Here is a part I machined today to hold a clear 2.5" dust tube for my Shapeoko 3 XXL with a 3.2 HDZ. I have a Dewalt 611 router and a dust boot I bought off etsy. So this was originally the inspiration of Jon Eckels for a Z-Plus with Sweepy Dust Shoe. I had an earlier piece made that fit over the Z stepper motor and held the flexible 2.5" dust hole. I made mine out of popular because of weight concerns. I recycled some of Jon Eckels elements.
Since this is for a 3.2 HDZ I do not know if the dimensions of the bolts that I used to secure the piece have changed.
The mounting holes were 4.5" center to center for the outside holes, 2.430" center to center for he inside holes. I made mine with all four mounting holes because the weight and the extension of the piece I was wanting to make sure it was held securely in place.
Here is the Carbide Create file in V7 (710). Unfortunately this file will not work with V6 or lower due to the change in c2d file format.
hdz3_2_SO3_dust_holder_v7.c2d (364 KB)
The Dewalt router and my 3rd party dust shoe had the center of the 2.5" tube at 6" from the rear. The center of the router was 2.0" from the rear. If you have a Makita/C3D router you may have to adjust the router hole. The center will be still be 2.0 for a stock Shapeoko Router Mount but the diameter of the hole might be slightly larger.
The piece was mounted upside down over the screws I had inserted into the HDZ bearing mounting holes. The bolts were 5MM .07 Thread and were 22MM long. I inserted the bolts with washers partially in the mount and placed the plate over the screws and pushed the plate down and tightened up the bolts.