bloomberg
Posts: 7
Joined: Thu Jun 13, 2013 5:32 pm

Wanted: RPI cable strain release case

Sun Aug 04, 2013 9:54 am

Hi,

I will be installing about 10 television screens with RPI's attached. during a small festival. The screens will show a basic slideshow with the sponsors, timetable and such things, nothing fancy.

I've done this before, with the RPI's in a default black plastic case, which is sturdy enough for the use. The only problem I have is with the cables: they are far too easy too unplug. Even accidentally if somebody is messing with the cables of the taps or something like that.

So I'm looking for a case which you have to open to unplug a cable (with some kind of cable guard...?) and with some built-in strain release, so if a cable gets pulled the connector on the RPI doesn't break off. I also hate the SD-card sticking out. (I know you can buy these special smaller adapters, but I would just like a bigger case.

I know you can buy these short cable extenders to use as port savers, but I don't really like this, as this is another point where the connection can get broken.

Does anybody know if something like this exists? Commercially?

Proto Armour seems the best I've found, but they don't have some kind of strain release.

Something like 'the spin' (http://www.buildingthespin.com/). But this isn't commercially available yet. And It doesn't have to be round, or good looking at all.

So, any ideas?

GordonTGopher
Posts: 70
Joined: Sat Dec 01, 2012 11:25 am
Location: Letchworth Garden City

Re: Wanted: RPI cable strain release case

Sun Aug 04, 2013 10:36 am

Not really what you are looking for but using a case with a VESA mount and using cable ties to secure the cables onto the mount might be better than nothing.

Gordon,

mrlinux2u
Posts: 213
Joined: Sat Sep 24, 2011 8:38 pm

Re: Wanted: RPI cable strain release case

Sun Aug 04, 2013 11:44 am

I've got the VESA-Pi case going on sale at modmypi in the next few weeks, although it doesn't have a cable strain, it does protect the sd-card from damage - see the attached pics and see what you think. As you can see the HDMI port points down so not to place too much strain on it.

If necessary I can modify the design to your requirements.

Cheers

Paul
Attachments
vesa-pi-stage-2.jpg
vesa-pi-stage-2.jpg (29.47 KiB) Viewed 2523 times
vesa-pi-stage-4.jpg
vesa-pi-stage-4.jpg (25.31 KiB) Viewed 2523 times

bloomberg
Posts: 7
Joined: Thu Jun 13, 2013 5:32 pm

Re: Wanted: RPI cable strain release case

Sun Aug 04, 2013 12:38 pm

I'm not using a 'real' VESA mount, but I've secured the RPI to one of the VESA threads. Works good enough for stability.

A bit more information to what I'm actually searching for:

The only problems I've had so far are the following:
People stealing the SD-card.
People (bar personnel or other crew members) see an SD card sticking out and it is far too easy to pull it out and slip it in their pocket. So an 'open' design like the above mentioned VESA mount is not an option. I know you can still open a closed case and steal the SD-card, but this is far less likely to happen. I'm not really worried about the sd-card 'breaking off'.
Cables unplugging
In the setup I'm using I just use the HDMI and the Power connector. To connect the HDMI to the television I use short cables going to the television which are not in the way of anything, but the power connector usually goes to the ground where the power sockets are installed. But the ground is full of cables and hoses that it's possible to simply unplug the RPI when moving some of the cables. The micro-usb connection isn't a really strong connection.

uUSB socket breaking
Also, in addition to the above, I've had a few uUSB sockets breaking off because somebody pulled the cable (accidently or not?).

These are the reasons why I'm looking for an enclosure which encloses everything (and not just the board itself), and has some kind of strain release.
The 'The Spin' case looks good, but will probably be too expensive for what I want. It doesn't have to be round (rectangular would work too, or made of aluminium. I noticed there is a lot of wasted space inside the 'The Spin' due to it's roundness, and I would love to keep it as small as possible given the requirements.

To conquer these cable-problems the last time, I indeed used cable-ties and some gaffa to provide some external strain-release, but this just looks hacked-together and will take some time everytime I want to change anything in the cable setup. I would rather have some kind of all-in-one enclosure to take care of this, to make the installation a lot easier and quicker.

thanks ahead for your replies.

edit: that VESA mount does look good. Might consider that one to mount onto my television at home.

mrlinux2u
Posts: 213
Joined: Sat Sep 24, 2011 8:38 pm

Re: Wanted: RPI cable strain release case

Sun Aug 04, 2013 1:44 pm

@bloomberg

Glad you like the VESA-Pi, I've also got a case that blocks the sd-card and micro-usb inside the confines of the case and as mentioned I could modify the VESA-Pi to suit your requirements (wouldn't take much).

You could also use a micro-usb extension cable - route that to the bottom of the case (with the aid of some guides in the case), that way if someone pulls the plug, there's little or no strain on the micro-usb connector.

If you want to discuss it more, just PM me or email @ paulks@kersey-smith.com.

Cheers

Paul


ame
Posts: 3172
Joined: Sat Aug 18, 2012 1:21 am
Location: Korea

Re: Wanted: RPI cable strain release case

Thu Aug 08, 2013 11:52 pm

Cyntech also have a VESA mount for their Pi case, and an SD Card cover to make pilfering more difficult.

http://shop.cyntech.co.uk/collections/all

gdt
Posts: 85
Joined: Thu Jul 19, 2012 10:19 am

Re: Wanted: RPI cable strain release case

Fri Aug 16, 2013 2:31 am

Why not use a standard ABS enclosure, mount the RPi using nylon screws through the test/mounting holes, and feed the cabling into the box via typical nylon grommets (you can get "split" grommets which allow you to pass through the connectors) or via through-connectors (USB-USB and HDMI-HDMI through-connectors are cheap enough).

If the environment is that hostile, I'd put the power supply in the same box. If they're going to knock off a SD card they'll also knock off a phone charger. With the power supply in the same box you could use a typical 5V power supply and connect to the PCB pins. You'd then run in the 230VAC cable through a stress-relief + retaining grommet, and onto the power supply input terminals. You cut, strip, tin, crimp a terminal connector, and heat shrink the wires so that there is no swarf carrying high voltages. Convention is that the earth wire is cut twice as long as any other, so that it disconnects last. It's also convention that the cable is held twice (say once by the grommet and then once by a clamp, and you place those at angles to each other, to minimise slippage if someone yanks the cable). You lay out the interior so that a loose power wire can't reach anything other than the power supply. If the power supply doesn't include a fuse then you provide one on the Active, with a rating to match the power supply's inrush current (the maximum current you get when turning on the power supply with a load attached).

In a hostile environment I'd also be inclined to use grommets rather than through connectors. Although the result is less flexible it doesn't offer the opportunity for someone to score a HDMI cable. If you need connectors, then think about placing a peg nearby (or just a pair of holes in the box if you don't need to worry about water). Then you can cable tie the cable to the peg, slowing theft of the cable.

Another worthwhile trick is it mount the gear high. So if you have the screen on a pole, the gear mounts to the pole above the screen, not below it (as you often see). Use a loose black cotton bag to hide the mess.

Using correct-length cables also deters theft. People don't want a 0.2m HDMI cable.

One of the things you'll discover is that the "mechanical engineering" of bespoke projects can get expensive rather quickly. Some shopping around can make a big difference. Not only for cost, but for modular components (ie, the power supply might include fusing and a cable retainer).

In the events rigging trade its usually done to do a messier job but to hide the results; for example, to gaffer tape your device rather than use a mount, then cover it with black cloth. That has the advantage of expensive equipment not being in plain sight.

Return to “Other projects”