Cutterhead bearings on 8″ jointer
Badjeros
| Posted in Power Tools and Machinery on
I have a King Canada 8 inch long bed jointer. Last week the cutter head bearing on the pulley side began to ‘sing’. The pillow block seemed quite warm, and after loosening the drive belts the same bearing had a definite burr. This jointer is only about 2 years old and out of warrantee. I decide to replace both bearings on the cutter head, having pressed the new ones on this afternoon. However, the pulley side bearing is still running quite hot to the touch. The drive belts are snug but not tight, about 1 1/2″ slack, and there does not seem to be any tight spots in the cutter head rotation. The cutter head freewheels quite readily. My question is this: Does this heat seem unusual?
Thank you in advance.
-None-
Edited 8/27/2004 6:49 pm ET by none
Replies
The belt drive will generate friction that would heat the pulley and conduct back into the bearing, this could be an alternate cause for the temperature rise.
With the bearings fully cooled down, start the planer and take a quick pass or two on a board, then shut the power off and check if the pulley is getting warm before the bearing heats up. Repeat this test a few times, if needed, and you should get a sense of whether the bearing is getting hot first or if the pulley is the source of the heat.
If the source of the heat is the pulley, check the condition of the belt and the pulleys, the pulley alignment, and the belt tension. A glazed or stiff belt, misaligned pulleys or low tension can all generate excess heat. Even a good belt drive will generate some heat but if the pulley is getting hot quickly there may be a problem.
In any case, if you installed the bearings properly, and there is nothing wrong with the drive, there isn't much you can do with a sealed bearing except replace it again, so I'd suggest just using the machine and checking the bearing occasionally for early failure.
John W.
JohnW,
Thank you for your input. I checked the pulley as you suggested, both for tension and alignment, however I fear the bearing is getting warmer than the pulley. I very well may have squashed the bearing slightly when pressing it onto the shaft. My only other hope is that once the tightly packed bearing settles in, it may operate at a lower temperature. Failing that, it's back to the job of putting new bearings in once again. I will just continue using these ones until they fail.
Thank you once again.
-None-
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