Two improvements: 1. Put 4 or 6 disk springs 'under' the the knurled nut. This allows to fine-adjust the tension of the 'clamp' so that you still can adjust the dial without losing its position after letting it go. 2. It is difficult to adjust joint and slide with just one clamping. I joined the two clamps with a kind of two-sided-bolt (head in the middle) and two knurled nuts. Then I can adjust joint and slide separately.