Time for another update. I’ve filled the spirals in the false motor tubes and sprayed primer on them to check for missed spots. The photo below shows the end with the fin alignment guide on and the first two fins tacked in place.
Here is a view with all the fins tacked in place and the alignment tool removed.
Next I began pouring 30 minute epoxy down the fin roots to get them firmly attached. This took a while since I could really only effectively do two fins at a time. Then I needed to let them set up so I could rotate the airframe and do another two. Also, since I needed to get epoxy down both sides of the fin roots, it still took seven rotations to get them all done. Here is a look down from the end. The lighting is bad so you might not see much epoxy but it is there.
After all the roots had cured I more or less repeated the process to be sure that I got a good joint all the way down. I then needed to pour fillets for the fins where they meet the dummy motor tubes. I used some clay to plug the end and keep the epoxy from running out and all over the motor tube.
I then poured epoxy into the area and made sure the tube was barely in a nose up attitude. This allowed the epoxy to flow and level without all of it leaking down the front of the fin. I did make sure that some epoxy did flow down the front edge of the fin into the void below. That made for a nice smooth fillet line from the leading edge to the trailing edge.
I then mixed some epoxy with microballoons to make a paste that I could use to fill the voids between the dummy motor tubes and the main motor tube. The picture looks ugly, but when looking at it by eye it is relatively smooth. I’ll see what it looks like when I spray primer over the whole bird later.
Next I need to start working on the nose cone and then can come the painting. Maybe I’ll be ready for a test flight in August?
More work has been done on the Wild Thing. I drilled four small holes through the motor tube and into the 5/8 inch plug. I then epoxied 4 short sections of dowel into the holes. These will serve two purposes. First, they will provide a bit of an additional anchor for the plug to prevent it coming loose during recovery. Admittedly a small chance but why risk it. They will also prevent me from pushing the forward end of the baffle too far down the motor tube.
I then used the bulkhead I’m not using to mark the fin positions. This will help me get the fin alignment correct.
I then pushed it on to the back of the rocket over the 38mm motor tube.
Next, it was time to epoxy the motor mount assembly into the main tube. I first marked on the outside the position of each of the centering rings. This would help me figure out where to smear epoxy on the inside so I would be sure to push the ring through the epoxy on its way to its final position. Since there were three rings on this motor mount, I needed to smear epoxy for the top ring first. Once I had it smeared all around the inside of the tube I started pushing the motor mount in. Before the next centering ring went inside the tube, I smeared its epoxy inside the tube. Then continued pushing the mount in until I was nearing the last ring. This ring basically fits flush with the end of the main tube, so I smeared epoxy at the end of the tube. I then pushed the mount in the final amount. Once that was done I stood the rocket up on its business end as vertical as I could get it. I was using 30 minute epoxy for this, so I let it cure for a couple of hours before I laid the rocket over.
Now I needed to glue in the upper baffle bulkhead. I mixed up about 10ml of 30 minute epoxy and put my rubber gloves on. I smeared a bit of epoxy just above where the bulkhead was to go and then pressed the bulkhead into place. I then used a finger and scooped out some epoxy from the cup and smeared it around the tube/bulkhead joint. I also smeared some around the motor tube/bulkhead joint. I again stood the rocket up vertical until the epoxy had cured.
I then installed the rail buttons. The lower button was screwed into the centering ring at the base of the main tube. The upper button was installed just above the upper baffle ring.
I need to fill in the spirals on the dummy tubes. I could have glassed them but that would have made it difficult to get them installed on the centering rings, and made it harder to get the fins on. It won’t be too bad to get them filled. Then it will be on to the fins. I’ll start by rounding the edges. Then they will get glued in according to the alignment ring I made. Anyway that will be a future update. That’s it for now, thanks for looking.