Sawmill maintenance – how to’s and tips.

[Bibbyman]

This didn’t fit in the “Mod’s” or “Usefull things”.  So I decided to make a new post of “How to’s and tips on mill maintenance.  Add’m if you’ve got’m. 

The head on a Wood-Mizer mill rolls back and forth on cam roller bearings.  I’ve had replace a couple of bearings on the mills we’ve had earlier because the needle bearings had worn out. 

On this mill,  a 2002 LT40 Super with 2500+ hours on it,  I’ve checked them from time to time and noted wear but …. They were still rollin’ so I didn’t get too worried about the upcoming replacement.   I did have a stock of extra new cam bearings if one did fail.



I don’t know how much wear is too much but it looked like it was time to replace the ones on the top and side so I did that today.  I thought I’d take a few pictures to show how I went about doing it.

It’s not a hard job and only takes a couple of minutes.  Finding the right combination of tools to get into the tight places is somewhat of a challenge.



Start by raising the head so you can work under it.   The weight needs to be taken off the head.  I did this by propping up the cantilever head with a long pry bar.


 
I used a splitting wedge to lift the head off the track but about any thing wedge shaped could be used.  It only takes a little.  I did one side at a time.

The cam bearing number and arrangement on you Wood-Mizer may be different than the ones on our 2002 Super.  But it looks like the cam bearings are the same.  The LT70 takes larger cam bearings and are said to last much longer.

This would be the same method you’d use to check to see if the needle bearings were still working. Of course,  you wouldn’t have to take the cam bearing off,  you can just try rolling the bearing with your fingers.   They should roll smooth and easy. You’ll know right away if they are froze, welded up, or just worn out.   

It's also a good idea from time to time to removed the cam roller covers and move the head back and forth to see if they are rolling nice and smooth.  If one is locked up,  it's time to replace it.

I checked the cam bearings on the bottom side.  There are two.  One showed only slight wear and the other a little more than slight.  I’ll check them again another day.

[John_Haylow]

Bibbyman.
I think this is a good topic and will be of great benefit for a soon to be new sawyer like myself as well as most others here.

I'm sorry that I don't have anything to contribute as of yet but hopefully  I will get there.

John

[WH_Conley]

Sometimes those bearings will just get dry of grease. Pop the front seal out, wash them in gas or solvent. I have a needle that chucks in a grease gun that I use to lube them. Don't imagine that you would notice the jerking that they do on a Super near as much as a regular mill.

[Bibbyman]

BTW, 

Any time you change out the cam bearings,  the head adjustment needs to be checked.  When I checked the blade height after the change,  it was about 1/4" higher.   

The old style cam bearings had grease zerks.

[BBTom]

The cam rollers were replaced on my mill during the platinum service at 2600 hours.

I was told that the groove that wears in them can actually misform the outer race of the needle bearing thereby causing problems.  Mine looked just about like yours, Bibby, if not a bit worse.  Mine are carrying the 42 HP Kubota Diesel, probably a bit heavier than the 25HP electric motor.   

Ilooks like 2500 hours would be a good time to replace them on 40 supers. 

[Bibbyman]

I’ve posted this maintenance procedure a number of years ago but I did a bad thing and linked the pictures to a free photo album.  That free photo album has went away so now the links no longer work.   So I’ll post it here again.

This from a post I made June 9, 2001 (This time with pictures that won’t go away)

We usually watch and maintain our two Wood-Mizer mills pretty good.  But last week Mary noted oil dripping out of our LT40HDG35 Super.  I took a look and the oil was coming out where the oil drain tube connected to the fitting on the engine.  The tube had been smashed against the motor frame.  No big problem.  I'd just drain the oil and cut the tube off a little bit and put it back on and put in new oil.  About half way done and I noted the reason why the tube had been crushed - the motor mount bushings were all squished out.

I got with Wood-Mizer and they sent me out some aluminum bushings.  The part number is 016380 for my mill.  Apparently they have found that the Wisconsin engine is too heavy for the rubber bushings.  At about $12    each, they are not cheep but I'd expect them to last.    Note that these bushings may not be what is listed in your owner's manual - you may have to ask for them.

You may want to keep an eye on your bushings and replace them before they go out and your down until you can get new ones.

If I did this right,  here are some pictures of the bushing swap.  A couple shows how I held the engine up while I changed the bushings out.  Worked out well.



If you can see in the picture well enough,  the rubber bushing has "squished" out and let the motor fall down about 1/4".  Note that the oil drain fitting is resting on the mount frame.



I figured out how to use the mill's own up/down head power to slightly lift the engine off the mounts so they could be replaced.

A 4x4 is placed over the top of the head frame and secured on one end with a load binder. The other side has a smaller load binder attached to the engine. Then the head is lowered and thus the engine weight is removed. Worked well.



Here is a picture of the other side that shows the strap around the engine.



Here are the old rubber bushings that were all beat out.



Here are a set of new bushings ready to install.



Here I'm fine tuning the engine to mount possition so I can slip the new bushing into place.



 

[Bibbyman]

The cam rollers were replaced on my mill during the platinum service at 2600 hours.

I was told that the groove that wears in them can actually misform the outer race of the needle bearing thereby causing problems.  Mine looked just about like yours, Bibby, if not a bit worse.  Mine are carrying the 42 HP Kubota Diesel, probably a bit heavier than the 25HP electric motor.   

Ilooks like 2500 hours would be a good time to replace them on 40 supers. 

BBTom,  how did the professionals at Wood-Mizer go about changing the cam bushing? 

[BBTom]

Just about the same way as you did, Bibby, but they did not bother propping up the outside end of the head. 

Since I was there helping, there was an extra set of hands.  After the nuts were loose, I pryed up the head ( same spot you had the wedge) with a long pry bar while he replaced the rollers.  Please note that we were in a bit of a hurry due to the replacement of the main drive bearing, and Otto wanted to go home and I wanted to get back on the road. 

It was great to get everything taken care of in one day and be back sawing the next.  I only live 4 hours from Indy, which made it possible.  I might note also that I had called Gene on Monday to set up an appointment, and he just happened to have a slot open on Tuesday.  Is that fantastic service or what?

[Bibbyman]

Did they also replace the top side cam rollers too?  If not, maybe that's how they could do it without lifting the head.  Or... maybe I didn't have to.

[BBTom]

Nope,  just the top ones. and checked the rest.  I think there is plenty of clearance because you just have to take the weight off of them and clear the groove worn in them to pull them out.

Oh yea, I learned that when tightening the rocker with the two rollers on 40 supers, don't forget to put the weight of the head on it first, so the rocker is level. 

[Bibbyman]

Oh yea, I learned that when tightening the rocker with the two rollers on 40 supers, don't forget to put the weight of the head on it first, so the rocker is level. 

OH! NO!    I didn't think to do that.    

I guess it'll work to just loosen the bolt and let it find its own level and then retighten it.

Thanks for adding that tip.

[Bibbyman]

If you examine our mill closely you’ll note some scratch marks here and there that look like they were made on purpose.   Well,  they were.   There are about a half dozen on our mill that I made to mark where I started making adjustments.  That way if I go too far or the wrong direction,  I can have a place to start over or judge from to make another adjustment.

[Kelvin]

I've been wondering how many hours people get on a couple of items.

The back up bearings on the blade guides?

The tires?

What other items need to be watched out for besides the head bearings?

[BBTom]

I have one blade guide roller that is almost 1000 hours old and still fine.  I have gone thru two on the other side in that time.  I use the greasable ones, give them one shot every 4 hours on the hour meter and they last a long time.  The roller on the adjustable side seems to take more of a beating from sawyer not moving it far enough out and letting it drag on the cant, or hit the guide, things like that.  I rebuild mine with new bearings that I get from BDI.  I just pop off the inside seal when installing them and make certain not to lose the very thin washer that has a slot cut in it that is between the two bearings.  It allows the grease to get into the bearings.

Used one of my spares to replace the brushes in a friends 40 hyd just yesterday, he says he has 2600 hours on it.  I better order another set of brushes for mine.  Knowing my luck they will both die the same day.

I replace the blade tires when they need it, never really kept track of hour meter readings on them.

[sparks]

Here's one we get a lot of questions on. Refilling the blade tensioner. I've attached a document with instructions.

[jpgreen]

Bibby-

Are those aluminum bushings Woodmizer?

[Bibbyman]

Bibby-

Are those aluminum bushings Woodmizer?

Yep.

[woodmills1]

my roller bearings used to need frequent replacement, mill is 93, but the newer black ones seem to last much longer.  Yes, when you do replace the rollers readjust the height.  I also once had to recheck the drive chain placement on the roller it goes over under.   Have done most motor brushes also by now.  My blade guides are still doin it every day with a shot of grease first thing and at lunch.  Maybe I should do a hydraulic oil flush its been since like 95 when I broke a velocity fuse.

[Grawulf]

Guys,
This would seem like a good place to ask.............for you that have hydraulics, how often do you change out fluid and filter?

[Bibbyman]

Have you ever watched Norm Abram do his New Yankee Workshop show on HGTV?  If you have you’ll note that every time he makes some kind of frame he will say “Now we have to check it for square.”  And then he’ll measure from corner to corner and announce “That’s perfect.”   Ain’t that something?  Every thing he builds is perfectly square every time.

Well,  we’ve got 2600 hours plus on our 2002 Wood-Mizer and I have to say,  I’ve never ran through the adjustment and alignment procedure once.  I have twinked it here and there as I seen that it needed it.  And I’ve checked some critical alignments after I’ve changed out some components – like blade guides, etc.

After I changed out the cam rollers last weekend,  I checked the blade for level and height above the bed.  I found it needed a little change in height and thought it could use a little tip in angle. 

I made the change in height and did some sawing.  It was close and twinked it a little bit a couple of times until I was happy with it.  At all times it was close enough for the rough farm lumber we were sawing.   But I was still not happy with the level.  I could see it needed to be tipped down just the slightest little bit.

Wednesday morning I adjusted the head angle just a very little bit.  We were sawing cedar and it was a good opportunity to zone in on the fine tuning. 

Here are a couple of things I do to check to see that the mill is in good adjustment.  This has become almost second nature to watch these points to see that everything is running right.



When I turn the cant 180,  I like to come back to that blade height or just a bit higher and glide the blade over the top of the cant.  It should be parallel to the top of the cant.  If the blade is not sawing level with the bed,  it will show up here as the error will be double.





I also check the first and last board off the squared down cant to see if they’re the right width and thickness.   I check the thickness on both sides of the board.  As I was making 1-1/4” x 6” deck boards,  this one was perfect – as Norm would say.

These methods of checking the mill accuracy will only work if you have a blade that’s sharp and set right and a log that’s free of stress.  You’ll also have to take care that you have the cant clamped down tight to the bed and have no bark, etc. under it.