It dried up enough that I could go outside and do some cutting and grinding again. I trimmed the lower airframe to size. At this point I also cut slots for the fins. This pretty much had to be done now while I was still able to use the CR to guide me. The fins will also have to be in place before the tanks, as the space between the tanks isn't large enough for the through the wall fins. They'll have to be trimmed on the outside. More on that later.
To make sure the fin cuts were straight, I used Mr. Macklin's fin guide. Even though it's not large enough for my tube, with a square and an aluminum angle I was able to make it work.
After cutting the slots (I'm getting a lot better with the cutting wheel!), I taped the fins into place just so I could feel I was making progress, and to see how it looks. Not bad.
I'm starting to think about the tank fairing now. At it's core, it's a simple transition with holes cut for the tanks. This site (
https://meatballrocketry.com/saturn-construction-tips/) has a good description for how to make the holes, but I'm thinking it's just an ellipse. I'll try an ellipse pattern later to see how it works. I'll start with the transition first, and then cut and trim the tank slots after it's in place.
I started in rocksim to design the transition and printed the template.
This is on plain paper, so excuse the lack of stiffness. I tested the fit and it looks ok. To make this in CF I have a few options. One is to put some ribbing in place and cover that. That's not a good plan here because the tanks get in the way, so any ribbing would be so minimal as to be useless. Another would be to put a temporary structure in place (such as foam core), layup the CF, and remove the frame. I haven't fully discounted this. Another method would be to build a stand alone frame, lay the CF on that, trim to fit, and glue into place. I'm tending towards that option as my experience with CF is one of frayed edges. Making it over sized and trimming gives me a better margin for error. Any thoughts from the forum?
As a final note, and a warning to anyone tempted to work with carbon fiber, wear your PPE, and don't do this in your living room! I showered just before I started this part!
Cleanliness is over rated!