Atlas 618 - Timken Bearings

mattthemuppet2 said:
from memory the procedure I used (which I think is in the manual, maybe) is to tighten the collar at the back end of the spindle until the chuck can make only one revolution when given a decent spin by hand, then back the collar off by two teeths worth of rotation. So mark some part of the spindle and unscrew the collar enough for two teeth to pass the mark. That seemed to work for me. I gave each bearing a couple of good squirts of hydraulic jack oil every use and they went onto the next owner (friend of mine now) in just the same condition.
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Either my manual is different than yours or it's missing some pages. There is nothing about adjusting the bearings / spindle tightness. I got it to where I can give it a gentle spin (with no belt on) and it will do about 1.5 revolutions. If I back the tightening collar off by two threads, it seems like there is a decent gap between it and the next piece on the spindle. It seems pretty well adjusted so I guess we'll see. Hopefully the bearings aren't too tight.
 
hmm, I know I read it somewhere... :) The backing off of the collar is by 2 teeth of the spindle gear. Mark a tooth and the collar, then move the collar counter clockwise so that the 3rd tooth clockwise around the gear lines up with the mark on the collar.
 
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mattthemuppet2 said:
hmm, I know I read it somewhere... :) The backing off of the collar is by 2 teeth of the spindle gear. Mark a tooth and the collar, then move the collar counter clockwise so that the 3rd tooth clockwise around the gear lines up with the mark on the collar.
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Do you mean the 3rd tooth counter clockwise? That would be like a 20th of a complete turn. Clockwise seems like it would be almost a full turn, which also seems like too much.

Do you know where I can get this version of the manual that has this info in it?

Thanks, appreciate it! -John
 
I just realised that I got this bass ackwards and thought the gear was rotating, not the collar, sorry! You're right, mark a tooth on the spindle gear and mark the collar next to that tooth. Looking at the gear from the perspective outlined above count to the third tooth to the left of the marked tooth (counterclockwise). Turn the collar counterclockwise until the mark lines up with the tooth to the left.

Honestly no idea where I read this, it was years ago. I thought it was in the MOLO, but I'm guessing not!
 
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mattthemuppet2 said:
I just realised that I got this bass ackwards and thought the gear was rotating, not the collar, sorry! You're right, mark a tooth on the spindle gear and mark the collar next to that tooth. Looking at the gear from the perspective outlined above count to the third tooth to the left of the marked tooth (counterclockwise). Turn the collar counterclockwise until the mark lines up with the tooth to the left.

Honestly no idea where I read this, it was years ago. I thought it was in the MOLO, but I'm guessing not!
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No problem!... and am I supposed to tighten the collar first until the chuck can spin about 1 turn by hand with or without the belt, do you know? Thanks!
 
mattthemuppet2 said:
I just realised that I got this bass ackwards and thought the gear was rotating, not the collar, sorry! You're right, mark a tooth on the spindle gear and mark the collar next to that tooth. Looking at the gear from the perspective outlined above count to the third tooth to the left of the marked tooth (counterclockwise). Turn the collar counterclockwise until the mark lines up with the tooth to the left.

Honestly no idea where I read this, it was years ago. I thought it was in the MOLO, but I'm guessing not!
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And total apologies as I read your first helpful reply on the last page incorrectly! You did say teeth and I interpreted that as "threads"! Sometimes my mind is ridiculous.
 
We'll figure it out together says the blind man to the priest:)
 
JRT said:
No problem!... and am I supposed to tighten the collar first until the chuck can spin about 1 turn by hand with or without the belt, do you know? Thanks!
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Without the belt or anything else that will affect the spindle rotation. You can also do it by feel, you can tell when it starts to get tight
 
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John,

We have, in downloads, an Atlas Technical Bulletin on the 612 and 618 that covers disassembly and re-assembly of the 6" headstock, including how and why to adjust the preload. However, because the storage of the 2000+ PDF files in Downloads costs us each month, access to Downloads is restricted to Donors (any level from $10.00 per year up). You may not wish to become a donor, but if you do, here is how to most easily find the TB, (and other files on the 618). I don't think that you have been in the hobby long enough to have "stuff" that you might want to sell but I will mention that for historical reasons (at the time it was the only level) access to selling also requirs Donor status but at @ $25.00. The code that we use is from PayPal and it has no provision for changing amounts other than at the end of a year. I don't know what it would do with a second donation in mid-year but I doubt that it would involve any rebatel

In the main tool bar at TOS, click on Downloads.

Click on Click Here 1st

Click on Click Here 2nd

Click on Atlas/Craftsman

Click on A/C Lathes
(Less Drawings & Catalogs)

Click on A/C Lathes - Repairs & Technical
Bulletins

move to center of page

Scroll down and locate Atlas Tech Bulletin 06 612/618 Back Gear Instr Rev 3 ...

Download the file (and any others that you want). It is a PDF.
 
I’ll
wa5cab said:
John,

We have, in downloads, an Atlas Technical Bulletin on the 612 and 618 that covers disassembly and re-assembly of the 6" headstock, including how and why to adjust the preload. However, because the storage of the 2000+ PDF files in Downloads costs us each month, access to Downloads is restricted to Donors (any level from $10.00 per year up). You may not wish to become a donor, but if you do, here is how to most easily find the TB, (and other files on the 618). I don't think that you have been in the hobby long enough to have "stuff" that you might want to sell but I will mention that for historical reasons (at the time it was the only level) access to selling also requirs Donor status but at @ $25.00. The code that we use is from PayPal and it has no provision for changing amounts other than at the end of a year. I don't know what it would do with a second donation in mid-year but I doubt that it would involve any rebatel

In the main tool bar at TOS, click on Downloads.

Click on Click Here 1st

Click on Click Here 2nd

Click on Atlas/Craftsman

Click on A/C Lathes
(Less Drawings & Catalogs)

Click on A/C Lathes - Repairs & Technical
Bulletins

move to center of page

Scroll down and locate Atlas Tech Bulletin 06 612/618 Back Gear Instr Rev 3 ...

Download the file (and any others that you want). It is a PDF.
Click to expand...
do the membership thing in a few days, thanks for all of this.
 
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