This is a tab for mounting 3mm glass to a 3D printer - four of these will be required, one for each corner. The holes are 3mm diameter, and designed for M3 bolts.
The 3mm glass plus the PCB will add up to a height greater than the 3mm allowed for in the 'void' in this model - the idea is that this will create a bit of a press fit with the glass, and hopefully the glass won't be able to move around when the tabs are tightened. This should also mean that the tabs don't need to line up perfectly with the corners of the glass in order for the glass to be held tightly in place, ie. the mounting of the tabs doesn't need to be perfect. Another way to achieve this friction with the glass would be to add some higher friction material to the void space, in between the glass and the tab.
I've now added a *.stl file of the tab
Modify this model to account for the thickness of the glass you're using - ie. 3mm void height for 3mm thick glass. Once printed, the holes may need to be drilled out with a 3mm drill bit, to ensure bolts can fit.
Place glass on the wood it is to be mounted to, and draw an outline in pencil where you'd like it to go. Place a mounting tab on one corner, so that the corner of the void space under the tab is a few millimeters back from the corner of the glass (corner of tab does not need to touch corner of glass).
With the tab in place on the wood, drill through the holes again, going all the way through the wood. This should ensure that the holes in the tab line up with the holes in the wood. If you need to secure the tab to the wood with a small clamp for this, go for it.
Repeat for the remaining 3 corners/tabs. Use M3 bolts to secure the tabs down, making sure the glass is in place for the final two tabs (or you won't be able to get the glass in!).
Feedback is appreciated on whether or not the space left under the tabs for the height of the glass is too much/too little, and whether the glass is held securely or not.