3D Printed Drill Stop Collar
If you need to drill several holes to exactly the same depth, these are pretty commonly used tools in the shops, you can also buy steel ones from online/shop.
Heres a link from McMaster Carr
Model on Autodesk Fusion 360
I made the model on autodesk fusion 360. The model is fairly simple, I made the hole for the set screw a bit smaller from the measurement from between two sides of the threads
Slicer
Use any slicer that works for your printer
in my case, I'm using a ultimaker printer, so I use cura to prepare the print file
Set Screws
I got my set screws from a assorted set from amazon, you can also get it from McMaster Carr.
The set screws from the set just say 1/8 dia, I assume its either 5-40 or 5-44.
The set screws should thread in with a bit of resistance when you first drive it in with a allen wrench.
Put It on the Drill Bit!
Slide it through the drill bit. If it is too tight, i suggest loosen the set screw, but it on a vice grip and run the drill bit in a drill until it slide easy
Files Available on Thingivers
gumroad: https://gum.co/kGSOO
thingerverse: https://www.thingiverse.com/thing:3269839