We further gave thought to your point about ‘problem of dismantling of motor & gearbox’ while maintenance work.   We have imagined a devit arm system wherein it will be easy for you to shift the gearbox-motor and open the roller chain coupling.   We have primarily  thought of 2 design options and requesting you to review and see which is your preferred choice.   Based on your choice we will firm up the design.   [Sorry to bother you on the topic of coupling again.  Increase in height of the top assembly due to the use of rigid coupling (771mm) & heavy weight of the coupling itself (almost 275 kgs) asking us to request you once again for a review.  Refer the 2 comparative arrangements of the coupling system already submitted.  If your choice is still rigid coupling, do let us know.]                               