Sedgwick MB Planer Thicknesser Full Refurbishment

[Jonthechippy]

Thanks,
It had occurred to me to swap the self aligning bearing with a same sized fixed double row bearing, or would that be asking for trouble?

 

[Jonthechippy]

Hi @deema ,

I'm trying to decide which bearings to get. I see you used a C3 tolerance bearing for the 6207 and a normal tolerance for the 2206.
Was there a reason for this? The Sedgwick manual doesn't mention specific tolerances and I'm no expert on this. Normal or C3 or doesn't it matter?
Thanks
Jon

 

[Sideways]

Rule of thumb, use a standard clearance for the bigger bearing at the pulley end and a C3 for the (sometimes smaller) bearing at the tail end. C3 isn't just about extra clearance for bearings that run at high speed, get hot and expand. It provides a little tolerance of imperfect axial alignment of the two bearing housings. You are going to clock and shim the two side castings that support the cutter block as precisely as you possibly can but they are separate parts bolted together not one casting bored through in a single operation so they will never be perfectly aligned. Motors likewise rely on the machining accuracy of 3 separate pieces.

Bearings on the sedgwicks - motor or block - don't run hot.

 

[Jonthechippy]

Thanks,
So your recommendation is for the 6207 to be standard clearance and the 2206 a C3?
The 2206 is a self aligning bearing which should surely take up the tolerance within the castings.
Jon

 

[Sideways]

That was just a quick rule of thumb for "conventional" deep groove ball bearings. It works for a lot of motors and spindles. I can't remember what a bearing is from it's number.
For the self aligning types, just do what @deema did. He's dilligent about the details so what he bought will have been right for the job
If the bearing is a self aligning type, then C3 is irrelevant to alignment tolerance.

 

[jetsetwilly]

Bit of an old thread but excellent reading. I have a question about the method of aligning the tables by (IIUC) tapping a side casting to move the slanted bearing faces and therefore the tables that bear on them. Wouldn't this also (slightly) cockle the cutter block bearings, since they're in the same castings? I suppose if the machine was originally set up perfectly coplanar and then the bearings line-bored, your method would actually improve cutterblock alignment!...