Spindle Bearing Replacement For The Rf-31 Mill/drill

[Ludvigsen]

so, I have continued "working" on my spindle and the quill and tried to turn the nut down the shaft and I could turn the nut all the way down over the groove above the locking nut has "no stop". So how to know how much I need to tighten the nut, how big torque, should I just tighten it easily and lock it? and it's more, when looking at the lower bearing: it's lying on the lower part of the spindle this part has a diameter of 62 millimeter and that mean that this surface are covering both inner and outer part of the bearing!! i should make a spacer here as only work as a spacer for the inner part of the bearing of 40mm don't you think? here is the link to FAG's lower bearing https://medias.schaeffler.com/medias/en!hp.ec.br.pr/72..-B-2RS*7207-B-XL-2RS-TVP . where d2 is say 45mm. so 40mm x 1mm. spacer should be good for compensating and correcting for should be good and take a one millimeter thickness disk, when I am looking at Mikey's spindle I can see that it's different from mine, as you can see on this updated drawing :

 

[Techee]

Mikey & Canuck75, thank you for this thread.

A question for both of you;

How are the bearings performing in both of your mills?

I have a Central Machinery, Chinese, Grizzly G0705 copy that I bought new from a guy that never used it. I stole it for $500.

I am surprised at how good the quality is, but I am looking at doing this bearing replacement.

Thanks guys!

 

[mikey]

Mine is basically unchanged since I did this bearing replacement - still accurate, temp hasn't changed so preload is stable and there have been zero issues. If you do change the spindle bearings, I would also change the drive sleeve bearings while you're in there. It makes a big difference and will reduce wear on the spindle bearings.

 

[Techee]

Thanks Mikey.

Do you have drive sleeve bearing recommendations?

 

[mikey]

Yup, here you go.

 

[Techee]

No attachment visible

 

[mikey]

See the highlighted/blue text in the post above yours? That's a hyperlink to the article with bearing info.

 

[Techee]

Thanks Mike!

Jack

 

[DavidR8]

I'm working on ordering a set of these bearing. Looks like part numbers have changed slightly in the intervening years.
Seems now it's as shown. The supplier is confirming that they are sealed.
Cost is $44 for the 7206 and $47 for the 7207. Not sure why they are $3 different...

 

[mikey]

If you can get them for that price, I would do it. P5 bearings usually aren't that cheap.