The MH2 motors are equipped with a 16 mm square shaft, directly attached to the motor. This shaft generally fits into a rectangular tube, with a 16 mm square hole passing through the tube wall.
With the Coveo, it's different: the attachment (shaft, flange, or yoke) is free-pivoting. This means that when the cover exerts force, the support tube undergoes bending, unlike the MH2 where the force is simply vertical. The result? The tube can deform, and a simple 16 mm square shaft is not enough.
The solution? A more robust attachment! The above-ground Coveo comes with a U-flange, which is securely attached to the tube via 4 holes (threaded or with a reinforcement plate inside to tighten well with nuts). And to prevent any loosening, Nylstop nuts are recommended.