# Gear Problem?



## tmenyc (Nov 13, 2019)

A friend was here to see my new shop table, a 1920s Singer commercial sewing machine table, refinished in epoxy. 
I ran the Logan.  He's a skilled shop guy, can do anything, is not a machinist.  After listening for five seconds, he said "you have a gear that's off, let's see."  So we opened it, he pinpointed what he thinks is the issue, a gear that is out of round, or a gear race out of round.  It's in the video below.  I can't tell if it's getting worse since I hear it all the time. 
I'm hoping the video shows the issue; it's the center gear, I think.  If anyone knows how, please let me know? 

__
		https://flic.kr/p/2hKrKC2
In the two photos, the large gear does not appear to be exactly aligned; 



Also, please point me to what is wrong and how to fix it? 
Many thanks, as always.
Tim


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## cathead (Nov 14, 2019)

Tim,

It doesn't look to be tracking straight.  This means the center hole where it is driven not perpendicular to the plane
of the gear.  That being the case, one could bore out the center and fit in a new center that IS perpendicular so the gear
will run true.  I don't think the gear itself would be out of round, just not running true.

Looking at the video, you can see the  light reflecting  back and forth indicating that the gear is wobbling.  The other possibility
would be that the shaft holding the gear is bent.  That being the case, one could remove the gears and straighten the shaft.
I would inspect the gear as a first course of action since that what it looks like on the video.


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## HarryJM (Nov 14, 2019)

Sure does look like the top gear is not aligned to the bottom one as I can see small ridge where the top gear teeth on the left side is not worn down. Is there a missing shim between the two top gears? Or shim on left side of bottom gear?


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## tmenyc (Nov 14, 2019)

thanks, appreciated.  I got an answer offline that might also be the problem, that the bushing in there is worn and off true, so then everything else is.  This weekend I'll take it apart and check all of these options.  I've learned my way through each subassembly as I've needed to, so now it's the gears...

Tim


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## tmenyc (Nov 17, 2019)

Update:  A fellow 820 owner and I connected over a video call and he walked me through adjusting the gears.  I think they just worked loose over time and use, and I didn't know how to maintain them except for oil.  Now I do.  Now it hums. 

However, a new question arose:  how does one lubricate the gear stack inside the quick change gear box?  The surrounding oil points all appear to lubricate shafts, and there is no easy access to those gears.  There is no reference to oiling these gears in the manual. 

Many thanks!
Tim


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## Latinrascalrg1 (Nov 17, 2019)

Glad you fixed it.  Id like to share a little diagnostic trick for trying to search out where a particular noise is coming from within a symphony of sounds.   Use A long screw driver or metel bar/pipe as a Stethoscope by placing the tip of your screw driver solidly against a non moving part and the handle against your ear as you probe around for the offending noise.


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## tmenyc (Nov 17, 2019)

thanks, good one!  This time, the source of the sound was all too obvious, but that's a great tip.
Tim


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## HarryJM (Nov 18, 2019)

Latinrascalrg1 said:


> Glad you fixed it.  Id like to share a little diagnostic trick for trying to search out where a particular noise is coming from within a symphony of sounds.   Use A long screw driver or metel bar/pipe as a Stethoscope by placing the tip of your screw driver solidly against a non moving part and the handle against your ear as you probe around for the offending noise.


Used the screw driver/stethoscope tool many a time as a motorcycle mechanic.


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## matthewsx (Nov 18, 2019)

tmenyc said:


> Update:  A fellow 820 owner and I connected over a video call and he walked me through adjusting the gears.  I think they just worked loose over time and use, and I didn't know how to maintain them except for oil.  Now I do.  Now it hums.
> 
> However, a new question arose:  how does one lubricate the gear stack inside the quick change gear box?  The surrounding oil points all appear to lubricate shafts, and there is no easy access to those gears.  There is no reference to oiling these gears in the manual.
> 
> ...



If you lube a shaft the oil should make it's way to the gears riding on it through centrifugal force.


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