This video is an attempt to decode the mechanism shown at
/watch?v=SKgb-6vf4pc
Brown step motor is for bending motion.
Bending motion is transmitted to orange bending plate via Oldham mechanism of blue cross groove disk.
Violet step motor is for controlling yellow pins.
The rollers are pivoted on the bending plate and supported by orange bridge.
The bending plate can rotate around one of the two yellow pins (around the pin that is inserted in the hole of one green roller).
The violet motor of grey oblique disk ensures that when one yellow pin is in the hole of one green roller, the other pin is not.
So the bending plate alternately rotates around two yellow pins.
Device for advancing tube after each bending is not shown.