Logan 820 Upgrading countershaft to ball bearings

MathewsLG

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As I work through my Logan 820, I am finding, and for the most part, successfully fixing the various issues I come across.

While installing a new belt, I noticed that the countershaft and "self-lubricating" bearings were quite worn out. The shaft was a simple .750" shaft that simply needed to be cut to length, but the brass bearings were quite worn out. I have considered cutting new brass bearings and pressing them into the original mounts, but I wanted to get some thoughts on the pros/cons of making a set of ball bearing mounts.
 

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Ball bearings would be nice, but it seems like a lot of work. You have the same set up as I do on my Model 200. I suppose you could machine
some larger OD bearing blocks to accept a bearing: maybe needle bearings would fit. But, the support arm would need machining to fit
the larger parts in. If you have a mill, I guess that would be easy. The problem I see is alignment of the bearing bores to the axis of the shaft.
The set screws on the existing bearing blocks probably don't support it accurately enough for a bearing, though of course with bushings
it doesn't matter. The stock bushing arrangement works fine once you put new parts in. I replaced my shaft and bought 4 oilite bronze bushes
from McMaster-Carr. Works fine.
 
I replaced my bronze oilite with new ones from McMaster-Carr. My originals were pretty bad. I don't recall what size they were but they were a stock size and relatively inexpensive, less that $3 each. I figure they lasted 50+ years, a new set will last my lifetime with proper lubrication.
 
Your second picture shows a V-belt pulley, is that on your 820? I believe all 820's came with flat belts. Also beware of stacked set screws on those pulleys... been there done that.
 
If you go with needle bearings you would need to replace the shaft with a hardened steel one, but it's certainly doable
-Mark
 
Your second picture shows a V-belt pulley, is that on your 820? I believe all 820's came with flat belts. Also beware of stacked set screws on those pulleys... been there done that.

At first I didn't get what you were looking at. Hummm. Yes, to the best of my knowledge, factory 820's are a vee belt from the motor to the double diameter flat counter-shaft pully. Flat belt from the counter shaft to the spindle. That said, the preface to the 800 manual states:

During the production of the Lathes, many parts were changed, and as a result, some assembly diagrams may have more than one version in this manual. Where possible, we have made note of the Serial Number break point. Compare this to the Serial Number of your Lathe, and also compare the appearance of the parts to determine which is appropriate for your Lathe. If all else fails and you need a replacement part, contact us with dimensional data from your old part. The Serial Number is stamped on top of the Bed, near the right hand end of the Lathe, in the trough between the front “V” and Flat ways.


Ron
 
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I have a 825, so a slightly different setup for the belts, but I am a fan of sealed ball bearings. I have been going through and replacing some of the oilite bushings with ball bearings on the gear train for my lathe with ball bearings and it is so much quieter. I think this countershaft would be a great application for needle roller bearings. As was stated, you need a hardened shaft. McMaster does sell "shaft liners" for needle roller bearings. Since your shaft is already a little chewed up, you could turn down the shaft, press on the liner and then use the roller bearings.
 
The picture I was referring to was "countershaft 1.jpg" above, I assumed that was a picture of the countershaft and the 3 step cone pulley. Maybe I'm wrong but that looks like a V belt pulley to me. I believe the later 1800 series used V belts for the 3 step cone pulleys but the 800 series all used flat belts for the 3 step cone pulleys. I believe both used the "V to flat" for the motor drive end.

See the Logan FAQ: http://www.lathe.com/models.htm there is a column for "drive belt".
 
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