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Discussion Starter · #1 ·
I'd be interested to know what you recommend as a good quality bearing manufacturer to use.
I want to replace the bearings in my router motor, and it seems that bearing quality makes a big difference on how the router performs.
I've been reading an article of a bad experience with the NSK bearings fitted to the Portamate router motor https://www.horizontalroutertable.com/nsk-bearings-100-failure/
 

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Made in China bearings is just about always a crap shoot...
I prefer to stay away from them...

That article on the NSK failures...
WTB under rated bearing were used for the task at hand - out of parameters... (load and speed)...
Porter cable does this... they like skateboard bearings...

for bearings. I like:
SKF...
Timken...
Fafnir...

talk to the people/experts at companies like:
Motion,
Whisler,
Kaman,
Canadian Bearings ......

if you are in a commercial theater, consider ceramic bearings...
 
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Discussion Starter · #3 ·
Thanks for your reply.
Seems SKF are the way to go and they are readily available in the UK.

One thing I can't find out absolutely clearly despite asking bearing suppliers, is should I fit standard bearings or C3 bearings in a router motor. I ask that because SKF do a super energy efficient bearing, which "...can provide more than twice the service life while reducing energy use"

I only want to replace the bearings once and the 'energy efficient' bearings are only a few pennies more than their standard bearings. But they only do the C3 fitment
 

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'energy efficient' bearings; sounds like marketing got a hold of that one...
they may ''help'' out where a machine runs 24/7...

I always thought of C3 bearings as ''sloppy''... (the ''C'' standing for ''Clearance'')
too much clearance and you get runout..

your primary concern is the sustained speed rating...
a bearing rated for 17/18K no load RPM in a 25KRPM machine is doomed to fail sooner than later...
 

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You can buy very good bearings but those may only be rated for up to 4000 rpm so they wouldn't last in a router. Watch for the rpm the bearing is rated for.
 

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Discussion Starter · #6 ·
You can buy very good bearings but those may only be rated for up to 4000 rpm so they wouldn't last in a router. Watch for the rpm the bearing is rated for.
Thanks for that. The SKF bearings I'm looking at have a reference speed of 41,000 r/min and a limiting speed of 21,000 r/min.

The limiting speed is explained as 'the empirically obtained value for the maximum speed at which bearings can be continuously operated without failing from seizure or generation of excessive heat'

So I reckon they should be suitable for a router motor that's used only intermittently at those speeds. Plus I can't find anything higher rated than that.
 

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Discussion Starter · #7 ·
Actually, the speed figures I quoted previously were for the larger bearing at the collet end of the router motor.

The speed figures for the smaller bearing at the brushes end are:
Reference speed: 70,000 r/min
Limiting speed: 36,000 r/min
 

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Discussion Starter · #8 ·
'energy efficient' bearings; sounds like marketing got a hold of that one...
they may ''help'' out where a machine runs 24/7...

I always thought of C3 bearings as ''sloppy''... (the ''C'' standing for ''Clearance'')
too much clearance and you get runout..

your primary concern is the sustained speed rating...
a bearing rated for 17/18K no load RPM in a 25KRPM machine is doomed to fail sooner than later...
SKF claim that their Energy Efficient bearings "...provide more than twice the service life while reducing energy use. Design improvements reduce frictional losses in the bearing by at least 30%..."

The standard SKF bearing has a 'Limiting Speed' of 34,000 r/min compared to the SKF Energy Efficient, which has a Limiting Speed of 36,000 r/min

The C3 bearing concerned me too, but what is 'sloppy' to me as woodworker may be miniscule to a precision bearing manufacturer. I'd be surprised if SFK produced new bearings that were sloppy.

Thanks for your input, much appreciated.
 

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The standard SKF bearing has a 'Limiting Speed' of 34,000 r/min compared to the SKF Energy Efficient, which has a Limiting Speed of 36,000 r/min
freudman
Did the above quote come from SKF?

I've been looking for a good quality bearing that will hold up in a 24,000rpm router!
The main (larger) bearing in a low-cost Chinese plunge router I'm modifying for a table set-up uses a regular 6004 bearing (20mm X 42mm X 12mm)

Doug
 

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I'm not absolutely certain but I think the 6004 is one of those common cheap bearings. You could find out by going on ebay and check their bearing sellers. The 608 is the skateboard bearing and it can be had for $8 a 10 pack which makes them $.80 each. Seems to me I saw deals on 6004 bearings too.
 

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"... but what is 'sloppy' to me as woodworker may be minuscule to a precision bearing manufacturer."
-Pete
Wait...what?! That's backwards isn't it?
 

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I'm not absolutely certain but I think the 6004 is one of those common cheap bearings.
Yeah I've seen them in packs of 10 for under $15, So they certainly are what I would call cheap bearings.

I've looked at some made by Nachi, NSK, & Timken! But none of them are rated above 18,000rpm.

Doug
 

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If you can read the code etched on the side of the bearing, put EXACTLY that in there. There are a bunch of bearing cross reference tables online, or email SKF, ***, NTN if you can't find an exact match for all the extension codes.

like everything else in the world, bearing makers manufacture their products in different places. I can tell you firsthand that the same bearings one maker can come from all over (and trust me, it is a royal pain in the butt because US customs levies duties on bearings based on country of manufacture, not where purchased from.... so getting them cleared can be a long affair). I have rarely had any issues with the 3 companies I listed above in the smaller bearing sizes, regardless of where they are made. For larger, high HP bearings I strongly recommend Timken as well.

I would blame a lot of bearing problems more on installation issues than on manufacturing issues.


https://www.skf.com/group/products/...ve-ball-bearings/permissible-speed/index.html
 

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If you can read the code etched on the side of the bearing, put EXACTLY that in there. ues.
why would you do that???
in the case of PC bearings. IMO, they fail because they weren't/aren't up to the task...
come on now.. that's throwing good money after bad...
a bearing used in a roller skate is used in a tool...
match SIZE/DIMENSION and make sure it's RATED for the task or exceeds it...
 
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Discussion Starter · #18 ·
I'm not absolutely certain but I think the 6004 is one of those common cheap bearings. You could find out by going on ebay and check their bearing sellers. The 608 is the skateboard bearing and it can be had for $8 a 10 pack which makes them $.80 each. Seems to me I saw deals on 6004 bearings too.
The 6004 does not mean it's a cheap bearing. It simply designates its size 20 x 42 x 12mm.
You can get cheap and nasty 6004 bearings and also very good quality 6004 bearings.
I found the best quality available to me. Now they are fitted the motor is quieter and much smoother than it was when brand new. I am well pleased.
 

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I found the best quality available to me. Now they are fitted the motor is quieter and much smoother than it was when brand new. I am well pleased.
which were???
 
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