Here is my solution for a quick advance hold down. I use 1/2 of a pipe clamp mounted on a short 3/4" pipe in the hardie hole. The shaft collar keeps it from sliding down and there is a pipe nut on the bottom side to keep it in place. Works fast. https://www.flickr.com/photos/21275592@N04/sets/72157642602601563/ James Binnion jbin at well.com