3DR Solo Dual Charger

This project came about thanks to information posted by members of the 3drpilots forum. Information and source for most of the electronics required for this build can be found at Grant Conery's excellent Instructables write-up -- http://www.instructables.com/id/GM-Multi-Solo-Charger/. His multi-charger build is also here - http://www.thingiverse.com/thing:1496497

As I don't go through very many packs when I fly, I went with a dual charger setup. Having a 200 x 200 mm print bed also dictated the maximum dimensions for the project.

I have a bunch of 2.5 mm self-tapping screws in various lengths so most of the internal components are held in with those. The terminal strip and the feet/cover plate are M3 screws. The housing is printed in PLA. I found that it holds threads very well if you start by using a tap for the first few millimeters and then just using the screw with a touch of lubricant on it.

The bi-color LED from the converter was removed and relocated in the case. Actually, the LEDs were destroyed in the process of removal so replacements were installed. The wires from the converters have female servo connectors on them and plug right into the LED's legs.

The housing for the plug slides together and snaps in place. There's a tab with slots for zip-ties to serve as a strain relief. Zip-ties are probably not necessary if the plug is installed in the case but it's there.

Instead of trying to print holes and mounts in vertical surfaces, I made slots in the housing for a fan and an XT60 connector for power input. The XT60 connector snaps into the two halves and the assembly slides into the cutout. The fan mount works the same way. The fan is a 25 x 25 x 7 mm unit from Amain Hobbies -- https://www.amainhobbies.com/hobbywing-25x25x7mm-2507sh12v-esc-cooling-fan-hwa86080020/p349371. It's small but pushes(or pulls) a lot of air. I have it configured as an exhaust fan. It's pretty loud. The fan mounting plate should be a fairly tight fit in the housing or it'll rattle and be even noisier than it needs to be.

The terminal strip is a 8 circuit Molex - https://www.arrow.com/en/products/0387700408/molex