The printer I used for the frame sections had an issue that I have now resolved. I reprinted those parts and also made the dual ring gear, or hybrid ring gear, a little stronger so it is less prone to deforming under load. I also found two bad pivot bearings and replaced them.
As tested:
28 bearings
17 gears
Blue motor alone: 0.07 A
1:1 direct head-to-head, 1 Blue driving 3 Yellow:
0.48–0.50 A
2:1 system, no load motors:
0.16–0.23 A
1:1 system, no load motors:
0.18–0.24 A
2:1 head-to-head through the system, 1 Blue driving 3 Yellow:
0.45–0.54 A
All tests were run at the same 6 V power-supply setting and allowed to run until reasonably stable.
These are the measured numbers from this build. They are not being presented as evidence of gain; they are simply the results from the current configuration.