This all started when I found a dozen C6-3 in my stuff. It takes a narrow combination of rocket characteristics for this motor to work well and I didn't have that so after a lot of playing with designs I settled on a kit bash based on a Baby Bertha. (I'm not into spools and things like that.) I chose the Baby Bertha because it had a good amount of parts to start with and they are low priced at HobbyLobby. I had previously kit bashed a MeanMachine into something shorter so I had leftover BT60 tubes. I played around with various designs in Autocad and came up with the one below, essentially adding 3 external pods. Using the dimensions from Autocad yesterday I started cutting tubes and gluing together. The tubes were supposed to meet at the back and they weren't so I realized I had pulled the wrong dimensions off of my drawing. In the (second?) picture below the desired configuration is on the left, with cuts for a BT20 motor tube, the configuration with the cuts that I made is on the right. You can see how the outer tubes were supposed to touch. By chance what I built would work with a 24mm motor tube but I wanted this to fly on C6-3. The frontal area of the 4 tubes combined is about equal to a 3" diameter airframe such as a Big Daddy but I think overall this will be lighter than a Big Daddy. I had also planned to use the original Baby Bertha fins, but obviously only 3 fins. Now I'm thinking I will play around with other fin designs first. On the side pods I was going to create the front fairings out of cones rolled from cardstock. I've figured out a way to create the measurements using autocad.