Building a Lunar Eclipse Jr. (part 2)

Tonight’s the night of the lunar eclipse. They said it would be a partial eclipse, but they were wrong. The moon was fully eclipsed:IMG_2136BY CLOUDS.

Nevertheless, I was ready to start building. During the week I moved my rocket building stuff into the basement from the garage. The garage isn’t heated, and winter’s coming. The basement doesn’t get quite as cold, and we’d moved a desk down there a few weeks ago, so I have a work surface.

I’m going to build this rocket almost unmodified, following the instructions. Which, I must say, could be better. As far as I can see, for instance, they don’t actually say anything about coupling the two body tube pieces together. Or gluing the aft centering ring into the body tube. Or attaching the elastic to the Kevlar. All of which of course is obvious to anyone who’s not a square one beginner, so not that big a deal. It looks like they do adequately describe the steps that are less obvious. (I’m looking at you, weird fins.)

At this point I think the one thing I’m going to change is to make the body tube coupler into a baffle, and I’ll anchor the Kevlar there. I started with building the baffle, using two plywood D plates.IMG_2132

I drilled a 1/16″ hole in one plate, applied Elmer’s yellow glue around the edge of one face, and set the coupler on it.IMG_2134

While that was drying I started on the motor mount. I didn’t follow most of the first step of the instructions, because it dealt with attaching the Kevlar to the motor mount tube. I did file a notch in the rear centering ring for the motor hook.IMG_2135

Now the instructions have you glue the forward centering ring onto the motor mount tube, but I decided to hold off on that. I slotted the tube for the motor hook, lined it up with an aluminum angle,IMG_2137

and taped it down with duct tape.IMG_2138

I put wood glue inside the tube just forward of the hook, and used a spent motor casing to shove the engine block into place.IMG_2139And then I glued the forward centering ring in place, and the aft one too. Here you can see how after marking the position I used a scrap of paper wrapped around the tube and taped to give me a reference line; you may also be able to see I roughed up the tube surface with 220 grit sandpaper before gluing.IMG_2142

Here’s the motor mount drying, with glue fillets on the rings.IMG_2147

Meanwhile the glue on the baffle had set, so I applied a layer of 5 minute epoxy to the aft face of the plate I’d glued, and to one face of the other plate.IMG_2144

When that dried I flipped the second plate over, applied glue around the edge, and put the coupler on.IMG_2148

And yes, I did eventually put that cap back on the glue bottle.


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