This weekend after some further digging into circuits and motors, I wanted to see if anything in the wiring of the box mag was causing the motors commutators to burn up, which is how all the motors had failed.
After some reading I discovered that the 8.4v going to a ~3v motor is not great for the commutators, which will likely lead to sparking and overheating/melting of the commutators. So I set out to learn how to resolve this, and a few articles and handy online calculators later I have some resistors in the mail to modify the wiring per the below diagram I put together. Will post again once rewired to show how that looks and results. All the calculations were done using a fully charged 7.4v lipo (8.4 volts), a maximum motor draw of 2.2 amps at motor start up, and a motor input voltage of 2.4-3.0 volts. In other words its designed using the highest load, even though the motor amp draw will likely drop once the motor is turning.
The following handy Voltage Divider calculator from Digikey was used to determine the resistor values, and can be adjusted with an input voltage of 12.6v for an 11.1v lipo at full charge.
https://www.digikey.ca/en/resources/...oltage-divider
The following Voltage Drop calculator was used to determine wattage rating for the resistors and will need to be used as well for an 11.1v lipo. The motors I'm using have a max draw of 2.2 amps for reference.
https://elecurls.tripod.com/drop-res.htm
In the below diagram, the following resistors are used:
https://www.digikey.ca/en/products/d...-5R60J/2564360
https://www.digikey.ca/en/products/d...-10R0F/2360935
