Brief:
Semroc Large Scale (SLS) reproduction of the Centuri Scorpion Space Probe from 1965.

Construction:
The kit includes:

• 1 body tube
• 1 engine tube
• 1 balsa nose cone
• 1 set laser cut fins
• 1 thrust ring
• 1 launch lug
• 1 screw eye
• 1 elastic cord
• 1 Kevlar® thread
• 1 nylon parachute
• 1 24mm engine mount
• 1 set decals

Semroc kits come with exceptionally high quality parts and clear instructions and the SLS line is no exception. The parts come in little Ziploc bags and assemblies are bagged together so you do not have parts lying all over the place during assembly. The first assembly is the 24mm engine mount/adapter which includes an engine hook for motor retention.

The engine tube is 29mm and is very sturdy with thick walls just like the main body tube. A large thrust ring is glued inside the main body tube along with the Kevlar® shock cord mount. One minor complaint is that there is no motor retention included for the 29mm motors, so you must use friction fit.

The basswood fins are laser cut and need very little sanding. There is a little typo on step 6 where it tells you to sand the "three fins". The kit actually includes four fins.

The body tube is already slotted to accept the TTW fins. The engine tube is just below the slots which gives the fins something to grip to. All that is left is to mount the launch lug and attach the nose cone and nylon parachute, which is already assembled.

Finishing:
Stock paint scheme is all white with a black nose cone. I chose to deviate a bit since I had some silver paint I needed to use up. The fins and nose cone are such high quality, I only needed one coat of sanding sealer to smooth things over. Two coats of primer and three colors later, the rocket was finished. Semroc includes very sturdy waterslide decals that were easy to apply.

Construction Rating: 5 out of 5

Flight:
Its only flight of the day was on a D12-5 using the 24mm engine mount. I used four sheets of wadding since I did not want to singe that pretty, bright yellow rip-stop nylon chute. Nice straight boost to about 1000 feet and the rocket was recovered with no damage. I am awaiting some F25 motors to give this rocket a real test. RockSim predicts almost 3600 feet on that motor!

Recovery:
The nylon parachute was just perfect for this rocket.

Flight Rating: 5 out of 5

Summary:
Semroc works hard to provide high quality kits at reasonable prices. The SLS line shows their commitment to high standards. The Scorpion flies great as an LPR and I can't wait to fly it as an MPR very soon!

Overall Rating: 5 out of 5

Brief:

The SLS Scorpion is Semroc's Large Scale (SLS) reproduction of the Centuri Scorpion Space Probe from 1965.

CONSTRUCTION: ( 5 out of 5)

I've only purchased a couple of rockets from Semroc, but I must tell you, I am very impressed with the quality of the kits in general and the way the kits are packaged. Packaging of the Scorpion is typical of most rocket kit manufacturers - parts in a plastic bag with paper header. But inside is where Semroc departs from the group (in a good way.) The pre-cut basswood fins are packaged in a separate zip bag, as were the nylon parachute, the engine mount parts and a bag of miscellaneous parts containing the smaller items that could easily get lost. Everything was accounted for; nothing damaged.

Parts List:

• 1 Body Tube
• 1 Body Tube
• 1 Balsa Nose Cone
• 1 Laser Cut Fins
• 1 Thrust Ring
• 1 Launch Lug
• 1 Screw Eye
• 1 Elastic Cord
• 1 Kevlar Thread
• 1 Nylon Parachute
• 1 24mm Engine Mount
• 1 Decal

Given that fact that the Scorpion is one of Semroc's SLS (Semroc Large-Scale Rocketry) line, I expected the parts to be a bit heftier than what you get in the normal model rocket kit. I was not disappointed. The main body tube was to my liking, a nice 0.05" thick and pre-slotted for the laser-cut through-the-wall fins. The nylon parachute has strong nylon shroud lines riveted to the chute at eight locations.

Instructions are top notch with clear illustrations and a very logical assembly order. The Scorpion did not need any templates since it is a basic four fins and a nose cone rocket. The exploded view in the centerfold is a nice touch complete with a Parts List and part numbers for all pieces.

The balsa nose cone is top rate, although you need to sand down the shoulder to fit the BT (something I found true of the other Semroc kits I've purchased.) The fin tabs fit nice and snug in the body tube slots and are aligned perfectly along the tube.

Finishing:

I primed the model with 2 coats of Krylon Primer and then followed up with 2 coats of color. I picked a Yellow/Orange scheme. Future floor polish was used for the final finish. The provided decal was not used.

FLIGHT/RECOVERY: ( 4 out of 5)

Semroc lists four recommended motors: C11-5, D12-5, E9-8 and F25-9. My flights were all on D12s, although I prefer the longer 7 second delay. Rocket prep is the usual: wadding, chute, etc. Since I was using the 24mm motors I needed to install the 24mm motor mount adapter which is included in the kit. The adapter contains a motor hook and so retains the 24mm motors well, but like the 29mm motors, the adapter must be friction fit into the body tube. Flights on the D12s were picture perfect - nice straight boosts and moderately quick.

The shock cord system is a combination of Kevlar thread and elastic cord. I built the kit stock, but would suggest replacing the elastic with a longer length of Kevlar.

OVERALL: ( 5 out of 5)

Semroc has produced a wonderful kit with the Scorpion. Once I visit a larger field I'll put the E8 in and she what she does!