LumberJocks

Planer cutterhead bearing replacement #1: HELP! Can anyone give me advice on replacing bearings on my planer cutterhead?

  • Advertise with us
Blog entry by lightweightladylefty posted 12-09-2015 10:37 PM 954 reads 0 times favorited 5 comments Add to Favorites Watch
no previous part Part 1 of Planer cutterhead bearing replacement series Part 2: The bearing is removed; what next? »

Last week my planer blew a bearing on the cutterhead. It is a NuMark 12” planer, more than 30 years old. The company went out of business many years ago.

I cannot determine how to remove the cutterhead. Here’s the issue:
1. The cutterhead casting is a single unit.

2. The bearings on either end are smaller than the cutterhead circumference so the cutterhead cannot be pulled out either end.

.

3. From the parts schematic, the cutterhead appears to be one piece (no smaller diameter inside shaft).

I considered attempting to remove the old bearing

and press in a new bearing without removing the cutterhead, but cannot determine how to remove the old bearing. (There doesn’t appear to be any where to get a puller on it.)

Do any of you mechanically-minded LumberJocks have a solution for me?

L/W

-- Jesus is the ONLY reason for ANY season.



5 comments so far

View Julian's profile

Julian

1034 posts in 2152 days


#1 posted 12-09-2015 11:24 PM

The cutterhead looks like it needs to be pressed out. You could try taking a hard piece of wood (smaller than the diameter of the cutter shaft) and set it against the cutterhead. Strike the wood with a mallet or hammer it to see if you can move the cutterhead. Do not strike the cutterhead with the hammer directly.

-- Julian

View lightweightladylefty's profile

lightweightladylefty

3137 posts in 3174 days


#2 posted 12-09-2015 11:42 PM

Julian,

That was my original plan but the cutterhead diameter is larger than the diameter of either housing diameter where the bearings set. The bearing on the drive side is 40mm; the one that needs replaced is 35mm; the cutterhead is 47mm in diameter. There is not a separate housing around either bearing so there is not sufficient room to pull or push the cutterhead through. And from the schematic it appears that the cutterhead is all one piece.

L/W

-- Jesus is the ONLY reason for ANY season.

View Jim Jakosh's profile

Jim Jakosh

17135 posts in 2567 days


#3 posted 12-10-2015 12:22 AM

Is there a snap ring behind that bearing on both sides. The drawing shows something outside the bearing. Might be a dust seal. That thing has open bearings. Not good for a wood cutting machine. But, if it s a snap ring, they will have to be taken out of both sides

From the looks of it, they put in the cutter head and then tapped the bearing in from either side which means you have to take them out the same way. What I think I would do it get a punch 3/16 to 1/4” dia or what ever it takes to hit the inside edge of the bearing and tap it on one side, roll the opening of the head to the other side where you can access that side of the bearing and tap it there, Keep alternating that until it backs out. And, you’ll have to do that on both sides because you cannot push that cutter head into the hole left by the bearing.

If you get them out, put in sealed bearings.

cheers, Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

View lightweightladylefty's profile

lightweightladylefty

3137 posts in 3174 days


#4 posted 12-10-2015 12:35 AM

Jim,

Thanks for your advice. Yes, there are retaining rings on either end. The one on the end where the bearing needs replaced has already been removed. The bearings are shielded. Both shields came off the one that is showing so that’s why it needs replacing. Thanks for your idea on how to remove it.

We also felt that the cutterhead was inserted from the middle and then the bearings were pressed on to either end. It doesn’t seem like a very good way of doing things, but maybe that’s why they went out of business! It has been a pretty good planer for us and we’ve planed many thousands of board feet of lumber with it. I’ve already replaced the bushings on a feed roller and replaced bearings in the motor several years ago. I’m not ready to throw it away just yet!

L/W

-- Jesus is the ONLY reason for ANY season.

View Jim Jakosh's profile

Jim Jakosh

17135 posts in 2567 days


#5 posted 12-13-2015 01:18 PM

Way to go L/W. Usually when they have snap rings in the groove, the bearing is a tap fit instead of a press fit. I’m glad you had the cordless hammer. That is a neat tool to get a wack at things where you can’t get a swing very well. I have never see one before.

Cheers, Jim

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com