about this point "5/ Overall I feel this gear area very open. There is still a way to enclose it later for safety/aesthetic, but you could also use this enclose to built a gearbox : this can be laser-cut, which will facilitate adjustment, as drilling will be precise enough so you will probably not need it."
Just as a reminder, i dont know if you remember that on the last call, i mentioned that keeping the safety components in mind while designing the mechanical components was key to make sure everything would be intergrated nicely and also as a consequence this could give a function to this part, other than "just covering" (if you would consider it as part of the system), like in this case, holding the bearings and the axis and making the adjustment easier. (edited)
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