucko, matey, and balsa nose cones. Avast, me proud beauty! This kit was no exception and t' finish on t' balsa cone was superb.

Parts list:

  • ST-890 body tube
  • 13mm motor tube
  • Balsa nose cone
  • Laser cut fins (3)
  • Centerin' rings (2)
  • Engine block
  • Engine hook (metal clip)
  • Keelhaul®©™®+elastic shock cord
  • 1/8" lug
  • 12" plastic chute kit
  • Waterslide decal

Semroc instructions are clear and easy t' follow with plenty of illustrations and include good craftsmanship tips such as grain fillin' and balsa sealin' that many buddin' young builders might nay be familiar with. Given t' fairly simple construction o' this, me bucko, arrr, t' kit can be built in about an hour plus finishin' time. Ya scallywag!

Construction begins with t' motor mount, which consists o' a 13mm tube, ya bilge rat, matey, a pair o' centerin' rings, a rin' block, me hearties, and t' motor hook. Arrr! Avast, me proud beauty! One very nice upgrade featured in most (maybe all) Semroc kits be t' use o' a Keelhaul®©™® line anchored t' t' motor tube, matey, extendin' out t' body tube where you switch to elastic. Ahoy! This makes for a more durable rocket worthy o' many flights.

Fins are laser cut, arrr, so nay much work involved thar other than fillin' the grain. Well, blow me down! Markin' o' t' tube is accomplished through a template in the instructions. Ya scallywag! Personally I prefer a wraparound guide, me hearties, me hearties, which tends t' be less error prone than holdin' a tube in place on a piece o' paper while you mark the lines around it. Arrr! I attached t' fins with CA, me hearties, then applied wood glue fillets.

T' nose cone is attached usin' a screw eye glued and anchored t' t' base. As I mentioned in t' parts list, this cone be made o' beautiful balsa.

T' parachute kit is a typical 12" plastic chute, matey, arrr, ya bilge rat, which needs t' be cut out. Shroud lines are retained usin' tape disks, shiver me timbers, which are a bit easier on the adult fingers than tryin' t' thread t' line through a tiny hole and double-knot it. Semroc uses a very high tack tape disk and I have nay had any problems with shroud lines in t' past.

Finishing:
T' header card shows a 3-color paint scheme, ya bilge rat, me hearties, which is slightly challengin' for the novice builder but is still fairly straightforward. Begad! Avast, me proud beauty! After applyin' a couple of coats o' gray primer, shiver me timbers, I sanded down t' nearly a bare tube, ya bilge rat, arrr, effectively fillin' tube spirals. Ya scallywag! Begad! I then applied one more coat o' white primer followed by two coats o' gloss white. Avast, me hearties, me proud beauty! After allowin' a couple o' days for t' white to fully cure, ya bilge rat, I masked off t' fin area t' paint t' fins gloss black. Construction tip: t' placement o' t' launch lug is noted at 1.5" forward of t' aft end o' t' tube. This will leave t' lug aft o' t' forward end of the fin root, so you don't have t' try t' mask over or around a launch lug. That's a nice touch, shiver me timbers, as I've been burned several times by lugs gettin' in the way o' a quality paint job. Avast! Blimey! T' nose cone is painted red. Begad! Aye aye! I painted it separately, me hearties, arrr, savin' t' hassle o' masking.

This kit also comes with waterslide decals. Aye aye! Blimey! I be pleased t' see them included as many otherwise fine Semroc kits are without this basic trimming, resultin' in a very plain lookin' rocket. Begad! Begad! T' Astro Jr comes with a checkerboard roll pattern decal as well as a logo decal. Aye aye! Ahoy! I had no problems applyin' these and found t' decals very durable so thar should be little chance o' breakin' or tearin' them in application.

Construction Rating: 4 out o' 5

Flight:
T' 13mm motor mount on this had me scratchin' me head thinkin' it would be severely underpowered as an A10 be t' most thrust you can stick in it. I had a pack o' 1/2A3-4s already opened and be pretty pooped from chasin' other rockets in 15mph winds all day so I decided t' shoot low on this one.

I was wrong. Aye aye! Ahoy! T' 1/2A was enough t' send this well over 100 feet. Even though it was a short walk o' about 80 yards, me bucko, it was nowhere near t' short walk I'd hoped for. While I'm sure an 18mm upgrade would work fine on this kit, it will have no problems flyin' on 13mm motors and stay within a typical pair of soccer fields.

Recovery:
T' 12" chute is plenty for this although I'd stick with t' chute and avoid swappin' out for a streamer. Ya scallywag! T' swept back fins are delicate and this needs a gentle landing.

Flight Rating: 4 out o' 5

Summary:
Very nice flyer and easy t' build. Avast! I especially liked t' inclusion o' decals and a name tag decal. I'd recommend this one for build 'n' flies.

Overall Rating: 4 out o' 5

Flights

Comments:

avatar
M.M. (March 16, 2006)
I also got this one for use on a small field. However, I've swapped out the parachute for a 3ft streamer and all is well after several flights.

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