Hold down clamps for T-slots

[morsa]

Thanks, Walney Col. That's a great idea. They are called cam clamps, and you are right, they are very useful in jigs. There are commercial items (i.e. Cam Clamps - Rockler Woodworking Tools), but of course you can reuse clamps from discarded bikes. Even in these hold down clamps, you could use a cam clamp instead of the threaded knob.
I have a pair of these discarded cam clamps and I will try to find them an application.