[Biggs427]

I need to change the bearing in my router. Bottom is 6004-2RS and top is 608-2RS. Pretty common...

Would it help to put AC bearings instead? 7004 and 708. Is it even worth it since the price is greater ?

I usually doesn't plunge that much I try to ramp or helix whenever possible.

[ger21]

In a router, the bottom bearing normally supports the spindle axially, and the top bearing just holds it radially.
With a spindle that uses AC bearings, there are a pair of bearings at the nose that hold it axially.
I don't think it would work as well putting a single AC bearing at both ends.
Also, an AC bearing usually won't have a seal, so dust may be an issue?

[Biggs427]

You're right about dust, it will be an issue; I didn't knew that AC bearing didn't had sealed versions.

I think I will continue with 6004 and continue to pay attention on how I ramp in material.

Thanks

[mactec54]

You're right about dust, it will be an issue; I didn't knew that AC bearing didn't had sealed versions.

I think I will continue with 6004 and continue to pay attention on how I ramp in material.

Thanks

It would not work, unless the router Design was changed as to how the Bearing are installed, anything is possible, yes you can get sealed AC bearings, all the Chinese router spindles have sealed AC bearings, just remember, these Bearings are running at high RPM and only have grease lube, the bearings are small also in hand routers, so don't last that long anyway

[wizard]

I need to change the bearing in my router. Bottom is 6004-2RS and top is 608-2RS. Pretty common...

Would it help to put AC bearings instead? 7004 and 708. Is it even worth it since the price is greater ?

Feasibility depends entirely upon the routers design. For angular contact bearing to work they must be constrained axially and with some router designs that would be very difficult to do. Having two different sizes of angular contact bearings isn't ideal either.

I usually doesn't plunge that much I try to ramp or helix whenever possible.

One option for motors is to modify the arbor and one end bell to house a set of angular contact bearings. This is far easier to do on a 3 phase induction motor so probably isn't worth the grief on a router. The idea those is that the end bell is replaced with a unit that has enough bulk to properly implement a bearing housing for angular contact bearings. You then have to replace the motor start with a new one that properly fits those bearings and can be locked to the bearings.

The problem here of course is that a Chinese spindle basically has all of this done for you and at a cost that frankly can't be beat.

Now given all of the above there are a lot of engineering issues you need to address. For one angular contact bearings are available in a number of classes, preloads or no preload at all. You might even find sealed examples. The problem is you need to select the proper bearing for your approach to using it. The wrong bearing or mounting solution, can lead to premature failure or worse performance than a radial ball bearing. Personally I'd leave all these details to a spindle manufacture.