R is crank radius (in yellow)
L is length of conrod (in green).
L is a little larger than R: L = 1.0125R
If the crank is driving, the mechanism is hard to move because of large pressure angle (between the conrod and moving direction of the slider).
To fix this problem here the mechanism is added with two gears to make the conrod driving.
Pink gear of tooth number Z1 is the input.
Green gear of tooth number Z2 is fixed to the conrod.
Here K = Z1/Z2 = 1
A working cycle (W) corresponds 2 revolutions of the pink gear.
The crank rotates irregularly.
Advantage: orange slider rests at its right position rather long, around 0.2W.
For other value of K, W will be changed.
It is possible to use chain drive instead of the two gears in case the crank radius is too long.
The mechanism needs to be verified in practice.