Brief:
This is a very unique futuristic space-plane design, featuring round (semi-oval) fins and aping-pong ball in the mid section. For a free plan (Ezine #93), this is quite impressive and presents a challenge to most builders.

Construction:

• 24mm nose cone
• 24mm body tubing 13.5" long
• 29mm body tubing-2 pieces, each 2" long
• 18mm motor mount
• (2) 18-24mm centering rings
• Streamer--2x48 Mylar
• Shock cord (1/8 elastic or 90-100 lb Kevlar®, roughly 36" long)
• 1/8" launch lug
• 3/32 balsa or basswood fin material
• Decal sheet (can print from the available .jpeg download)
• (1) ping pong ball. Yes, a ping pong ball.

There are no instructions for this free download (RockSim is also available here on EMRR), though most anyone with skill level 2 experience can muddle through this with few problems. Start by assembling the motor mount, then cut the fins (the newsletter included templates, which can also be printed through Rocksim). Next, mark the body tube for 2 sets of fins mounted at 120 degree angles. Tack on the fins with CA, then apply fillets of wood glue. The (2) short 29mm tubes are mounted at the aft end of the rocket, on top of two of the fins.

Since the ping pong ball slides over the BT50/24mm tubing, you have to cut holes for this. To pull this off, hold a body tube on top of the ball and trace the outline, then carefully scribe and cut out the hole using a sharp knife. Repeat the process for the other side, being careful to align the holes on opposite sides of the ping pong ball. Slide the ball down the body tube to about 1" above the fins and glue in place.

Finishing:
Seal & sand the balsa, followed by two coats of primer, followed by two coats of glossy white finish paint. I printed out the decals on Avery clear decal paper using an inkjet printer, which is a slightly dull/opaque finish. Water-slide decals would be much better if you can find an affordable source or have the equipment.

Construction Rating: 4 out of 5

Flight:
The first flight was using a B6-4 (no motor recommendations provided) with steady winds of about 15mph. The rocket veered off on an unstable trajectory, and was recovered safely. I then added about 0.2 ounces of nose weight, and the subsequent flight was straight up.

Recovery:
Definitely need to verify the CG on this one compared to the Rocksim file before flying.

Flight Rating: 3 out of 5

Summary:
This is a great-looking rocket, and once I corrected the stability problem, it flies wonderfully. Of course, having bought a 6-pack of ping pong balls, I now find myself wondering what other similar designs I can come up with to deplete my stock of spare parts...

Overall Rating: 4 out of 5