"The motor controllers sometimes
dropping/misinterpreting commands during heavy load was solved by a
number of different fixes. Firstly, I believe with the USB to TTL
converters the data lines are pulled up to 5v with a 4.7K resistor.
I added a second 4.7K resistor in parallel to Tx to give the
controller more of a chance against interference. I also added
various smoothing capacitors, and edited my serial port byte
transmit tool to restore the serial port settings graceefully on
exit. Oh - I also cut the cables from their default 1m to the 12cm
that I needed.. No more dropped commands.
"The wheels are better reinforced under the base to cope with
the added weight and I have also balanced it out more by adding a
0.5kg metal cage to the opposite side to the battery. The metal
cage houses a proper DC to DC adapter which takes about 7.5v-15v DC
and converts to a clean 12V output."