Lubricant for plastic on metal

" snipped-for-privacy@hotmail.com" fired this volley in news:8b2421c6- snipped-for-privacy@19g2000yqu.googlegroups.com:

The cheap styrene buttons rubbing on a poorly machined switch barrel are the problem. Lubrication does little good when there are burrs and other defects scraping the moving parts.

Were I to make one from scratch, the barrel would be reamed, and the buttons made of polypropylene or HDPE.

LLoyd

I'd use spray silicone lube. Grease will just attract dirt.

Karl

Silicone spray is what i'd be using.

Actually, that's not the problem >

" snipped-for-privacy@hotmail.com" fired this volley in news:111dc70b- snipped-for-privacy@k17g2000yqb.googlegroups.com:

And that would be because the hole in the washer was cleanly de-burred, edges rounded, and sidewalls polished -- or not?

My underlying point was that cheap switches are cheaply made.

Buy some good escapement-operated push-push switches, and they'll last hundreds of thousands of operations.

LLoyd

Not really, it's cleanly deburred, however, the washer being so thin and the arrangement only centered axially by two springs, it wobbles, allowing the washer to "whittle" the rod while operating.

That's at least 54 years at 5 >

Thanks guys.

>

If the edge of the washer is thin enough or sharp enough that it's scraping away the plastic, it'll also do a good job of removing the lube. I'd expect grease to last somewhat longer than silicone in this situation.

Me too. I may just subject >

[about a switch with a wear issue]

Overkill kills the problem. Then the problem stays dead. Overkill is good.

Mass-produced microswitch mechanisms are inexpensive and very durable, and available with LOTS of actuator choices. Buy some, or get 'em from scrap equipment (every dead microwave oven has two nice microswitches in the interlock system).

Overkill makes no ec>

Some kind of metal sleeve around the plastic rod? Or, sand the metal washer hole, to make it smoother.

I have 175 of these switches to correct. Just adding grease (a 2 minute exercise) was sufficient to allow for 10,000 operations without any signs of wear or falling apart. A day vs night comparison to just

800 operations without the grease. Already have the grease, bought it around 14 years ago.

Sometimes, dirt cheap, made >

I missed the moment where you wrote that you had a LOT of switches to correct. In that case, the dab of grease makes more sense. Thanks for letting us know how it worked out.

I like the outside-of-the-box use of CNC. Clever.