Tonight I worked on the electronics bay sled. For altimeters, I'm going to use a Missleworks RRC2L and an Eggtimer Quantum. Both of the altimeters have been used successfully for previous launches in other rockets.
For switches, I'm going to use 6-32 screw switches with covers/guides that I got from Missleworks. I'm planning to use a switch for the Quantum even though it will still be armed via Wi-Fi. For batteries, I'm using a pair of 2s (7.4V) 800mah lipos (one for each altimeter). The batteries are wrapped in bubble-wrap and held in place with zip ties.
I haven't done the bulkheads yet, but, for those I'm planning to use 1/2" PVC caps as my charge wells with euro style terminal blocks for the e-match connections. I will post pictures of the bulkheads once they are assembled.
I'm using JST connectors between the altimeters and the switches and the terminal blocks so that I can easily disconnect them as needed. In order to avoid improper connections, I'm color coding the wires near the JST connectors with tape. Red tape indicates power, blue tape indicates main, and yellow indicated drogue. I've planning to have 3 vent holes in the e-bay and I'm going to use two of them to access the screw switches. Below are some pictures with more details.
Here's the type of screw switch I'm using (before I add the cover/guide). Note that I've twisted and then soldered together the black wires and covered the joint with heat-shrink. The red wires are soldered to the switch on the other side.
Here are some pictures of the avionics sled. The arrows point toward the nose. I'm planning to do a bit more cable control, but, this shows the overall layout. One of the switches is mounted on the edge of the sled and the other on a pylon so that they will line up with 2 of the 3 vent holes. The piece of threaded rod has been added temporarily to be sure the zip ties didn't interfere with it. I mounted the altimeters using nylon standoffs and nylon screws. To install them, I drill the hole for the standoff threads and then tap it and then coat it with thin CA.