boatgeek
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I've been teasing a few things in the "what did you do" threads, and I finally have enough done to kick off a build thread. This is another rocket from Boatgeek's House of Weirdball Rockets(tm): a mid-power rocket with a spruce airframe. I'm also taking a crack at making this rocket have no metal parts whatsoever, which (IMHO) is pretty tricky for a mid-power bird. Whatever else, this needs to fly FAR 101 so that I can fly it regularly. Keeping it under 1500 grams fully loaded will be a trick.
The airframe is made with a boatbuilding method for making hollow spars: the bird's mouth. I'm using an 8-sided tube that looks like the one shown in Calculator #8 on the page linked above. I won't round this one, so it will stay octagonal. That lets me use a thinner wall, in this case, about 5/16" (0.31").
I completely blew the calculations for how much wood I needed, so I grossly overbought. This is a truly magnificent piece of Sitka spruce in the back of my van. The unfinished wood is about 2" x 7" x 10'. I'm using about 4' of the wood for body tube, nose cone, and couplers. Another 2' went to my daughter's boyfriend for Valentine's Day, and the remainder will become 2 paddle blades for our canoe.
A friend who also works with our high school rocketry club has far better woodworking equipment than me. After trips through a bandsaw to cut into strips, a jointer to smooth, a thickness planer to get even thicknesses, and a table saw with dados for the bird's mouth, we have 8 pieces that look like this:
and here's my friend working hard at the jointer:
I taped the outside faces with masking tape to protect them from the glue and then turned them into a roll sort of like a roll top desk. This let us just paint the glue on to the bird's mouth and then roll it all up at once instead of trying to do things piecemeal. That was a good thing, because we nearly ran up against the cure time of the epoxy.
Here's the roll of wood, followed by it all glued up. The white is parchment paper. The pens taped to the side help push all of the wood tight, and are held in by electrical tape since you can pull tension on electrical tape pretty well. That worked out well though I had some spots that didn't quite get enough glue. I probably should have applied the glue with a syringe instead of a little paintbrush.
The airframe is made with a boatbuilding method for making hollow spars: the bird's mouth. I'm using an 8-sided tube that looks like the one shown in Calculator #8 on the page linked above. I won't round this one, so it will stay octagonal. That lets me use a thinner wall, in this case, about 5/16" (0.31").
I completely blew the calculations for how much wood I needed, so I grossly overbought. This is a truly magnificent piece of Sitka spruce in the back of my van. The unfinished wood is about 2" x 7" x 10'. I'm using about 4' of the wood for body tube, nose cone, and couplers. Another 2' went to my daughter's boyfriend for Valentine's Day, and the remainder will become 2 paddle blades for our canoe.
A friend who also works with our high school rocketry club has far better woodworking equipment than me. After trips through a bandsaw to cut into strips, a jointer to smooth, a thickness planer to get even thicknesses, and a table saw with dados for the bird's mouth, we have 8 pieces that look like this:
and here's my friend working hard at the jointer:
I taped the outside faces with masking tape to protect them from the glue and then turned them into a roll sort of like a roll top desk. This let us just paint the glue on to the bird's mouth and then roll it all up at once instead of trying to do things piecemeal. That was a good thing, because we nearly ran up against the cure time of the epoxy.
Here's the roll of wood, followed by it all glued up. The white is parchment paper. The pens taped to the side help push all of the wood tight, and are held in by electrical tape since you can pull tension on electrical tape pretty well. That worked out well though I had some spots that didn't quite get enough glue. I probably should have applied the glue with a syringe instead of a little paintbrush.
