This afternoon I made an alternative shoe. I wanted to redirect the airflow around the bit w/o adding skirting below.
I also wanted some transparency to make alignment w/ cross-hatches on my workpieces a little easier (when I don't need perfect alignment, but just want to know my project won't cut off the edge of the workpiece).
I picked-up a 12x24 piece of Lexan at Home Despot and cut a top and bottom, I also cut a new BB center.
I'm including a couple of pics. The first is actually my binder clip clamping board. This is a holdover from my previous CNC machine, it allows me to clamp thin materials at the edges using binder clips. The surface is 12"x12" (perfect for materials that come in square feet) and I use a 12" square piece of cardboard underneath the Lexan as a spoil board. The board is just a 12" square of plywood with a 1/8" or 3/16" or so lip all around.
Binder clip clamping works pretty well. The trouble is that thin material can lift, so you have to pay attention to design (add tabs or leave an onion skin).
My binder clamping board is mounted to the Shapeoko 3 table with double-sided tape. My cuts here were all through cuts, I don't have any precision pockets or anything to worry about here. So I used double-stick foam pads (1" squares) from McMaster. I use a layer of masking tape on the Shapeoko table and also the bottom of my binder clamping board, to make removal easier. I love my McMaster foam pads, $7.00 for qty. 250. I used six to hold my binder clip clamping board down, so it cost about seventeen cents.
So far I'm liking this new shoe quite a bit. My K2 router shoe (which I made) was a conventional up/down affair with a vinyl skirt. The skirt became problematic when cutting deeper than about 1/2". Yeah, I could make skirts of various lengths but I find this fixed-Z shoe more convenient.
If I had to find fault: (1) I should have left a slot at the front of my shoe to accommodate the bit, removal and replacement of the shoe would be easier. In all honesty, I've replaced the bit a couple of times w/ the shoe in place, though, so not a big enough deal for me to remake this. (2) I should have increased the cross-section (widen) for airflow in the center of the shoe. I'm getting plenty but more is always better. I was a little worried about removing too much material and keeping things sturdy.
I'll use this a while and update if I make any more changes.