Thread: Router Bit: Change Bearing?

Check the CMT website. I think you'll find that the bearings come in standard increments (1/8" or so), so if you want one that's only 1-2mm smaller it might not be easy to find

I have bought one at bunnies about two months ago

Originally Posted by MVL Furniture

HI

I recently purchased a CMT 18mm 45 degree Chamfer bit, thing is i wanted a 19mm but was handed an 18mm by the store. Unfortunately i used it before i realised so i cant return it.

Anyway I noticed that bearing at the top of the bit is larger than the cutting edge at the top. It over hangs by a mm or two

So i think i can remove the bearing and add on a smaller one which will lengthen the cutting edge and mean i have the bit in the need size i need

I need advice on where i can get bearings from as i can only find a tuning kit on Carbatec's website but it doesn't specify the size of bearings

any ideas?

Marty

Hi Marty

What is the part number of the bit you purchased?
The only 45 degree, 1/2" shank bearing guided bits I can see in the CMT catalog are 18 mm (Part number 836.920.11) and 26 mm (Part Number 836.950.11).

the next smaller bits have 8 mm or smaller shanks so it's unlikely the bearings for those bits will fit

Have a look at one of the specialist bearing suppliers, Google 'Bearing suppliers Brisbane'. Take your router bit in and show them what you want. The range is absolutely astounding and the prices tend to be very affordable.

Give Statewide Bearings a try, I use them whenever I need belts, bearings or pulleys and they're always very helpful. Pretty sure they have a branch in Brissie.

Originally Posted by MVL Furniture

HI

I recently purchased a CMT 18mm 45 degree Chamfer bit, thing is i wanted a 19mm but was handed an 18mm by the store. Unfortunately i used it before i realised so i cant return it.

Anyway I noticed that bearing at the top of the bit is larger than the cutting edge at the top. It over hangs by a mm or two

So i think i can remove the bearing and add on a smaller one which will lengthen the cutting edge and mean i have the bit in the need size i need

I need advice on where i can get bearings from as i can only find a tuning kit on Carbatec's website but it doesn't specify the size of bearings

any ideas?

Hi Marty

tonight I had a good look at the CMT catalog.
It looks like all of CMT's bottom bearing guided chamfer bits use the same bearing (791.003.00), washer (990.423.00) and screw (990.058.00).

If the bit you purchased is the one you were trying to sell in your other post (CMT bit number 836.920.11) the cutting edge is only 18 mm deep. Even if you can find a slightly smaller bearing, you won't be able to cut a 45 degree chamfer with it bigger than about 17.9 mm because the geometry of a 45 degree right triangle will defeat you.

I believe your only option is to purchase a larger 45 degree CMT bit -- part number 836.950.11 -- or one from another manufacturer. BUT a quick look at the Freud and Amana Tools sites suggests that 45 degree chamfer bits in the size you are after, come in "standard sizes" of 5/8" (~16 mm) and 1" (~25 mm)