Brief:

This is a free plan downloaded from Apogee's newsletter E-zine web site (issue #91). It's a very nice, basic modroc, which I'd rate at about a skill level 2-3. It features two sets of fins, with the larger set mounted Forward of the smaller set for an unusual appearance.

Construction:

The Parts List comprises:

• 24mm nose cone
• 24mm (BT-50) tubing 13.5"
• 18mm motor mount kit with 18-24mm centering rings
• 12" parachute/shroud lines
• Shock cord (1/8" elastic at minimum, I used 1/4")
• 1/8" launch lug
• 1/8" balsa or basswood fin stock (I used balsa)
• Clay for nose weight (about .25 oz)

There are no instructions provided with this free download, but its basic design is easy to assemble if you've got some previous experience. If you have the full version of Rocksim, you'll want to print out the fin patterns, as this is much easier than drawing them from the dimensions.

Construction is fairly simple. Start by making a motor mount out of 18mm tubing with a couple of centering rings. Optionally use a metal engine hook, though I use friction fit on 18mm motors, so went without the hook. Mount the motor mount in the BT50, cut out the fins, tack using CA, fillet the seams with wood glue, install the recovery device, and add enough nose weight to get the CG about 10.5" from the nose of the rocket.

Finishing:
The Shrox design depicts a two-tone red on white paint scheme, including white tips on the mostly red fins. I went with that approach, and also added a basic decal "SNIPET" for identification (printed on my inkjet with Avery clear decal paper).

Construction Rating: 4 out of 5

Flight:
There were no recommended motors, so I played around on Rocksim and came up with A8-3, B6-4, and C6-5 as the best motors. First flight was with a B4-4 on a day with steady 15mph winds. The rocket weathercocked a bit, but otherwise flew very well. I suspect I went a bit heavier than necessary with the nose weight, as I was a little conservative flying a "plan" instead of a "kit". The delay was slightly early, though I think moving to a 6 would have been a bit late. The rocket was recovered safely with no damage, and is now sitting in my ever-growing box of Shrox/Apogee plan birds.

Recovery:
Not the best rocket for a windy day, I'd back off on the nose weight or fly under 10mph winds.

Flight Rating: 4 out of 5

Summary:
My only suggestion for improvement would be a simple decal or two for a better overall appearance.

Overall Rating: 4 out of 5