Update 30 Aug 2018: Uploaded STEP file containing the 3 router parts.
This dust shoe uses the included black adjustment ring from the DeWalt 611 router to control the height of the shoe brush and act as a quick release for easy tool changes. (The ring is normally used to control bit depth when using it as a handheld router.)
Adjustable brush height
Integrated lever clamp to firmly hold the brush at desired height
Quick release clips for tool changes
Vacuum port can be positioned on any of the three sides of the Shapeoko 3 router mount
I used the following brush strip from McMaster and bent it into the ring channel on the underside of the base piece. Thanks to Mhuff for the idea to use the brush strip.
Bending the stainless brush strip can be a little difficult, McMaster has other types of brush strip that may be easier to use, but I haven't tried them.
Supports are only needed for the largest piece.
Be sure and break out the supports created inside of the vacuum port.
Fun fact, if you're lazy like me, a broken chopstick can sometimes be used in-place of the 3D printed lever pin.