Hey CD! In anticipation of tall robots, here’s a bottom loaded battery mount for fun and center of gravity reasons. Onshape Link: Onshape
The original goal with this design was to create a solution for putting the battery as low and out of the way as possible in the robot, while still being easy to change (sub 30sec).
The basic design is as follows.
In the ready position, 6 standoffs and the side walls of the polycarbonate tray fully constrain the battery.
To change a battery the latch rotates and disengages from the round standoff allowing the tray to rotate until it hard stops against the frame tube. Once in this position, the connector can be accessed and unplugged. The battery can then slide over the lip of the tray and out of the robot, from between the tray and the belly pan(not pictured). The process is reversed to load a fresh battery.
Another cool feature of this mount is the way it ensures the connector stays plugged in throughout the match. After a few unfortunate mishaps in elims, our team usually zipties the connectors together for every elims match. In this design, as the battery is latched into position, the face of the battery slightly compresses the 6 AWG wire running from the lugs to the connector, against the two top standoffs. This creates a strain relief at the connector by effectively shortening the length of loose wire in this area so that the connector cannot be unplugged without first overcoming the small stiff section of wire behind it.
Lastly, special consideration was taken to mitigate the possibility of the latch coming loose during a match resulting in a dead robot. When the assembly is in the latched position, due to the geometry of the pivot points, the weight of the battery actually acts to force the latch further into the latched position. Furthermore, any forces pushing up from underneath the robot will do the same.
If this design gets built there will likely need to be multiple revisions to the latch geometry at the latch standoff interface to get the right amount of actuation resistance over the bump, since I just took a WAG at the right geometry.
Thoughts and feedback would be appreciated, thanks!