Kit Specifications (from Cover Art)

• Length: 20" (508mm) Sustainer, 23" (584mm) Total
• Diameter - 1.0 inches (25mm)
• Weight - 0.92 lb (1.47 oz) (42g) *
  
• Skill Level 2

Background:
Nick at EMRR sent me this kit when I became a Featured Reviewer for EMRR. This was my first experience doing a staged rocket, as well as my first experience building a US Rockets kit.

The kit is packed in a standard clear plastic bag with a paper hang tag.

Parts List

• 1 BT-9-12 Airframe Tube
  
• 1 BT-9-5 Payload Tube
• 1 BT-9-3 Stage Tube
• 2 TC-9-3 Couplers
• 1 PP-9 Payload Plate
• 1 SE-0 Screw Eye
• 2 BT-7-2.75 Motor Tubes
• 4 CR-9-7-1/4 Centering Rings
• 3 Miniroc Fins
• 3 Fire Forget Fins
• 1 SCM- Shock Cord Mount
• 1 SC-5-1/8 Shock Cord
• 1 SM-3 Streamer
• 1 NC-9 Nose Cone
• 1 LL-1/8-2 Launch Lug
• Instructions
• AR 2B Decal Sheet
  
• AIR-3 Tech Report
  

The tubes are thicker than Estes BT-50, and have a smooth white glassine finish with minimal spiral. The pre-cut plywood fins had some fuzzy edges that clean up easily with a little sandpaper. The tube couplers are not standard brown kraft paper; they have the same white glassine coating as the body tubes. The shock cord is a very generous 55 inches long.

My kit was missing the Shock Cord Mount (easily re-created from a piece of paper), and I got an extra launch lug.

The instructions are printed on four 8.5x11-inch pages on orange paper. The directions have lots of text and a goodly number of computer-generated illustrations.

CONSTRUCTION

Construction is relatively straight-forward, and this would probably be a Skill Level 1 kit if not for the staging.

The first step is to taper the edges of the precut plywood fins with sandpaper. Next, the body tubes are marked using a marking guide (not the wrap-around kind, though), and the lines are extended using a door jamb. Then the fins are glued to the body using wood glue. I used the G. Harry Stine double-glue method with Titebond-II wood glue. To ensure that the upper fins lined up with the lower ones, I temporarily connected the two stages using the stage coupler and a used engine, then used a straightedge clamped to one fin to align the other fin.

After the fin joints have dried, the launch lug is cut in half and glued against the base of the fins.

Motor mounts are built for each stage using BT-20-size tubes along with two centering rings each. The spacing of the rings is somewhat non-standard and must be done correctly to allow the stages to mate properly later. The directions explain this clearly.

The motor mounts are glued into the body tubes and a stage coupler is glued into the lower body tube with 1 inch protruding out the top.

A standard tri-fold paper shock cord mount is used to anchor the shock cord to the bottom half of the sustainer. It is important that it be inserted at least 1.5" deep into the tube, since the upper stage shoulder is at least that long. I recommend inserting it even deeper than that to make it easier for the streamer to deploy cleanly.

The payload section is constructed from a 5-inch piece of body tube, a plywood bulkhead, screw eye, and a tube coupler. A pink plastic streamer (looks like construction site ribbon, 3" x 45" x 0.004") is taped to the shock cord between the sections. (I glued and stapled mine to ensure that it stayed attached.)

Finishing:

Finishing is pretty standard: Sand, seal, sand, seal, sand, prime, sand, paint. I skipped the sealer and used a single thick coat of Kilz primer to fill the grain and spirals, sanded most of it off, then a light coat of Rustoleum Painters Choice white primer.

The directions recommend painting the booster flat black and the sustainer fluorescent colors. I used a Rustoleum Fluorescent Red-Orange on most of the model, and Rustoleum Painters Choice Flat Black on the nose, one fin of each stage, and a band on the payload bay.

FLIGHT/RECOVERY

Recommended Motors

Flight Preparation

Here are the steps for flight preparation:

1. Apply masking tape as needed to assure proper fit of nose cone, stage coupler, and payload bay.
2. Insert recovery wadding.
3. Fold and pack the shock cord and streamer.
4. Insert payload bay.
5. Temporarily insert the upper-stage motor and check the balance point. It should be at least 1 inch forward of the leading edge of the sustainer fins. If the CG is behind that, add weight to the payload bay to move the CG forward.
6. Tape the two engines together using a single wrap of cellophane (Scotch) tape. [This step is not called out in the directions, but I think it is prudent.]
   
7. Insert the engines into the upper stage.
8. Wrap a layer of masking tape around the upper engine and the upper engine mount tube. Do not let this tape overlap the lower engine.
   
   
9. Slide the booster stage over the lower engine.
10. Wrap a layer of masking tape around the lower engine and lower engine mount tube. Trim excess tape.
    
11. Check the balance point again with both stages loaded. It should be at least 1.4 inches forward of the booster/sustainer seam. If the CG is behind that, add weight to the payload bay to move the CG forward.
    
12. Insert igniter and plug.
    
    

Test Flights

The next two flights occurred on a breezy day late in July, with winds from 5 to 10 MPH. Flight #2 used a B6-0/B6-6 combination. After a straight takeoff, it angled into the wind a little bit. There was a brief wiggle when the second stage lit, then the upper stage angled into the wind a bit more. Ejection was a bit after apogee. The large streamer deployed well and carried it downwind across two soccer fields and nearly into a men's soccer game in progress.

To prevent the wrath of a few dozen sweaty soccer players, I decided to angle flight #3 into the wind about 5 degrees when I moved up to a C6-0/B6-6 combo. The longer burn of the C6-0 was much more satisfying than a B6-0, and the B6-6 lit perfectly. It did quite a bit of weathercocking and headed out of the soccer field and over some apartments on the upwind side of the field. Fortunately, the wind carried it back over the apartments to the grass at the edge of the field.

On both flights the booster landed on the same fin and on both flights the fin-body joint got cracked, even though the grass was quite soft. For flying over hard surfaces, it might be a good idea to replace the streamer with a parachute.

Flight Rating:4 ½ out of 5

OVERALL:
A good solid performer that should be able to handle a lot more impulse than I dared to feed it.

PROS:

• Sturdy components.
• Clean styling.
  

CONS:

• Prepping requires heavy use of masking tape.

Overall Rating: 4 ½ out of 5