Review on Efficient and Versatile - POWERTEC 71164 Cam Clamp 20 for Reliable Holding Power by Darion Wooten

These were designed to replace knobs to hold things in place along a T-rail (corner rail in my case). Upward tension is created by leverage/cam action. I like her but I have a few complaints. First, I wish I had a 5/16 inch version. The metal/rubber washers don't provide a very stable surface for the lever. The narrow 1/4" screws allow for too much tilt and play. Second, the system is very sensitive between being too loose and too tight. Sometimes there's a lever in that sweet spot that's pointing at my fence and I can't close it. Thicker rubber can offer more stability or maybe less cam action. Sweet spot extra easy to close. I tried adding lube to the metal washer, which helped a bit. I'll try a nylon washer to see if it improves performance/reduces friction.