Re: May the fun begin


Tim Dixon
 

Yeah Mike, hotels are kinda out of the question right now per my doctor.

Had to take a bit of a redirect on the build as I slipped and fell during the ice storm doing a number on my back/ribs. So instead of trying to manhandle the bulky fin can while dealing with spasms, I decided to move to a smaller item/task, the av-bay mechanics. This delay was OK though as after doing a fit of the booster airframe, I decided to go a different direction on the attachment points; upgrading to #10 pan head screws for more surface area, so awaiting a parts delivery on that change anyway.

So, the av-bay is nothing special. In fact, my general direction for this project has been to keep it as simple as possible. I did consider the use of Rouse-tech CO2 ejection, but given the low altitude, it was hard to justify, especially given max black powder is "only" 6 grams due to the large surface area of the bulkheads. I say "only" because, although I have never used that much BP in my life, I have seen some of the QCRS guys using 6 gram charges in airframes of half the diameter, albeit a fiberglass airframe that could survive such a shock.

So the following pictures should be pretty familiar and explanatory. Actually, the real trick in this step was dealing with the inherent slop in the Sonotube dimensions. Since this is one of the two critical slip joints, I had to finesse a couple of more layers of fiberglass laminate to get a more accurate fit. After that, minor adjustments were also required on the bulkhead pairs which was done with a combination of a router pass and some light sanding. Hardware is all 3/8-16 which is sized for the weight and gee forces expected. Outside of that, believe me, I am a recovering over-builder, so am trying to use the minimum of epoxy and reinforcement throughout this and every build I've done for the past 10 years. Saying that I do have reinforcement at critical stress areas, e.g., the bulkhead hardware attachment point where I'm using a swatch of 10oz Kevlar. The fairly large charge holders may or may not be familiar--you can get this large size and a number of smaller sizes at dirt cheap prices by searching for "pill canisters" on eBay. Finally, on the aft bulkplate you see an aluminum plate for the antenna attachment. I now have that drilled for with #2 hardware in the four corners, and the wimpy antenna shown will probably be upgraded to something more stout given the space I have in the airframe. Finally, the last picture is after adding labels and a thin layer of epoxy for ding durability and ease of cleanup.

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