Dust Shoe for Genmitsu CNC 3020 with 65mm Spindle

I made this dust shoe after upgrading my Genmitsu CNC 3020 to use a Makita RT0701 trim router. I never really liked how the Genmitsu dust shoe bristles would get crushed and pusshed into the endmill during deep cuts so I decided to make one that mounts the the Z frame.

I mounted a metal bar (cut from a $2 shelf support I had in the garage - anything that attracts magnets will work) to the Z frame and use magnets to position and hold the dust shoe in place. The shoe can be completely removed very easily when the spindle is raised out of the way.

During operation the area being worked can be seen easily through the top of the shoe. I cut a circular piece with a 30mm center hole (a little larger than my 1" surfacing bit) out of a clear plastic take-out container and fixed it in place with super glue.

The bar mounts to the Z axis where the endstops screw in. I never used the endstops, but if you do this will not work for you. Or at least you'll have to find some other place to mount it (maybe on the extrusions, but then there's some impact on X travel). 

I included the step file for those who want to remix/mod to fit their own application. As is, the uptube OD is 25mm (1"). If your hose is a different size you can make an adapter or modify the original model in CAD.

Hopefully assembly is obvious from the pics. 

Parts:

• 2x M4x20 screws
• 2x M4 nuts
• 6x 2x10 neodymium magnets
• Dust shoe brush, something like this cut to size. (I trimmed the bristles to around 15mm)
• 8x M3x4 screws for holding the brush in place (optional - my brush was a tight fit without them) 

Some notes:  

• ABS or PET should be used since the router blows pretty hot air on the shoe. 
• You will want to glue some sort of shield to the bottom side of the shoe to block the air blowing through the router or the shoe will not be as effective. A simple way would be to add a primitive to the model within the slicer, but then you wouldn't be able to view the work through the top of the shoe.
• Gluing the magnets in place is a bit fiddly. Until the glue sets (I used clear Gorilla glue) the magnets will want to escape their settings and join together in a nice stack. After a couple exciting attempts to outsmart the magnets, the method I succeeded with is to put glue in all the recesses first and then put 2 magnets in at time while sliding a wooden block down over them. After all magnets are in place, clamp the block until the glue is cured.

Happy making!

Special thanks to Pyro Fox over on GrabCAD for the excellent model of the Genmitsu CNC 3020!!   https://grabcad.com/library/sainsmart-genmitsu-3020-pro-max-cnc-router-1

** updated files to remove unnecessary parts