Making a waterproof USB 3 cable

Build
1

Hi guys,
I need to make a waterproof USB 3 cable with Blue Robotics penetrators on each side (optionally a subsea connector on one side).

I was thinking of using a 10 core PUR cable and solder on an usb C male PCB kit on the inside of side A, and a standard USB 3 on the inside of the enclosure on side B.

Side A:

Has anyone done this kind of custom cables before? Will it be problematic getting real USB 3 speeds?
Any input on cable choice?

Cable option:

Lapp Olflex Servo FD 798 CP 10 Core CY Control Cable 0.25 mm², 0.5 mm²

It would be nice to use the Fathom cable, but it is only 8 core.

Thanks!

2

I don’t know about long-term subsea use, and how it compares to the polyurethane jacket you’re considering, but L-Com sells high-flex USB-3.0 cables with a thermoplastic elastomer jacket:

http://www.l-com.com/usb-usb-30-high-flex-type-a-male-to-type-b-male-15m#

I bought some for this purpose (connecting an external camera through BR penetrators) and it seems pretty tough and flexible, but I haven’t pressure tested it to any substantial depth yet.

USB 3 has a bunch of shielded twisted pairs for tight electrical impedance control. If you’re going to need full USB 3 speed I’d expect you’ll run into problems if you don’t use real USB 3 cable, but I haven’t tried it. The shorter the better if it’s not properly constructed cable.

3

Maybe some usb 3.0 over ethernet adapters inside the device at each and and then just use the Fathom tether?

4

Hi Magnus

Did you ever find a good solution to this? We are looking for a solution for an external camera housing with USB 3.0 between the camera and electronics housing.

5

Did anyone find a solution?

6

Anyone find a workable solution?

7

Check out Blue Trail Engineering; Cobalt Connectors and Cables | Blue Trail Engineering
They can make USB connectors/cables. It’s a custom cable based on their 6pin

8

For this case i ended up with potting in a heavy duty USB 3 cable and resolder it. I did an extra shrink wrap on the outside. If BlueTrail makes USB 3 solutions now it is great. BlueTrail makes solid solutions, ive used loads of their products.

9

They do mention USB cables on their custom product page, although they don’t specify if it’s USB 2 or 3.

If @k-deboer is right that their USB offering is based on their 6 pin cable then likely it’s only USB 2 (although that may still be sufficient for many use-cases).

10

This is Damon from Blue Trail Engineering. @EliotBR is right, our cables and connectors will only work for USB2.

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11

Love your work!
Would USB3 be possible in the future. It would open up a lot of options for UHD machine vision cameras etc. Unfortunately USB2 will not work for our use cases.

12

Thanks, Magnus! Unfortunately it may be a long time before we offer USB3-compatible cables and connectors. The electrical requirements are much more stringent than USB2.

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I expect at some point there may be some kind of sealed USB-C connection for these use-cases, but in the meantime they’re likely best served by ethernet or fibre optic connections, or cables with permanent penetrations.

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