Replacing headstock bearings

[John Hicks]

I'm wondering if there is any benefit to replacing oem Chinese/Taiwanese bearings with higher grade ones?

 

[Owen Lowe]

I would say not if you're not experiencing any problems with excessive play or noise; I think the only benefit would be peace of mind. Can you see the manufacturer brand markings on the bearings? (i.e., perhaps they may not be as poor quality as you imagine).

 

[Roger Chandler]

I would say that if you are speaking of bearings on the Harvey T-60 that the bearings are already premium bearings. Harvey, Powermatic uses high end parts for their lathes.

 

[Richard Coers]

Do you actually know where the bearings are made, or just where the lathe is made? If it ain't broke, don't fix it.

 

[Joe Kaufman]

Is there a definition or dimensional specification for higher grade or premium single row ball bearings? There are specifications for bearing clearance class, for example:

ISO clearance class SKF designation Internal clearance
- C1 Smaller than C2
Group 2 C2 Smaller than Normal
Group N - Normal
Group 3 C3 Greater than Normal
Group 4 C4 Greater than C3
Group 5 C5 Greater than C4
For a wood lathe application there is no point specifying a C2 reduced clearance class bearing as it will tend to operate at a higher temperature and be more sensitive to lubrication.

If you specify a premium bearing you are probably relying on the supplier for his experience or opinion, which may or may not have some basis. Unless the bearing is in stock you don't know country of origin until it in your hands. I had a issue with spindle noise on my Powermatic while under warranty. Powermatic supplied no name Chinese bearings and the finish surfaces on the face of the bearings was such that it may be indicative of the interion finish. I purchased and installed NACHI bearings made in Japan. A few months ago I was going to change the belt and purchased another set of NACHI Bearings and didn't notice until I got home that they were made in India, which look OK. I decided to order a set of SKF Bearings (American Manufacturer at one time) and I was surprised to see Made in Bulgaria which also look OK. Not to step on any toes, but my opinion the word premium or high grade is a term not a quantitative specification. Incidentally, the PM 3520 originally came with spindle bearings with Taiwan stamped on the shields, again they looked OK.

 

[Bill Boehme]

In addition to what Joe Kaufman said, normal clearance bearings are the right choice for most woodworking machines. It would be a mistake to think that tighter tolerance bearings equates to better bearings.

A bearing that is starting to fail will usually let you know by making noise that might be a slight clicking sound or a growling sound. A good way to test your spindle bearings is to loosen the drive belt and then use the handwheel to rotate the spindle while listening carefully.

 

[RichColvin]

I replaced the ball bearings on my Chinese metal lathe with roller bearings. I had to replace the broken plastic drive gears anyway (with metal ones), so it was worth replacing the bearings at the same time. But, as Richard Coers noted, if you are not having problems, don’t take this on. I had to make a number of wooden fixtures during the process to enable my machinist son to do the work.

If the spindle is binding, or has excessive play, consider this. But, be prepared for a whole lot more work than you’d expected. Well, at least that’s what I found.

Rich