I created this dust collector for my Bosch Router's 1617 fixed base. It fits a 1.25" hose connector to my dust collector and uses two M5 x 10 - 20 mm long screws/bolts to secure it to the router base.
The other dust collectors that I've found on ebay have narrow openings for the hose and don't collect as well or they use the lower two holes on the base which are not as secure. To fix that, I've opened up the end of the hose on the inside to be able to grab more of the dust and utilized the two M5 holes on the adapter for a more secure fit.

I've included the model for the fixed router 1617 base for any tinkerers out there that want to adapt to their hose diameter.

I recommend printing with 20-50% infill in PLA/ABS/ASA but it's entirely up to you.

https://www.printables.com/@AaronWood_741438/