I've never felt happy after changing the upper slot limit switches,people kept reporting strange behaviour such as opening in wrong order or only opening partially so after the latest series of malfunctions its time to fettle it.
Two new upper limit switches fitted and more care taken with the clearances to the actuating cams and then we adjusted the lower switches so the lower shutter now stops when fully open.
It now preforms as intended, its 8 years since we built it so there's bound to be a bit of wear and tear and apart from paint wearing off the rotation sensor its been reasonably problem free, lets hope it carries on to be so.
Dave