Ya don't need any of those contraptions, I've tried them all. Spring clamp on the top & your thumb in the middle, I have never had one move or slip.....EVER! View attachment 131184
Which I also used for years... and then I tried using the Irwin clamp and experienced just how much more solid the connection between the file and the guide was and how much easier it was to use the tool with precision. Just trying to help out a few folks with a better way. Trust me that it is better...