I work at The Mill
, a makerspace in Minneapolis, MN. We've got a shopbot and it's a fantastic machine.
The original dust skirt on our ShopBot took one too many hits and frankly I wasn't a big fan of the design. This one is built using some scrap 3/8" polycarbonate, a 2" #8 bolt and nuts, and 16 3/8" x 1/4" cylindrical rare earth magnets.
There are 2 pieces to the design.
The first is the main shoe that clamps onto our spindle.
The second piece is used as the spacers as well as the dust skirt. You can create as many spacers as you need for the length of bits you use. I made 2 to start.
This system makes it extremely easy to remove the skirt for bit changes, z-zeroing, or operating without the hood altogether. It stays out of the way of the Y gantry when the z axis needs to be raised. It also eliminates the need for that silly thumbscrew that held on the factory dust hood. You could rarely get to it when you needed to and it was located in a potential pinch point.
I've included the DXF files so you can take this to any cad/cam combo you like.