Brief:
This is a scratchbuilt anti-zipper design with interchangeable MMT/fin assemblies.

Construction:
Main BT with payload and 3 fin design. It is anti-zipper and can change from a single motor to a 3-motor cluster in only a minute! Uses a center ring to separate payload from chute compartment. I needed to add extra weight in payload for clustered assembly. Uses quick links, eye bolts, and tubular nylon for strength.

I used plywood for fins with through the body assembly. Don't skip on glue--epoxy is better! After first launch just a little black on fins but no damage! Also, use nylon chute! Save yourself some aggravation. I got mine at NARAM 51 from Sunward but any good chute will do. Biggest trick is to mount your coupler in main body so can change out fin assemblies. Build all fin assemblies with baffles so you don't need wadding.

Flight:
I went for it on first attempt with 3 D12-5s. I wouldn't use any less of delay. I had long shock cords! You connect one to any eyebolt in main body with a quick link, add a piece of tubular nylon two times longer than rocket, then another quick link (this one gets the parachute), and finally another short piece of tubular nylon connect to the eyebolt in your baffled MMT/fin assembly. Make sure you use plenty of epoxy in motor mounts! You can extend life of insides by spraying chute compartment with fire resistant paint used on BBQ grills.

Summary:
Fun rocket to launch! Use a Clip Whip, as it's the only way to go. Biggest pro is quick and easy disconnect of different fin assemblies from 1 motor to 3 engine cluster.

You might want to make it a little longer than 2 feet to avoid having to add weight. Besides that, there's not a thing wrong with it! Makes life easy if you fly in different fields and a cluster too much for one but great at the other!