I’ve been a little distracted and have not been posting as regularly as planned. I’ve more or less finished the main build. Since the last post, the rocket has been filled, primed, sanded, and painted. It’s hard to tell from the image below, but the darker color is a navy blue.
After putting some paint on the rocket, I epoxied the motor retainer on with some JB Weld. I went with an Aeropack retainer. Overall, the fit and finish of the retainer was great. I’m a little frustrated with the price of it though.
Now that the bulk of the build is done, I switched my attention to the altimeter bay. I decided to run redundant altimeters for the dual deploy. I ordered an Eggtimer Quantum for the primary, and a Perfectflite StratoLoggerCF for the redundant flight computer. The Eggtimer came as a kit, which was easy enough to solder up without a problem. The instructions were very detailed.
I took a look at the Madcow supplied altimeter sled and figured I could do much better on my own by 3d printing a custom altimeter sled. A few hours of 3d modeling got me to my first prototype. The overall goal of my design was to make this as customized as possible, but also make everything accessible. I’ve already spent more on this rocket than I’d like, so I want to be able to easily swap components out for use in other rockets. I’ll probably need another iteration to get all the sizes ironed out and places for wire tie downs, but it’s pretty close.
I went with a pair of 2S LiPo cells, 450 mAh, that are isolated from the flight computers by a pair of fairly hefty microswitches. The switches are turned off by inserting a 1/4″ rod through a tubing section printed in the sled itself. When fully assembled, the rod will go through the altimeter vent hole in the side of the rocket.
The first print off the printer turned out pretty close. I have some holes I need to resize, I need to add some holes to tie down some wires, but it is probably one iteration away from being ready. Once I’m happy with the print in PLA, I’ll probably switch to ABS or maybe even try NylonX.