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Longevity of nylon plain/sleeve bearing on aluminum rod

Longevity of nylon plain/sleeve bearing on aluminum rod

Longevity of nylon plain/sleeve bearing on aluminum rod

(OP)
First off, I am not a engineer, and I understand I am in the big boys' playground here, but if anyone has a chance to humor me on this that is wonderful. I have done a little research to try to get my terms down.

SHORT QUESTION:

small nylon bolt with a hole drilled through it and an approx 1/16" aluminum rod running through it. Rotating back and forth continuously with water on the joint. Will this last a long time?

LONG QUESTION:

Working on finishing up a prototype of a fountain which which has been accepted to be installed at a hospital here in Washington state. Donating prototype to an arts center charity auction. The design is based on an old japanese fountain/music instrument: http://en.wikipedia.org/wiki/Suikinkutsu

I'm using two hinged mechanisms which tips over when filled with water, then rights itself (shishi odoshi/japanese "Deer scarer") to get an intermittent water release as opposed to a maddening DRIP DRIP DRIP.

A picture/video is worth a thousand words: http://www.youtube.com/watch?v=EOc-EnNtuz4
(yes, one of them stops in the video, something was misalinged. they have been running for several days now with no problems)

Here is the assembled piece:
http://www.youtube.com/watch?v=IpX9l4-uoVA&feature=channel_page

So, these little hinged mechanisms will be inside the steel sphere coated with a sealer, so we want them to last at least 3-5 years!

More details: The joint stays wet. Aluminum rod w/ nylon bolt. Don't know too much about the nylon I have, hardware store lists it as "transparent nylon" from Serv-A-Lite company (couldn't find detailed info at http://www.servalite.com/).

Is this a decent configuration and combination of materials? Will it last a long time?

In addition to a rough idea of how long before this nylon starts wearing through, I'm also open to suggestions on a better way to do this. A better type of small bearing setup to use? I discovered during testing that the overall weight of mechanism must be small relative to the weight of the water which fills the receptacle. We also have considered using two pumps and just switching them on and off at several second intervals.

Finally, I would like to thank those who responded to my one previous post in July 07: cvg, bridgebuster, fattdad, and TMalloy, which helped me create the leaning section of "American Aqueduct" (this piece is called "American Suikinkutsu"...I decided that interpretation of international, historic architecture and water structures is my theme) http://www.youtube.com/watch?v=h-UKsSnFQYs

That's all folks...thanks.

RE: Longevity of nylon plain/sleeve bearing on aluminum rod

I am not that worried about the nylon. The load is quite low and most types of nylon respond well when lubricated with water. what i am worried about is the Al rod. after prolonged use, the Al might be attacked by the water or ingredients that are in the water, and thus either get damaged and or abrasive to the nylon. i would either use stainless steel (which in combination with the nylon might give somewhat more friction)or coat the Al with some kind of a laquer to prevent chemical attack of the Al.  

RE: Longevity of nylon plain/sleeve bearing on aluminum rod

(OP)
So aluminum is more reactive to water than stainless? OK, I will pick up a stainless rod then and switch it out. Thanks for the feedback!

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