Lubricant for plastic on metal
op...@hotmail.com
signs of wear on the plastic moving part. Also, plastic "dust" is
fouling the contacts. Would heavy lithium grease, mainly because I
have lots of it already, be a good candidate here after cleaning?
Also read this while Googling;
"I think this is an area of rapidly diminishing returns. The
difference
between a good lubricant, a better lubricant, and the best lubricant
is
trivial compared to the differences between lubricated and
unlubricated"
Lloyd E. Sponenburgh
c4b7-4453-900...@19g2000yqu.googlegroups.com:
> I have some cheap electrical pushbutton switches that are showing
> signs of wear on the plastic moving part. Also, plastic "dust" is
> fouling the contacts.
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
Karl Townsend
<op...@hotmail.com> wrote in message
news:8b2421c6-c4b7-4453...@19g2000yqu.googlegroups.com...
I'd use spray silicone lube. Grease will just attract dirt.
Karl
RBnDFW
Silicone spray is what i'd be using.
op...@hotmail.com
> the problem. Lubrication does little good when there are burrs and other
> defects scraping the moving parts.
Actually, that's not the problem in this case. It's a push-to-make,
push-to-break switch. The moving contact is a thin metal washer,
literally, with a plastic rod through its center. The washer is
shaving the rod as it moves and the wear pattern is obvious. Granted,
I'm purposely subjecting it to over 100 operations per day, far in
excess of normal usage.
On Mar 25, 9:26 am, "Lloyd E. Sponenburgh"
<lloydspinsidemindspring.com> wrote:
>
Lloyd E. Sponenburgh
62fd-45c5-8c6...@k17g2000yqb.googlegroups.com:
> The washer is
> shaving the rod as it moves and the wear pattern is obvious.
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
op...@hotmail.com
> edges rounded, and sidewalls polished -- or not?
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.
> Buy some good escapement-operated push-push switches, and they'll last
> hundreds of thousands of operations.
That's at least 54 years at 5 operations per day. Overkill for the
purpose.
On Mar 25, 11:10 am, "Lloyd E. Sponenburgh"
<lloydspinsidemindspring.com> wrote:
>
op...@hotmail.com
Thanks guys.
On Mar 25, 10:24 am, RBnDFW <burkhei...@gmail.com> wrote:
>
Ned Simmons
>> And that would be because the hole in the washer was cleanly de-burred,
>> edges rounded, and sidewalls polished -- or not?
>
>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.
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.
--
Ned Simmons
op...@hotmail.com
> situation.
Me too. I may just subject one of them to 10,000 operations using the
Z axis of a CNC machine. Heck, something else in the switch may give
before the plastic rod.
On Mar 25, 11:48 am, Ned Simmons <n...@nedsim.com> wrote:
>
whit3rd
[about a switch with a wear issue]
> ... 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.
>
> > Buy some good escapement-operated push-push switches, and they'll last
> > hundreds of thousands of operations.
>
> That's at least 54 years at 5 operations per day. Overkill for the
> purpose.
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).
op...@hotmail.com
Overkill makes no economic sense in my case. I'm currently testing the
switch, with lithium grease applied, for 10,000 operations on a CNC
machine. I'm good if it survives that. Thanks!
On Mar 25, 4:34 pm, whit3rd <whit...@gmail.com> wrote:
>
Stormin Mormon
the metal washer hole, to make it smoother.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
<op...@hotmail.com> wrote in message
news:111dc70b-62fd-45c5...@k17g2000yqb.googlegroups.com...
op...@hotmail.com
> 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 in China, needs a helping hand.
On Mar 25, 10:45 pm, "Stormin Mormon"
<cayoung61**spambloc...@hotmail.com> wrote:
>
Stormin Mormon
switches to correct. In that case, the dab of grease makes
more sense. Thanks for letting us know how it worked out.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
<op...@hotmail.com> wrote in message
news:5b4d56dd-c614-44c1...@n34g2000yqb.googlegroups.com...
Bob Engelhardt
> ... I'm currently testing the
> switch, with lithium grease applied, for 10,000 operations on a CNC
I like the outside-of-the-box use of CNC. Clever.