Hi, our team has been complaining about the unreliability of shaft collars. We are wondering how other teams deal with this. In our testing, we noticed that no matter how tightly we tighten the shaft collars, they begin to slide on the shaft gradually, and after a few days of testing, they cause our lift to be at an angle, as the c-channels we connected by shaft colllars have slid. The shaft collar screws don’t have a good grip, strip easily, and are overall low quality. How do other teams deal with this? Would you recommend using Rubber/Clamping shaft collars instead? Also, I have heard mentions of “high-strength shaft collars” on the Vex forum, but I can’t find them on the Vex store. Do those exist?
The set screws you use to tighten the lock collars have little cups in their ends. Any set screw will eventually end up with flattened cups, which behave as you describe. Take a look at ALL your setscrews and throw out the ones that are flat. Then, replace them with better ones. I’ve used these for years: 18-8 Stainless Steel Cup-Point Set Screw 8-32 Thread, 3/16" Long (https://www.mcmaster.com/#92311a189/=1alkz0y). The cost is $4.51 for 100 screws.
We do what Rick said. Also, for explanation: “High Strength Shaft Collars” are for High Strength shaft, which is 1/4" square instead of 1/8" square. Here is the VEX Robotics page for HS shaft: https://www.vexrobotics.com/hs-hardware.html
A high strength lock bar (keeps you from stripping or breaking HS Gears) is also available from Robosource.net VEX only makes regular lock bars.