I've been having trouble keeping my blade guide rollers rolling!
Earlier this spring I did a complete alignment on the mill, and the blade guide rollers will just stop rolling every once in a while, doesn't matter if the blade is in the wood or not!
The rollers ARE adjusted 1/4 inch lower than the band wheels!
Frustrating enough to ALMOST make me want to put a sign on it and park it next to the road!
Any suggestions welcome!
What condition are the bearings in? Eventually the rollers do wear some, maybe it's time for new ones?
Is the wood cutting strait? if the blade were to dive below the down setting, it could allow the roller to stop (unlikely). any noise with this or galling to indicate a hard stop with the blade sliding over the stalled roller?
I second checking the bearings
Have you turned the rollers by hand with the blade off, or at least untensioned, to see if they roll freely?
The rollers were new last summer, and haven't sawn but about 3,000-4,000 bf.
The rollers don't show any wear, edges are still sharp.
With tension backed off, I can spin the rollers by hand and they'll spin for a couple of seconds!
I loosened the nut holding the rollers on the shaft and that helps some!
It doesn't matter if the blade is in the wood or not.
Kind of odd: I can engage the blade enough to make the blade spin and the rollers seem ok, but if I fully engage the blade, one (outer) and sometimes both rollers will stop.
I'm sawing old Red Pine, it was cut a year ago, sawed some White Pine and Elm (same site) a couple days ago and everything was fine, could it be just the sawdust and pitch of the old Red Pine that's causing the problem?
I've sawn fresh-cut Red Pine before with no issues!
Are you sure the spacer and felt washers are in correctly? It does matter which washer is in front and which in back.
On my sawmill it would not matter how tight the bolt is that holds the roller on. Within reason. I would think that if your rollers are stopping when the blade is spinning that you should see flat spots on the rollers.
I just clean around the rollers removing what sawdust & dirt that has accumulated and go from there.
There are no flat spots, I have been watching the wheels closely.
Next sawday, I'm thinking about using NO WATER, maybe dry the issue will clear up!
I'm also thinking about making a sawdust deflector to prevent sawdust from hitting the outer blade guide roller, making it out of a piece of a 1-quart oil bottle and it will go on the water side of the outer blade guide roller!
If it the guides spin better with the nut loose, I suspect something is trashed in the bearing assembly.
I went through this a month ago, the spacers in my assembly were also worn. I destroyed the blade guide.
I didn't loosen the nuts to the point where you could wiggle the wheel even a little, maybe just 1/8 of a turn, if that!
I'm thinking that maybe the issue started with the dead Red Pine because of the sawdust like crud that was between the bark and the wood.
When a little water was added, it made like a slimy film on the blade, and no friction on the blade guide roller!
Lube shouldn't affect it Chuck, not with the down pressure that you have. I would completely disassemble the roller assembly because something ain't right. Way out but it could even be a seized bearing and the inner race is turning on the shaft.
Lynn, am I correct in thinking the the nut that I loosened is supposed to be tight (real tight) against the inner race on the bearings.
Also, I've never taken a roller apart, are the bearings actually tight to each other, or is there space between them?
There is a space between them, also a spacer / washer depending on which band width you are running, along with two felt "washers" and it matters which one goes on the front and which one on the back.
Chuck, I've got the same amount of down pressure as you, and I've experienced the same phenomenon you describe when sawing red pine and other pitchy woods. Sometimes some of the build up will float around until it comes to that outboard roller, and it will kind of wedge between the blade and roller. The down pressure must keep it from going between the blade and roller, and there is a bit of a "slime" layer that greases things up. Usually if I turn the water off and let it spin for a few seconds, friction increases and the roller will take off again.
Quote from: Chuck White on May 23, 2021, 10:35:45 PM
Lynn, am I correct in thinking the the nut that I loosened is supposed to be tight (real tight) against the inner race on the bearings.
Also, I've never taken a roller apart, are the bearings actually tight to each other, or is there space between them?
Attached is diagram from woodmizer website showing the blade guide assembly from 2001 LT40 super.
If the roller is a greaseable one ("re-lube") then there will be a C-shaped spacer (33) between the two bearings and the bearing sides facing each other will have the rubber seals removed.
if the roller is not regreaseable then there will not be a spacer between the bearings, and both sides of each bearing have rubber seals.
On either side of the roller/bearing assembly there is a felt washer 3 and 6 (gray in front, white in back) and a metal spacer (2) which has its smaller diameter pressing against the inner races of the bearings. So tightening the bolt doesnt affect the ability of the roller to roll. I dont remember for sure that these spacers (2) are also used in the greaseable relube roller assemblies or not (they are not shown in the inset diagram) but I think they would be, otherwise it seems the roller would be pressed against the head of the bolt in back and the nut in front and not turn when tightened.
When changing bearings I remove the circlips and use an automotive socket to drive the old bearings out of the roller from the front side. This is a one time thing as this damages the bearings. When putting in the new bearings you have to use a large enough socket to drive them in so that the socket is pressing on the outer race. It helps if you first heat the empty roller in an oven at 275 F for a half hour and put the bearings in the freezer an hour or so. But you need to work quick as the outer race heats up pretty quick as it is being put in. And dont want to be doing this on the kitchen counter. ::)
(https://forestryforum.com/gallery/albums/userpics/22511/DSCF0070.JPG?easyrotate_cache=1383173456)
Is what I had to do. and then from time to time, I have to clean the dust out from around the roller. What happens is the back of the blade will cut into the back flange.
Have you tried some Pinesol or more Dawn dish soap in the lube? They might help keep the blade cleaner.
Seized up bearings lead to destroyed guides.
(https://forestryforum.com/gallery/albums/userpics/12217/PXL_20210525_012406851.jpg?easyrotate_cache=1621905909)
(https://forestryforum.com/gallery/albums/userpics/12217/PXL_20210525_012256755.jpg?easyrotate_cache=1621905901)
(https://forestryforum.com/gallery/albums/userpics/12217/PXL_20210525_012302393.jpg?easyrotate_cache=1621905898)
How long did you run that for after it stopped turning?
It went from "bad" to "worse" over a few hours.
I was trying to limp it along to finish a job.
I was concerned about it catching on fire....
Long story short, if your guide isn't spinning properly, take the time to properly troubleshoot it.
I use Dawn dish soap in my lube tank, might be I should add more!
Hi
I have the same problem which appears and then disappears. Of course, rollers are set to push the blade down etc.
Maybe it is just my thinking but this happens when too much liquid detergent is mixed with water.
Or too much water is going on the blade and then "aquaplaning" happens.
I agree, it could be just like a car hydroplaning across a water puddle on the highway!
As I noted earlier at slow speed, the roller would turn, but at full speed it wouldn't!
Quote from: Chuck White on May 23, 2021, 10:35:45 PMLynn, am I correct in thinking the the nut that I loosened is supposed to be tight (real tight) against the inner race on the bearings.
Yes, that nut is holding the inner race secure and it should be tight. Your description indicates that you have a seized bearing and when you loosen the nut the inner race in turning on the shaft which is not good. LINK (https://forestryforum.com/board/index.php?topic=50613.msg730965#msg730965)
You have been sawing much too long to suddenly start having lube isues.
Me too, Lynn!
But I've never sawn Red Pine with this much dead stuff between the bark and the wood!
Going to saw today, start out with no lube and see what happens!
Thanks again to all that provided input!
Well, we finished that sawjob today!
No lube, took a little bit of time 1/4 log, then the rollers worked fine.
Really had me pulling my hair out, and wanting to make all kinds of adjustments, but didn't!
Note to all: If you know your mill is all aligned (by the book) and you start having issues, don't start making adjustments!
As I found out other things can affect the cut and performance, it could be a dull blade, feed speed, or as in my case it just seemed to be the lube mixed with the bug & rot dirt between the bark and the wood!
Thanks again for inputs!