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" 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 Crepe streamer
• 1 Tape disc
• 1 Empty engine casing
• 1 Glue applicator
• 1 Decal sheet

The instructions included with the kit are in a logical order and easy to follow. Each step is accompanied by a clear diagram, and templates are included by the diagram of the step they are needed in.

Assembly is easy, with no real problems. Everything fit perfectly! The whole rocket is quite sturdy and would survive a recovery failure. I built mine with Medium CyA but the instructions suggest white/yellow glue.

I didn't really do anything different from the instructions, but on a rocket this simple there isn't really anything you can do differently.

Finishing:
Finishing this bird can be as simple as you want it to be! There are two decals supplied with no set place to put them. I decided to paint mine Florescent Orange all over--I want to find this thing again!--with 3 coats of white primer, 3 coats of orange, and then 3 coats of clear lacquer on the top to maximize the effect of the paint.

Construction Rating: 5 out of 5

Flight:
The recommended motors are any 13mm motor from 1/4A3-3T to a full on A10-3T.

Prepping consists of inserting the igniter in the motor, friction fitting the motor, then pushing 3-4 sheets of recovery wadding down the tube. I found it quite difficult to roll up the streamer small enough to fit in the tube but managed it on my second try.

First flight was on a A10-3T with light winds (3-6mph). This rocket is very quick off the pad! After ignition, there was a neck snapping fast boost and ejection was just before apogee.

Second flight was on a A3-4T with light winds (3-6mph) again. This time the boost was slightly slower but longer. I almost lost it on the way up but the tracking smoke started up. Ejection was almost spot on apogee but the tape disc holding the streamer on came loose. The rocket tumbled down from 700ft, however, it landed with no damage. The streamer took about 10 minutes to come down although it landed surprisingly close to the pad. I've now fixed it back on with some masking tape.

Recovery:
PROs:

• Nice long shock cord
• Effective crepe streamer
• Good descent rate
• Rocket survived coming down with no streamer without damage!

CONS:

• Streamer attachment method

Flight Rating: 4 ½ out of 5

Summary:
I think this is a great rocket from Semroc!

PROs:

• Easy to build
• Great flights
• Amazing quality materials

CONs:

• Streamer attachment method

Overall Rating: 5 out of 5

Brief:
Very affordably priced single stage, 13mm minimum diameter kit. Very high performance--it will zip up to incredible altitudes almost instantly. This is actually a Semroc original, not one of their retro/repro Centuri designs.

Construction:
The kit came sealed in a plastic bag with a header card and included a serial number identifying its production number. 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
• Kevlar®/elastic shock cord combo
• Crepe paper streamer
• Motor block
• Waterslide decals
• Motor casing, Q-tip glue applicator

Yes, this kit includes a motor casing (actually just a plain cardboard tube) and a Q-tip for applying glue up inside the body tube. Not bad for a $5 kit and that makes this a very good project for Cub Scouts and school groups. Cheap, easy, and includes the little gadgets to simplify construction that most of us experienced builders take for granted. This kit is definitely something that can be built in under an hour, plus paint/finish time. The instructions were clear, have plenty of good illustrations, and everything fit fine.

Being a minimum diameter kit, there's no motor mount assembly to work on. Instead, you just glue a motor block inside the body tube. Even though I usually use scrap balsa for this, I though it was neat that they included a Q-tip for this application. Keep in mind though that before gluing in the motor block, you must first tie the Kevlar® shock cord to the block. I really like the Kevlar® but this looked a bit light (maybe 90#) and I'm curious how it will stand up to repeated flights.

Fin preparation is pretty easy, since the fins for this (and all Semroc kits) are laser cut. After a light sanding, they're ready to bond to the body tube. There are 3 fins attached at the standard 120-degree rotation. Be sure to apply a good fillet on these, as the fins are tiny and there is a lot of stress when flying this on an A10.

The nose cone is a standard balsa nose with screw eye anchor. No additional nose weight is needed on this. This was a very nice balsa cone. Semroc really packs quality and value into their kits.

Construction wraps up with the attachment of the crepe paper streamer. It's a nice orange 1" wide streamer, although I think the small tape disk/dot for attachment is pretty flimsy so I upgraded mine to heavy masking tape at the base.

Finishing:
The instructions do a nice job of detailing out how to properly seal balsa; suggesting up to 3 coats of sanding sealer. I cheated and went with a single diluted coat of Elmer's Fill 'n' Finish, which I sanded down with 240 grit sandpaper.

After sanding down a coat of gray primer (used mainly to fill spirals), I followed up with a white primer base, then two coats of gloss white. The illustration on the 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 needing a lot of coats to cover up basic pencil marks or base coats. I found a can of safety/dayglo yellow though and decided to give it a shot. It looked GREAT and only needed a couple of coats. The bright yellow really stands out.

The kit also includes a set of water slide decals, which I think are an excellent addition to this kit. It would look fairly boring otherwise, but with the decals it almost looks like a bee.

Construction Rating: 4 ½ out of 5

Flight:
First flight was on a fairly windy day, approaching 8-10 mph. I went with a 1/2A3-4. Despite the wind, this raced absolutely straight up and cooked to easily 400 feet. The streamer rolled out right over apogee and everything came back in great shape.

I have since flown it in calmer winds on A3s and A10s, both of which take it out of sight. For full As, I recommend using tracking powder to make sure you can spot it. Tempera paint powder makes great tracking powder as does crushed chalk (from a home supply store).

Recovery:
Perfect flights, no problems whatsoever.

Flight Rating: 5 out of 5

Summary:
I've built a bunch of Semroc kits now and this one is one of my favorites. It's a great value, easy to build, and flies out of sight on a $0.75 motor. It doesn't get much better than that.

Overall Rating: 5 out of 5

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 Crepe paper streamer
• 1 Tape section
• 1 Empty engine casing
• 1 Q-tip
• 1 Decal sheet

This is a relatively simple kit to build. The instructions are straightforward and easy to follow. As this is a minimum diameter body tube that is quite long, there are some precautions to take:

• Read the instructions first. It is a simple kit, but it does have a couple pitfalls if not careful.
• Do not over glue the thrust ring. I let one of the neighbors build one and he got the thrust ring stuck about 1/2inch into the tube. He used too much glue and could not overcome the friction while trying to insert the thrust ring to the proper depth.
• If you push too hard on the thrust ring, you can easily crumple the body tube. If you are building this kit with children, this might be a step for the adults to do for them.
• The kit suggests rounding the fins, which is not a bad idea for bigger fins, but on this kit, they are fairly thin already so it doesn't seem to make that much difference.
• In building a set of seven (with two failures) we tried CA, wood glue, and instant glue. It really didn't seem to mater all that much. All flew well and have held up for multiple flights.

The only thing that we did differently on construction was to fit the thrust ring without glue then glued it in place using the Q-tip provided.

Finishing:
There is a small decal sheet and the only real direction for finishing is the color cover that is a standard part of all Semroc instructions. I did one as factory as possible, then did a couple variations. I would highly suggest using colors that you can easily detect in a natural environment. Paint it white or blue, you will lose it in the sky. If you paint it green, camo, or any colors that exist in outside, then make sure you have plenty of spotters or some good eyes. Day-Glo or neon colors seem to work best (unless you live someplace very odd).

Construction Rating: 4 ½ out of 5

Flight:
Since the engines were relatively cheap and readily available at my local hobby store, I bought a retail case and just kept launching and launching the different variations of the kits. (All flights used A10-3Ts.) In retrospect, some of the smaller engines might have been nice to try as this thing moves out on an A10-3T!

I tried a variety of different motor retention techniques and even tested motor ejections to see if it would impact recovery. My favorite method of positive retention is to use a 1/3 of an inch of masking tape just wrapped around the body of the engine. This was strong enough to hold the engine in place on every launch.

Prepping the rocket is straightforward but is a bit difficult as the tube diameter is so small. Using a pencil really aids in sliding the shock cord and wadding in.

All flights were very straight with arcs at apogee.

Recovery:
This rocket uses the "standard" Semroc small diameter shock cord. A length of Kevlar® string tied to the thrust ring. In turn the other end of the Kevlar® is tied to an elastic cord which is then secured to the screw eye attached to the nose cone.

The crepe paper streamer is pretty long and can be a bit difficult to pack into the body tube. In testing, this rocket will recover with no streamer and recovers very gently with only half a streamer.

Flight Rating: 4 ½ out of 5

Summary:
This is a very fun kit! It is easy and fast to build, cheap to feed, and gets some great height in a short period of time. I chuckle every time I launch the ThunderBee, it's just one of life's small pleasures. It's diminutive size belies a real fast mover. On 1/4A or 1/2A engines, I could see this being a nice back yard rocket. On the full A10, make sure you have some space.

Overall Rating: 4 ½ out of 5