Have a sigma 8mm / 3.5 and a lens ring for R1 for it.
outer metal ring: LR2
However when i mount it and tighten it up very sturdy the sigma can still rotate. Especially when using the camera the lens ring turns easily.
Now i noticed there is some space between the sigma and the lens ring, light is shining through. I made a picture. It is not fitting well and i can not tighten the knob more without damaging the lens. I am almost sure i did the mounting according to your specification.
I have another lens ring for nikon 10.5 and that one fits perfect. Very sturdy.
In the lens ring component matrix the dimension of the outer metal ring LR2 should be : 83mm. When i measure the inside of the ring it is 76 mm. That is the dimension of the LR3.
So... someone knows what to do. Can i have by accident a LR3 outer ring instead of LR2??