Build your own Underwater Drone with 3D Printed Parts -- Episode 576

How bad is the water leakage? How did it compare to sealing with O-rings or a gaskets?

I think the issue is that with FDM printing it tends to leak through the printed layers rather than at the joins.

I think you can use PET-G to improve the layer-to-layer bonding, but it is still problematic as soon as you increase the pressure with immersion.  

I don't have a 3D printer but I would tend to think that the leakage occurs at the joints more than through the layers. But if it occurs through the layers I would think that a layer of epoxy resin might fix it.

The water will definitely leak through any FDM 3d print, and we tested that extensively over 2 years or so.

The solution is to seal the electronics inside a plexi tube. We use 3d printed endcaps with orings on both sides of the tube, but (as you suggested) we pour epoxy into them. We've  developed such a design in which there're no 2 layers of 3d print next to each other which could pass through the high pressure water. 

Tested in our pressure tank up to 8.5 bars, so simulated 85 meters depth under water 

The water will definitely leak through any FDM 3d print, and we tested that extensively over 2 years or so.

The solution is to seal the electronics inside a plexi tube. We use 3d printed endcaps with orings on both sides of the tube, but (as you suggested) we pour epoxy into them. We've  developed such a design in which there're no 2 layers of 3d print next to each other which could pass through the high pressure water. 

Tested in our pressure tank up to 8.5 bars, so simulated 85 meters depth under water 

Was it difficult to seal the cables? How in general did you do it? I slowed down the video to watch disassembling the end-cap from the plexi tube but couldn't see the details. Very good video btw.