Grounding of the RJ45 Shielding Connectors to Reduce EMI

Carson Barry wrote:

There were a few suggestions for securing the connectors to the sockets that came from that:

  1. hot glue
  2. velcro
  3. 3D printed, snap-fit, collar

I lean towards the latter 2 because they don’t require a consumable+tool+time to reassemble, though the hot glue would, if applied correctly, be the strongest of the 3.

Hot glue is cheap, common, very secure, and also keeps dust out, so I would lean
towards it.

David Lang

should also consider Ethernet cables modded with signal drivers at both ends of the cable, tap voltage from mainboard

The idea behind using ethernet cables was that they are cheap and readily
available in different lengths (for people modifying the system), going to
special cables defeats this purpose and it would be better to switch to some
other connector.

David Lang

Well that’s fine if things are working but they are not 100%. Maslow hardware design pushes the distance one can send I2C signals too far. Period. That leads to data link errors. Signal l drivers would help, especially in this harsh environment. Adding them in-vivo on the cable ends retrofits to the existing mainboard. Any solution is better than nothing.

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Why do I have an image in my head of two M4s both anchored to the same board, routers whining, trying to push each other out of the ring…

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I thought it was just me having that dream, tbh. Should probably have Bar check the firmware for ghosts.

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The dream has M4’s “harmonically resonating” together, and the sound they make…it sounds better than chitty chitty bang bang. :heart_eyes:

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Here is a prototype idea (needs to be taped to seal, as there is a slot to slide it over the cable. I’ll make the model available once I fix the centering of the slot, which I messed up on this iteration.

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Super cool!


Here is the 3MF EthernetCover.3mf (31.7 KB)

and the onshape model

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Does this also act to secure the connection against vibration causing disconnects?

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I wouldn’t think so. it just surrounds the port and a few cm above to protect from dust mostly. I think I’ll probably add a strip of electrical tape along the side where the slot is and the top to really keep all the dust out.

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Has anybody tried the flat more flexible 1ft long CAT 6 jumpers? I work in a data center I and I just saw a box of them and thought they might be more tolerant of the motion/wigging. Before I ask about liberating some from work I was curious. I’ll have to wait for the current project to finish to find out if we have spares or if we use some other cables.

I’ve also already backed the 4.1 upgrade so any solution I need would be short lived but if it solves the problem for people who don’t want/need to upgrade otherwises for cheap it would be good to know.

I think the hot glue fix is cheap and effective as a temporary solution.

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If I owned a hot glue gun. Does it actually stop them from wiggling loose?

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Definitely. I’ve had mine hot glued the entire time, and I’ve had none of the issues associated with them getting gunked up and losing connection. Just need to put a decent sized ring of glue around the cord about 1/2 back from the end of the cord then plug it in quickly while the glue is still molten. Shouldn’t wiggle out at all under normal forces and vibrations, but you should still be able to remove it with a strong enough pull.

And you should be able to find a hot glue gun just about anywhere for a few bucks. They can actually come in really handy for a lot of quick fixes.

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