Here's my Robbe smaragd, its about 30 years old and recently I have refitted some electronics. sailwinch replaced for the genua fore sail. it just did not function very well.
It sails like a beauty and very steady on coarse.

Trying to learn to use this forum properly I am publishing a video that shows an experiment I did to find out how fast the stepper motor could turn. I am using in my model of the sailboat Carina 2 stepper motors like the one shown in the video to work as a winch to control the position of the sails in a system solution where I am realizing this my own way to implement the sheets as shown on the original sailboat Endeavour. This requires my sheet control system to control the length of the sheet of the mainsail i.e. over a range of 8.3 meters. This requires the drum which is turned by the stepper motor to make 21 full turns. Details will be published in my report from scratch of building my Carina.