there have been a variety of designs. learnt much from this system.
Not using the cranks anymore, worked out a much more simple system.
main problem with the cranks is collision, and since the cranks and tracks needed to be connected, it used too many gears, or chains/ sprockets.
The cranks in these videos, in the links below, still have a clockwise and counter clockwise force transferred to the connecting rods, via their sun/planet gearing, The cranks frame is balanced by the force placed on the tracks by the connecting rod followers.
(The tracks are also on a wheel that turn in the opposite direction of the crank, their are 4 cycles for each 360 degrees rotation of the track wheel)
It's the connecting rods-followers, placing their force onto the tracks that creates an imbalance, The cranks frame has no back-force.
one of the connecting rods pair, is moving outwards from the center, while the other connecting rod is at or near center.
The connecting rod moving away from center pushes against the track, if the track wheel turns ccw, the connecting rod follower pushes against that track with a ccw force, at the same time it also pushes the crank frame away in a cw direction (SCISSOR ACTION).
"Have tried a few lengths.
the short connecting rod which is the same length as the distance between the axles of the sun and planet gear, its follower will stay at the center position of that crank for 180 degrees of the cranks rotation, it just turns as if its just the crank frame itself.
The next 180 degree cycle, it rolls outwards away from center and back down.
The longer connecting rod is about 1.42 times longer than the shorter connecting rod.
It forms a 45 degree angle, if the track is vertical, and the connecting rod planet gear axle is either at the 9 o'clock or 3 o'clock position. the connecting rod follower would be at 12 o'clock.
The long cylindrical tube in the videos, supply's force to the cranks, they are torsion springs.
Both ends of the torsion springs come out the one side, the center output shaft is one end and the hollow cylinder shell connects the backside of the torsion spring, so both ends of the torsion spring can be utilized from just the one side.
These supply the clockwise and counterclockwise force needed for the system.
only showing a system that uses 1 torsion spring.
The inner system of the blue cylinder below the torsion tubes is not shown, "there's more to that system".
That system in this design re balances the differences in rotation of the cranks input gears.
same system can be utilized to use weighted levers without tracks.
video links below.
https://www.youtube.com/watch?v=HrYF1BDQsS0
https://www.youtube.com/watch?v=N0FGmeU9MUM
https://www.youtube.com/watch?v=gsSiqgugxBw
https://www.youtube.com/watch?v=MmFXTSKx42c