Hey, all. I’ve been having problems with my BlueROV2 where every few days one of the thruster penetrators will twist lose due to the torque of the thruster cable, requiring us to remove the housing and re-tighten. We’ve been screwing them in finger tight, and then using the tool to go a quarter turn beyond that. It’s not isolated to one penetrator, but has been an issue with three of them so far.
Either, is there something we are doing wrong here, or is there a solution to reducing the torque or maintaining tightness?
Have you considered using a thread locker, like some type of Loctite? It’ll prevent the penetrator from coming loose, but will still let you easily remove it without needing too much torque.
I’m curious why you have torque occurring on the thruster cable? In our BlueROV2 assembly guide the penetrators get installed first, so the thrusters can be rotated to have minimal cable torque before mounting.
Tighten to finger tight, then use the provided wrench to tighten them an additional ~1/16 of a turn. If you can’t loosen them with your fingers, they are tight enough.
If you can’t loosen a penetrator with your fingers but it’s coming out on its own then the cable torque and/or storage/transport vibrations of your ROV must be quite significant.
This isn’t a bad idea but make sure to keep it away from the thruster casings and propellers, as many thread-lockers will cause polycarbonate to become brittle, which can cause cracks or fractures.