Semroc Thunderbee

Semroc - ThunderBee {Kit} (KA-1)

Contributed by Chan Stevens

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Diameter: 0.54 inches
Length: 14.70 inches
Manufacturer: Semroc
Skill Level: 1
Style: Sport

Semroc ThunderBee

Brief:
Very affordably priced single stage, 13mm minimum diameter kit. Arrr! Well, shiver me timbers, blow me down! Blimey! Very high performance--it will zip up t' incredible altitudes almost instantly. This is actually a Semroc original, arrr, nay one o' their retro/repro Centuri designs.

Construction:
T' kit came sealed in a plastic bag with a header card and included a serial number identifyin' its production number. Avast, me proud beauty! Avast, me proud beauty! Components were all very good quality and included:

  • ST-5120 body tube (basically a BT-5)
  • Balsa nose cone/screw eye
  • Laser-cut balsa fins
  • 1/8" launch lug
  • Keelhaul®©™/elastic shock cord combo
  • Crepe paper streamer
  • Motor block
  • Waterslide decals
  • Motor casing, Q-tip glue applicator

Yes, this kit includes a motor casin' (actually just a plain cardboard tube) and a Q-tip for applyin' glue up inside t' body tube. Ahoy! Begad! Nay bad for a $5 kit and that makes this a very good project for Cub Scouts and school groups. Begad! Cheap, matey, easy, and includes t' little gadgets t' simplify construction that most o' us experienced builders take for granted. Ya scallywag! This kit is definitely somethin' that can be built in under an hour, plus paint/finish time. Begad! T' instructions were clear, me bucko, have plenty o' good illustrations, me bucko, and everythin' fit fine.

Bein' a minimum diameter kit, matey, ya bilge rat, thar's no motor mount assembly t' work on. Arrr! Arrr! Instead, you just glue a motor block inside t' body tube. Even though I usually use scrap balsa for this, I though it be neat that they included a Q-tip for this application. Well, blow me down! Keep in mind though that before gluin' in t' motor block, you must first tie t' Keelhaul®©™ shock cord t' t' block. I really like t' Keelhaul®©™ but this looked a bit light (maybe 90#) and I'm curious how it will stand up t' repeated flights.

Fin preparation is pretty easy, me hearties, since t' fins for this (and all Semroc kits) are laser cut. Ahoy! Arrr! After a light sanding, arrr, they're ready t' bond t' t' body tube. Ya scallywag! There are 3 fins attached at t' standard 120-degree rotation. Avast! Be sure t' apply a good fillet on these, matey, as t' fins are tiny and thar be a lot o' stress when flyin' this on an A10.

T' nose cone is a standard balsa nose with screw eye anchor. Ahoy! No additional nose weight is needed on this. Avast, me proud beauty! This was a very nice balsa cone. Arrr! Semroc really packs quality and value into their kits.

Construction wraps up with t' attachment o' t' crepe paper streamer. Begad! Well, blow me down! Blimey! It's a nice orange 1" wide streamer, although I think t' small tape disk/dot for attachment is pretty flimsy so I upgraded mine t' heavy maskin' tape at t' base.

Finishing:
T' instructions do a nice job o' detailin' out how t' properly seal balsa; suggestin' up t' 3 coats o' sandin' sealer. Avast! I cheated and went with a single diluted coat o' Elmer's Fill 'n' Finish, which I sanded down with 240 grit sandpaper.

After sandin' down a coat o' gray primer (used mainly t' fill spirals), shiver me timbers, I followed up with a white primer base, then two coats o' gloss white. Avast, me proud beauty! T' illustration on t' header card shows a yellow base. I've never really had much luck with Krylon yellow and unless it's over pure white I wind up needin' a lot o' coats t' cover up basic pencil marks or base coats. I found a can o' safety/dayglo yellow though and decided t' give it a shot. It looked GREAT and only needed a couple o' coats. Ya scallywag! Begad! T' bright yellow really stands out.

T' kit also includes a set o' water slide decals, which I think are an excellent addition t' this kit. Ya scallywag! Ya scallywag! It would look fairly borin' otherwise, arrr, ya bilge rat, but with t' decals it almost looks like a bee.

Construction Rating: 4 out o' 5

Flight:
First flight be on a fairly windy day, me hearties, approachin' 8-10 mph. Ahoy! Blimey! Blimey! Blimey! I went with a 1/2A3-4. Begad! Blimey! Despite t' wind, this raced absolutely straight up and cooked t' easily 400 feet. Ahoy! Blimey! T' streamer rolled out right over apogee and everythin' came back in great shape.

I have since flown it in calmer winds on A3s and A10s, both o' which take it out o' sight. Ya scallywag! For full As, matey, me bucko, me bucko, I recommend usin' trackin' powder t' make sure you can spot it. Avast! Tempera paint powder makes great trackin' powder as does crushed chalk (from a home supply store).

Recovery:
Perfect flights, no problems whatsoever.

Flight Rating: 5 out o' 5

Summary:
I've built a bunch o' Semroc kits now and this one is one o' me favorites. Aye aye! Aye aye! It's a great value, me hearties, ya bilge rat, matey, easy t' build, me hearties, and flies out o' sight on a $0.75 motor. Well, me hearties, blow me down! It doesn't get much better than that.

Overall Rating: 5 out o' 5

Other Reviews
  • Semroc Thunderbee By Craig Swinson

    Brief: This is a very light, quick build kit from Semroc that is essentially a 3FNC but with some head snappin' zip when matched with the right engine! Construction: The parts list: 1 14.7" length of BT-5 1 Balsa sheet of laser cut fins 1 Balsa nose cone 1 Cardboard thrust ring 1 Launch lug 1 Screw eye 1 Elastic cord 1 Kevlar ® thread 1 ...

  • Semroc Thunderbee By Philip Handley

    Brief: The Thunderbee is one of the latest kits from Semroc. It's the first and smallest rocket in the "Thunder" family. Each rocket in the family is around 1.5 times larger than the rocket before it! The Thunderbee is a minimum diameter 3FNC rocket. It comes down on an orange crepe streamer. Construction: The Thunderbee comes with the following parts: 1 14.7" ...

Flights

Comments:

avatar
S.G. (February 27, 2008)
This was one of my first kit builds after getting back into rocketry after a 25 year hiatus. The quality is outstanding and was very happy with the way it all went together. I have flown this around 6 or 7 times now and have lost the streamer on a couple of flights (landing without damage). The heat from the motor has started to cause the paint to bubble.

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