Electronics > Mechanical & Automation Engineering

copper braid/screen/shield dipped in solder bolted on star earth ground?

<< < (4/5) > >>

coppercone2:
ok doctor, you can believe whatever corporate bs you want

here is the manual picture, its a piece of braid with solder on the end that goes over a bolt


--- End quote ---


why would I make this shit up? there is no hidden mechanism, there should be no 'mayonnaise' in the 'sandwich'

there is a green yellow ground wire in the RC1 connector that goes over the same bolt with a ring connector. there is a big dent in the braid where the other ring terminals were on top of

I don't see the outline of solder for any kind of hidden washer (if there was a washer, it should be clean with a little groove around where the cut hole is in the braid, there is none, just smushed flat solder and copper wire

coppercone2:
in fact, I looked inside of the hole sideways and I see that its been clearly put in a solder pot then punch pressed or something, you can see the embedded wires on the perimeter surface of the hole (like 'damascus' wire rope steel or something), I am not bringing a microscope into the workshop to try to photograph this. If you have one you can look at it with a loupe and its plainly visible. All the braids are terminated in the same way.

I am telling you it looks factory original and also improper

coppercone2:
and here is a ebay picture of another welder with the same thing
https://i.ebayimg.com/images/g/VwMAAOSwuWVikGqE/s-l1600.jpg
(lower right near the front of the unit)

as you can see there is no termination like a real ground strap has, which would look like
https://encrypted-tbn0.gstatic.com/shopping?q=tbn:ANd9GcQZnORxFs8wAJkc8FYQ0667PUfJThyjQ7nFyv8sEIAuKGNqpDCWbrHSP8eJNixuLvGvk2xKc6zaoj1NcbmMT8LQsGsUeEd0bATYiavf437T&usqp=CAE

mag_therm:
Braided copper grounding straps with solder tinned ends, drilled, have been around for 100+ years.
One example is automotive battery ground straps, commonly used up until the 1960's I recall.
Other examples I have seen are industrial and ship board use inside enclosures for RF and electrical grounding of panels, subchassis etc.
On navy ships the electronic racks used to be on rubber shockmounts, bypassed by these straps.

They are still commonly available, search "braided grounding strap"

Solder, as we know, has poor creep and fatigue properties.
Hovever I think soldered braid is bit like polyester fiberglass.
If the coppper braid % fill is much higher than the solder that wicked in, the properties will be more like copper.

Doctorandus_P:
I'm not saying they did not do it the way you wrote but I did assume you made a simple (and often correct) assumption.

Look at it this way:
If you control the amount of solder so it's not excessive and combine that with enough force to deform the tinned braid enough then the solder will create an air tight seal but it has no further room to creep to, so creep will not be a factor anymore.

So I'm on the same line as mag_therm. If there is enough copper in between, then the tin only fills the extra gaps.

It's true that tinning wires that are clamped is considered bad because of creep, but that does not mean that this creep will always occur with clamped wires.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version