Due to things like homework, tennis lesson, extreme tiredness, and all-around apathy, I haven't gotten much done in the lat few days, much less any building.
However, this evening I've gotten a little bit done with the Viper IV.
First, I sanded the fins. This didn't take very long. 240-grit sandpaper smoothed out the flat faces of the fins very nicely, and for the edges I just used a few strokes of 120-grit, then steel wool, which gave it a nice shiny-smooth surface.
Next I started assembling the motor mounts by gluing together 2 pairs of tubes, then adding fillets on the side that will be the inside. (The outside doesn't get fillets yet, because I still have to attach the fins).
To make the launch lug a little better, I put CA on the ends, preventing the cardboard from unraveling.
Finally, I started wotk on the motor retention system. I found a washer that's big enough to hold the motors and still not deflect the thrust, and a way to attach it to the threaded rod. Then I glued two nuts to a pair of motor tubes and spaced them with the threaded rod. Once i use a little epoxy clay to hold them in place, the motor retention system will be downright bulletproof.
Blegh... back to my English essay now, which is due tuesday.