Failed Knobs, Working Fender Washers, and Cams
The first two pictures are some knob designs that kept failing for me.
The next two pictures are using various length 1/4-20 bolts, a fender washer, and an appropriate sized spacer. This system, or screwing your project down to the spoilboard, will almost always solve any interference issues with my dustfoot.
Here is a small cam hold down, magically holding itself down to be cut out. It was drawn by Mat Gatten on the Romaxx forum, modified by me from his drawing to change the eccentric offset to 1/16" to better fit my needs. Here is the VCarve file.
The next two are a cam design I found on the ShopBot forum. Very nice ones with aluminum hubs are sold by David Buchsbaum, the guy who experimented to come up with the design. He also made a .dxf drawing available. I modified his aluminum hub design to be a screw or bolt, just to see how they worked. They worked great, and when the ones I made wear out the bolt or screw hole, I will order some of his. The original forum post is here, and his website where he sells them is here.
The first picture is the bolt down version, that bolt to my aluminum plate, or into my t-track. Here is the Vcarve file. The second picture is the screw down version. I flattened out the side of this one with a file to try larger ranges of clamping, but the 1/16 inch in the original was fine. If you use this Vcarve file, the countersink hole is too deep and needs to be modified.
