This thread recounts how I resolved the torqueing problems that I was experiencing with the Toyo 810MII. Note that all problems were not completely resolved until I exchanged the Arca Swiss hex screw for one with one more turn of bite:

https://www.largeformatphotography.i...or-Toyo-810MII

Mounting the camera onto the head is done by sight: You simply open the Arca head and slide the camera onto the head by sight keeping the overflow of the plate even on both ends. No guess work as with the Manfrotto QR system.

Thomas