The Estes Big Daddy first caught my eye hanging on the rack at WV Hobbies in the fall of 1998. It looked to me to be a good candidate for conversion to 29mm power, so I put it on my Christmas list. My request was granted, and away I went.
My first decision was to evaluate the kit parts to see what I would need for the conversion. I ended up keeping only the fins, body tube, nose cone, and main decals. I ordered a LOC 29mm stuffer tube from Magnum, and using fly cutters in my drill press, I made new centering rings from 1/8" birch ply. The motor retaining rods are 4/40 threaded rods, on opposite sides of the stuffer tube. I used a small round file to cut notches in the centering rings for the threaded rods, then everything was epoxied together and set aside to dry. A special note here is that I used the fins to position the centering rings, as I wanted the fin tabs to be a snug fit between the fore and aft rings. Although Dark Star motors have a lip on them, and many people use masking tape to make a thrust ring on other 29mm motors, I also glued a motor ring on the inside of the stuffer tube, just to be sure.
I glued the motor assembly in place using the fins for alignment. I cut 3/32" off the edge of each fin tab to get a tight fit against the body and stuffer tubes. Before gluing the fins in place, I saturated each one with thin CA, and let them set overnight before sanding them to remove the raised grain. I glued the fins in place with Pica Gluit - at which point, I hear you all gasping. Pica claims Gluit is stronger than epoxy ("Yeah, right!!" you say.) Gluit is thinner than epoxy, and wicks into wood grain and paper very well. I have complete confidence in its strength. But don't worry - I filleted each fin and centering ring with epoxy after the Gluit dried.
The entire rocket (except the NC, of course) was covered with .75 ounce glass cloth. A light mist of 3M 77 was used to hold the cloth in place, and Gluit was rubbed generously through the weave. An important thing to point out here is that I ALWAYS sand body tubes to remove the glassine covering; this helps the glue get into the fibers of the body tube better. Each set of ribs was covered with a single piece of glass cloth: from the tip of the rib, down across the fillets and body tube, and up to the tip of the adjacent rib. The top of the BT was covered with a single wrap of fiberglass. Gluit also sands well, without gumming, which left a smooth finish for the primer. I glued 1/4" launch lugs into one of the fin joints, and filleted them with epoxy and microballoons. After the minor imperfections that the primer revealed were filled and sanded, the entire rocket was painted with Krylon Hamm-r Tough Hunter Green, which gave a nice hammered metal finish. I also had several sets of Estes Wildfire decals, and I sliced these apart to create what I feel is a striking color scheme.
I added 3+ ounces of clay in the nose cone, held in place with another couple ounces of epoxy. The shock cord mount is a 3/16" eye bolt held in place by two nuts epoxied to either side of the top centering ring, and the shock cord is attached by a heavy-duty Swivel Eye Spring Snap from K-Mart's hardware section. Recovery is by a bright orange 30" Top Flite X-Form chute from Magnum.
Empty weight of the rocket is 17 ounces, and as those of you who were at the June 12 launch can attest, Big Wild Daddy gets airborne in a hurry on either an F62 Dark Star or G35 Econojet. I look forward to future such conversions - can you see a Big Bertha flying on Aerotech D21's?