I have a BT-60 Booster, very easy assembly for C11-0 & D12-0 rocket motors and it's a perfect compliment for the Estes Mix-N-Match 60, or BT-60 A.R.F. and E2X models Flying Colors, Firestorm, Fractured, Spectra, Rookie and Helios, but more can be done with this booster. 3 Nice Rockets; Parts lists: 3x BT-60 boosters, PNC-60A( 3 nosecones), 2x BT-60 body tubes 3packs, for 6 body tubes, 3x BT-60 body tube couplers, 80 lbs. stranded nylon fishing line, PS-ll Shock cord, 3x 18 parachutes, 1 tongue depressor, 1 popsicle stick, CA and epoxy adhesive. Assembly: 1. Get a Booster 60 and remove the short, red and glossy BT-60 tube glued to the top, do not attach fins yet. 2. Scuff the top of the red plastic mating area, until a BT-60 body tube will mount firmly and flush on the plastic coupler mounting, but do not attach yet. 3. Cut a piece of nylon stranded 80lbs, fishing line, depending on what length of the rocket you decide. 1 full length BT-60-(457mm), or 2x 457mm=(914mm) + Booster-60-W/BT-60 red paper stage coupler removed-(97mm)+ nosecones, varying in length, but no longer than 213mm, the same nosecone for the Estes Star Orbiter. So adding these lengths together for a total length of 914+97+213=1224mm a little bit longer than 1/2 the length of Estes Mean Machine. Or add 457+97+213=767mm, a little shorter than Estes Hi-Flier XL. I like the stranded nylon fishing line shock cord 5x to 6x the length of the rocket, plus 150mm of PS-ll shock cord, so 5x1224=6120mm, or 6x767=4602mm total length, plus 150mm of PS-ll shock cord, 3 assembled BT-60 body tubes are too much tube for the red fins, unless you can print,or customize larger plastic fins, stick with only 2 BT-60's, for a maximum length. 4. Drill a hole in the top of the fin can, focusing cone end, using an 3mm drill bit, on top of the motor mount going into the motor mount 5mm from the outer diameter and not interfering with the fin attachment, or focusing cone 5. Tie the end of the nylon shock cord into a knot, or knots large enough not to pass through the hole just drilled and epoxy the knot and pass through the fin can so the fin can will hang like it will once the parachute is deployed, epoxying it in place. 6. Lightly scuff fin attachment and epoxy fins in place. 7. Pass shock cord through the engine mount hanging out the bottom of the rocket, this will insure you don't accidentally glue the to the side of the tube and assemble tube lengths, with 1 BT-60 coupler, epoxy together 2 BT-60's. When fully cured, draw a straight line down the full lengths of both tubes. This for the launch lug attachment. 8. Attach air frame to fin can, with epoxy, aligning the line drawn 1/2 way between the fins. When fully cured, pass shock cord back through fin can, exiting the top of the air frame .9. Attach parachute lines to the nose cone anchor, attach one end of PS-ll shock cord to the free end of the stranded nylon fishing and the other end of the PS-ll shock cord to the nose cone. 9. Your C/G will vary depending on your air frames final length, so swing balance with motor and wadding installed, before attaching launch lugs. Draw and cut 13mm off the end of the wooden tongue depressor and then cut evenly, perpendicular to the wood grain 2x 6mm strips, as launch lug spacers. Cut a launch lug in 1/2 and attach both halves to spacers, with epoxy. 10. When cured, install one at the closest point, to the fin can, still on the body tube and attach the other 25mm ahead of the determined C/G, both along the line drawn and let cure. Use a launch 3/16 launch rod to ensure proper alignment and they do not bind. Only add nose weight, when necessary for stability. 11. After lightly sanding around potential fin fillet area, build up epoxy fillets on fins, launch lugs and spacers with the popsicle stick and let cure. 12. Paint, let dry, add decals, let dry, 13. 5,4,3,2,1 launch. The shorter one will go over 1,000 feet on a D12-5 and the longer one will see about 700 feet. Have fun with these easy mods.