Tapping holes in 3" Flange Seals w. M3 tap?

I am wondering about the design intent behind the four (untapped) 2.6mm dia. holes on the inside of your tube flanges. They’re 0.157” deep. Has anyone tapped them with an M3 tap so they could serve as threaded fastening points for hardware inside the tubes? Would this conflict w/ other uses for these four holes? Are there other recommended ways to fasten hardware (PCBs) inside the tubes?

Hi @hsharpe, these holes are already M3 tapped on all of our flanges. We do use them to secure the electronics tray in the BlueROV2. You can see that here.


Thanks Jacob: That’s great! Didn’t have parts nearby: the CAD model just shows the hole as unthreaded. Appreciated!

Here you considered doing a 2" enclosure design with electronics tray for only a raspberry pi Zero and a camera module such as RPi v 2?

My application is for towing and I only need processor and camera. Do not need control, Rov or Lr Ethernet