# please sanity check my idea transmission line going through sliprings)

#### Lundwall_Paul

Joined Oct 18, 2011
226
I know in modern day Radar systems that slip rings were eliminated by using a cable wrap system. This allows the antenna to swing +/- 400 degrees.

#### THE_RB

Joined Feb 11, 2008
5,438
Since they said "never clean the ring" the ring surface must be known as finicky. I'm guessing they have become damaged/corroded etc over time, or maybe just that the cleaning itself has removed the patina so now they are damaged.

From my perspective if the dry brushes and rings are giving problems then I would try a lube maybe just on a test area if it's possible to monitor just one area (one machine? one section of the machine?). The lube should at least catch dry particles and allow them to be pushed out from under the brushes. The other crew that used an abrasive cleaner probably left a ton of particles on there.

The lube should also stop dry corrosion problems if that is occuring (which is likely).

#### shortbus

Joined Sep 30, 2009
7,670
there's no link in your post, but I think you are on to something there with the spring tension again. Every time the brushes are cleaned, they are pulled back to insert a cloth or whatever between the brush and the ring. this could explain why the problem happens exponentially more often. more failures leads to more cleaning which stretches the springs, which leads to more failures. I am going to see about getting new springs.

Some guys are not to easy on equipment while working on it. Especially if its a pain in the a type thing.

#### strantor

Joined Oct 3, 2010
5,226
Ok, I've finally gotten a response from the manufacturer. they mentioned nothing about brush maintenance, but instead sent me a link and suggested I install these. I take that to mean that they have probably had other complaints are now installing these themselves.
No specific instructions on how it should be done, but this is what I'm thinking (last image):

some excerpts from the manual:
The PRB (Power Rail Booster) is intended for use as a network component in
electrical PROFIBUS networks. It's purpose is the amplification and safe, reliable
transmission of PROFIBUS signals. The PRB enables the transmission of
PROFIBUS signals over contact rails, loops and other cable types (such as
telephone cables) not compliant with the PROFIBUS Specification. The PRB also
enables data transmission in the face of an excessive EMC load.
...
The PRB can be easily integrated in existing PROFIBUS fieldbus networks. It is also
possible to configure a complete PROFIBUS fieldbus network in line and/or star
topology. Except for the Power Booster itself, no other filters or terminating elements
are required for safe, reliable data transmission.

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#### strantor

Joined Oct 3, 2010
5,226
so after all this research I've done on this stupid profibus transmission through sliprings crap, my boss comes to me today and tells me to start looking into wireless options. I wanted to shout "I've already done that! I brought you tons of information about it and you weren't interested!" Oh well, I get what I wanted from the beginning, and he gets to think that it was his idea; I guess it's a win-win of sorts

#### thatoneguy

Joined Feb 19, 2009
6,359
so after all this research I've done on this stupid profibus transmission through sliprings crap, my boss comes to me today and tells me to start looking into wireless options. I wanted to shout "I've already done that! I brought you tons of information about it and you weren't interested!" Oh well, I get what I wanted from the beginning, and he gets to think that it was his idea; I guess it's a win-win of sorts
I've had many people do that.

I'll let them know something will work a lot better a different way, and they'll flaty refuse, but happily pay you to find a work-around. Once enough time has passed (about 3 months), THEY come back with your original plan and claim they found the solution, and ask why you never mentioned it to them. Even if you have notes and calendar history dates, they are ignored. It was THEIR idea now, so it can be used.

It's a universal Dilbert "pointy haired boss" phenomenon.

#### strantor

Joined Oct 3, 2010
5,226
I've had many people do that.

I'll let them know something will work a lot better a different way, and they'll flaty refuse, but happily pay you to find a work-around. Once enough time has passed (about 3 months), THEY come back with your original plan and claim they found the solution, and ask why you never mentioned it to them. Even if you have notes and calendar history dates, they are ignored. It was THEIR idea now, so it can be used.

It's a universal Dilbert "pointy haired boss" phenomenon.
wow, so I guess it is a universal phenomenon. I wonder if there is some scientific significance to the 3 month constant?

#### thatoneguy

Joined Feb 19, 2009
6,359
wow, so I guess it is a universal phenomenon. I wonder if there is some scientific significance to the 3 month constant?
Not sure, but if it doesn't happen in 3, it comes back in 12 for sure. It's just bosses and having to admit they didn't know all they thought they did at the time, and after a certain period, enough new problems/projects have been in the middle where The Boss figures he can slip it back in as his idea.