Tether entry sealing

General Discussion
1

I’m currently working on a small ROV for a research project - quite new to ocean robotics here. The tether for this is a flexible polyethylene tube - the ROV will only be used in test tanks so it does not need to dive far or for very long. The tether will enter the ROV through a hole in the outer hull (preferably a permanent connection), then the cords inside the tube will enter a pressure vessel inside the hull with a WetLink penetrator.

The hull piece is 3D printed with several coats of polyurethane applied afterward, and is already tested to be waterproof. How can I allow the tether to enter the outer hull while keeping the hull watertight (e.g. using some kind of mounting piece like a pipe flange, sealant, etc.)?

2

Hi @Runaways0310 -
A WetLink penetrator of the correct size should work for sealing your tube, assuming it isn’t too flexible! Since it isn’t a cable, you may have to drill out the cable “step” internally to get the tube to fit thru - this reduces the depth rating but if you’re only in a tank that shouldn’t be an issue? Checkout the guides on the product page for more help!
Generally, I wouldn’t trust any 3D printed hull to remain waterproof indefinitely, even if epoxy coated…