How to cut/splice a USB3 cable for outdoor webcam project?


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jebus197

Hi I am doing a small project to build my own outdoor web cam to watch some local wildlife in my garden. I could buy an expensive camera just to do this, but I already have a pretty good Logitech Web cam that can do 4K that I don't use, I also have a fair collection of simple plastic type waterproof project boxes, clear perspex and as the camera can get quite hot and as the weather can get hot in the summer too, I figured I might as well stick a fan in there too. Both the camera and the fan are connected to a simple 4 port USB 3.0 hub, but now I need to run a USB extension cable inside the box. (Like this one: https://amzn.to/2J3MbRX). However if I want it to be watertight, I need to make the hole as small as possible (which I will of course seal further with a standard cable gland (https://amzn.to/2JeidtZ)  and silicone sealant). So I need to cut the USB 3.0 extension cable and rejoin it. But here's where it gets kinda tricky, as although I probably did something similar maybe 20 years ago by joining 2 USB 2.0 cables together, the whole arrangement seemed a whole lot simpler.

 

With this cable you have to get through (what I assume is) two separate layers of shielding first, then there are a total of 4 internal unshielded wires (red, green, black white) then two separate sets of additionally shielded wires, each containing two wires each, so one set contains blue, yellow and the second set contains purple and orange. What I would like to know is this just a straightforward  cut and splice job, with each colour corresponding to the same colour on the spliced part of the cable? I mean, I sure logically it is, but what concerns me is why is there so much shielding and do I need somehow to try to conserve this and to not just cut it away and discard it?

 

As I said, it's been years since I attempted to do anything like this. I looked for YouTube videos, but they all talk about USB 2.0 and don't talk much about the extra wires, or the shielding.

 

Any assistance would be appreciated.

 

Thanks.

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jebus197
8 minutes ago, Som said:

everyone is on the trump biden forum and can't get out.

 

rather than cutting cable why not try something like this

https://www.screwfix.ie/p/mk-pvc-cable-entry-grommet-20mm/84115?gclid=CjwKCAiA5IL-BRAzEiwA0lcWYv_6giwKPaVg6orHJYOaW2MlmP6m370AaF4Kc-CEMsbUZe-WAh6I2BoCUygQAvD_BwE&gclsrc=aw.ds

That's a half decent idea. Thanks. It would work in this usage case?

 

Just for the record though, is there a resource anywhere showing how to join these cables correctly?

 

I mean I have looked, but everything I have found is for USB 2.0.

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goretsky

Hello,

 

Why not just cut a rectangular port for the USB 3.0 extension cable into the waterproof project box, seal it with epoxy, plug the cable in, and apply waterproofing to that connection?

 

Regards,

 

Aryeh Goretsky

 

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Som
On 27/11/2020 at 13:28, jebus197 said:

That's a half decent idea. Thanks. It would work in this usage case?

 

Just for the record though, is there a resource anywhere showing how to join these cables correctly?

 

I mean I have looked, but everything I have found is for USB 2.0.

should be fine, as long as it's water tight. I've never had the enthusiasm to wire usb cables so i don't know, i would presume the technique is the same as usb 2 though. 

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jebus197
On 28/11/2020 at 09:58, goretsky said:

Hello,

 

Why not just cut a rectangular port for the USB 3.0 extension cable into the waterproof project box, seal it with epoxy, plug the cable in, and apply waterproofing to that connection?

 

Regards,

 

Aryeh Goretsky

 

Thanks guys. You are both stars. Aryeh is a true star though. Sometimes I think he and a few other old timers here (Sam included) are the only thing that still keeps Neowin going.

 

I'll give both your suggestions a go probably - and I have already bought some rectangular USB grommets as Sam suggested. Still, if anyone wants to chip in on how to cut/splice a USB 3.0 cable correctly, I'm all ears. Just for reference of course.

 

But seriously. Thanks guys!

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jebus197

Whelp, here's my take on this. Not worth the trouble! If you have 9 wires to solder/join and you happen to screw just one of them up, or the contact isn't perfect, you could spend hours cutting and splicing and testing and trying to find the one that isn't any good. It turns out too that all that 'insulation' probably does play an important role too and that a USB 3.0 cable is quite a well engineered thing. Nothing like the simplicity of the 4 wires of a USB 2.0 cable.

 

So scrub that for a plan.

 

Instead I'm going to go with this, with the USB port obviously pointing inside the box rather than outside. All I have to do then is make a hole big enough for it.

 

https://amzn.to/3g2Wlhx

 

This will plug into a spare USB 3.0 hub I have inside my project box and given it comes with rubber sealing grommets, it should provide decent protection from the elements.

 

But hopefully that's it.

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Astra.Xtreme

Something like this would be easy, as opposed to doing a solder splice:

https://www.amazon.com/Terminal-Connector-terminals-Pluggable-Converter/dp/B07JN11SKT

 

Or you might be able to find a cable grip that will fit the USB head and still have a good seal around the cord.  I designed a few products that use an RJ45 Ethernet cable running into a NEMA 4X enclosure, and the cable grip fits the RJ45 head and gives a good seal.

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jebus197
37 minutes ago, Astra.Xtreme said:

Something like this would be easy, as opposed to doing a solder splice:

https://www.amazon.com/Terminal-Connector-terminals-Pluggable-Converter/dp/B07JN11SKT

 

Or you might be able to find a cable grip that will fit the USB head and still have a good seal around the cord.  I designed a few products that use an RJ45 Ethernet cable running into a NEMA 4X enclosure, and the cable grip fits the RJ45 head and gives a good seal.

Only thing is those terminal blocks are for USB 2.0. Looking around, there seems to be very little/none that I can find for USB 3.0. (I guess there must be a reason for this). It does need to be USB 3 I think. First, due to the required length of the cable ~4m (without repeaters) and because the web cam is quite a top of the range 4K Logitech model. (Which unfortunately, despite this, I've never really found any other much meaningful use for. So I might as well make it a nice all weather web cam to film the wildlife in my garden.). So, as it's 4K, data throughput is important - and the camera itself has a USB 3.0 connection.

 

Care to elaborate on exactly what you purchased Astra? I already bought the parts I listed, but future reference might be helpful.

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Astra.Xtreme
34 minutes ago, jebus197 said:

Only thing is those terminal blocks are for USB 2.0. Looking around, there seems to be very little/none that I can find for USB 3.0. (I guess there must be a reason for this). It does need to be USB 3 I think. First, due to the required length of the cable ~4m (without repeaters) and because the web cam is quite a top of the range 4K Logitech model. (Which unfortunately, despite this, I've never really found any other much meaningful use for. So I might as well make it a nice all weather web cam to film the wildlife in my garden.). So, as it's 4K, data throughput is important - and the camera itself has a USB 3.0 connection.

 

Care to elaborate on exactly what you purchased Astra? I already bought the parts I listed, but future reference might be helpful.

You're right, I'm not seeing any USB3 ones on Amazon.  If you're adventurous, there are some random sites that seem to carry some:

https://www.reichelt.com/de/en/usb-3-0-a-socket-10-pin-terminal-block-delock-65370-p127469.html?r=1

https://www.gravitech.us/usb30tyfebrb.html

 

Here's the glad I use for an RJ45 cable:

https://www.alliedelec.com/product/l-com/asr-pg16/71575197/

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jebus197

Also just to complete this, if anyone is ever looking to build a project of any kind using a project box, you will need a hole cutting drill bit like this: https://amzn.to/36EfVxA

 

The advantage of my box is I can fit and change a range of sensors in the box too, so long as they are all USB enabled. So the choice is quite wide.

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