Adding a bearing to a router bit

[Arvind Srivaths]

A thread already exists on this topic but my post did not get any response. I thought posting in this forum may get a response as the members here might have tried something similar. Is it a good idea to add a bearing below the bit (in my case, a round over bit) and cut a small grove after leaving space for the bearing and put a C ring in the groove to hold the bearing? It does not impact the grip on the bit as the bit will still have the same length inside the collet. The only question is if a C ring is sufficient to keep the bearing on the bit without slipping out. Also wondering why current bit designs (at least the ones I have seen) use a screw to hold the bearing instead of a C ring - is a screw better than a C ring. It seems to me that a screw can come loose because of vibration but vibration can never get a C ring off. Or, even better, why not use a washer that is heated till the hole expands and put into the groove where it fits snugly once it cools? That will never come off.

Thanks,
Arvind

The old thread:
https://sawmillcreek.org/showthread.php?61738-Adding-bearings-to-bits

[Lee Schierer]

I've never done this nor had the need to add a bearing to the router bit shank. It could be done if you have access to the proper machining tools. You would want to have a washer between the inner race of the bearing and the top of the bit to insure that the shields and outer race don't contact the top surface of the round over bit.

Screws are used because it allows most users to replace the bearings with just an allen wrench. I've never had a screw loosen on a bit during use. Using a press on washer would make it nearly impossible to change the bearing.

[Mark Gibney]

Early last year the bearing came off a flush trim bit I was using to shape a piece for a client. It gouged a wallop out of the top and I had to start over. Ruined my day!

I had never removed that holding screw since buying the router bit, and now I'm nervous when I'm trimming something I've a lot of time / money into no matter what bit I'm using.
I've considered a little Loctite on the threads. Bad idea?

[Alex Zeller]

I would be cautious of trying to make a groove for a clip in the shank of a router bit. Get it wrong and it could break sending the cutting portion flying. I think the reason why a collar with a screw is used is it doesn't weaken the shank and nothing special is needed to be done to the bit.

[Arvind Srivaths]

Early last year the bearing came off a flush trim bit I was using to shape a piece for a client. It gouged a wallop out of the top and I had to start over. Ruined my day!

I had never removed that holding screw since buying the router bit, and now I'm nervous when I'm trimming something I've a lot of time / money into no matter what bit I'm using.
I've considered a little Loctite on the threads. Bad idea?

Thanks Mark - that does support my intuition that a C ring is a better design than a screw. If it had hit you instead of the piece, it could have been disastrous.

I don't see how Loctite can hurt - especially if you don't intend to change the bearing.

Arvind

[Arvind Srivaths]

I've never done this nor had the need to add a bearing to the router bit shank. It could be done if you have access to the proper machining tools. You would want to have a washer between the inner race of the bearing and the top of the bit to insure that the shields and outer race don't contact the top surface of the round over bit.

Screws are used because it allows most users to replace the bearings with just an allen wrench. I've never had a screw loosen on a bit during use. Using a press on washer would make it nearly impossible to change the bearing.

Thanks, Lee. Yes, I forgot that people like to change the bearing to move the profile closer in and farther out.

Arvind

[Lee Schierer]

I've considered a little Loctite on the threads. Bad idea?

Use the blue LocTite not the red.

[Bill Dufour]

A c-clip may be more likely to snag and throw stuff into your face? If it touches anything.
Bill D

[Mark Gibney]

Hey thanks - I knew that somewhere in the fog!

[glenn bradley]

I have some profile that uses a snap ring to hold the bearing although the exact profile escapes me now. It sounds like you want to add an additional bearing between the cutter profile and the collet(?). I have a collection of bearings and use them to expand the profile capabilities of some bits. I have 1/2" ID collars that are standard on some profiles that use a shaft mounted bearing. I also have bearings that fit the 1/2" shaft with varying OD's. IF you are Jones-ing to machine your bit's shaft I would go ahead. A collar that is intended for what you are trying to do may be a more reversible solution.