WM outer blade guide arm adjustments question

[Jim_Rogers]

So, I'm on this site milling timbers and lumber for a customer.

My blade guide arm keeps sliding back to the log. It won't stay where I set it.

It is very frustrating to be walking off a slab and hear the engine change because the forward motion has stopped because the blade guild arm slid in and is stuck on a knot or the side of the log.
I have tried to adjust the lower "V" rollers to tighten up on the bar but I don't know if this is the solution or not. I thought it was.

Does anyone know if the top "V" rollers are also on a cam bolt? Can these be turned some to tighten up the grip of the rollers onto the bar.

The bar is not sliding between the rollers. I've watched it, the rollers are turning as the guild arm slides into the side of the log.

Does anyone have any advice or a solution to this?

Thanks

Jim Rogers

PS. I thought this happen to me once before, and I solved it by turning the bottom roller bolt to adjust the rollers to squeeze the bar more. But maybe I haven't squeezed the bar enough.
And I have checked my blade level to insure that it is where it's suppose to be and it is making 90° corners on my timbers.

[BBTom]

You are going in the right direction, Jim.  I believe all four rollers are on cam bolts.  You have to be careful to keep things lined up when cranking on them but you do have to have them tight enough to hold the bar from slipping. 

I set my head at 12" and measure the blade height beside the outside roller when arm is all the way in and when all the way out.  They should be the same. 

Now adjust your rollers, and do the same measurements,  the arm should move level all the way in and out.

It takes a thin wrench to tighten the lock nut behind the rollers.  If it isn't tightened the bolt can turn and let the arm loose again.   If you change the in/out position of the rollers, the tilt of the guide roller can change. 

[Dave Shepard]

Jim, I believe all four rollers have cams. On all the WMs I've run, the blade guide arm has required a lot of force to move manually. I'd snug it up using either just the top or just the bottom rollers, although it sounds like you may have run out of adjustment with just the bottom. Adjusting that arm seems to be the most finicky part of alignment.

[Magic Smoke]

All 4 bolts are on cams.
If you look at the head of the bolts you will see a little grind mark on them, this indicates the high-point of the cam. Also, like BB said, it's important to maintain correct alignment, when you adjust the cams you are changing the vertical alignment of the arm, if the arm goes uphill as you move the arm in, you'll lose downward deflection on the blade, moving downhill will push the blade away from the drive-side roller, neither of which is a good thing.

[Jim_Rogers]

Thanks for all your comments and advice.

I will look at the head of my bolts to see if I can see the marks mentioned.

I have taken a good ruler with me to the site to check the blade level with moving the blade guide in and out.
I may have to try and move the two top ones down so that they squeeze the bar a little more.

And of course I will watch my blade level, and hopefully solve this problem.

Jim Rogers

[T Welsh]

Jim, All advise is spot on! they are adjustable and when you get done adjusting to your liking check the blade alignment with the arm fully in and out. you will probably need to adjust the guides afterwards to get it perfect. I just had to do this when I knocked the guide arm with a log while loading a log last week. Tim

[terrifictimbersllc]

My lt40 manual says to adjust the cams being discussed to achieve a firm position and correct tilt of the arm. The issue of the arm rolling too freely would seem instead to be related to it not being tied in to the blade guide motor via the sprocket and chain.  On my mill this is what provides resistance to inward travel.  Are you sure this part is correctly set up?

[jcbrotz]

In my case when this happens it normaly has to do with the guide rollers themselves. Something stuck in them or going bad, or mal-adjusted.

[customsawyer]

Check your blade guide roller you may have some bark behind it. This will cause a binding and the arm will want to go in with the blade.

[pnyberg]

My lt40 manual says to adjust the cams being discussed to achieve a firm position and correct tilt of the arm. The issue of the arm rolling too freely would seem instead to be related to it not being tied in to the blade guide motor via the sprocket and chain.  On my mill this is what provides resistance to inward travel.  Are you sure this part is correctly set up?

On giving this a couple of minutes of thought, it occurs to me that if the arm was not being held firmly enough by the 4 rollers, then it could slide without moving the rollers connected to the chain, sprocket, and motor.  If that's the case, it still comes back to adjusting the rollers, but the in-out drive assembly could be just fine.

--Peter

[Jim_Rogers]

Again thanks for all your comments and advice.

Of course I have looked at it extensively trying to figure out the reason why it keeps sliding in. And I'm sure you can understand that I would have removed the bark had it been there.
I have experienced the slam when something gets behind the roller and slams the arm all the way over until it clears.

I was wondering if the pad under the blade at the roller was too close to the blade and rubbing it.
I thought that might be why the arm is sliding in.
I didn't think it was but I will check it closely tomorrow morning and see. It is possible that the disc got bumped and is rubbing the blade and causing extra friction to drag the roller in.

When the blade is not moving I can move the arm in and out by the switch as it should.
But when the blade is moving the arm hardly moves out at all by the switch which made me think that the v rollers were not tight enough.

I tried to adjust them the other day, but I didn't have a 15/16" open end wrench with me or a 1 1/8" wrench for the cam bolt head.
I looked all over my shop for my 15/16" open end wrench as it wasn't in my tool box. I couldn't find it and I finally when to the local Napa store and bought a new one.

I did adjust it and I tried it, and it didn't seem to make any difference.

So I adjusted it again, and I figure out that I had adjusted it the wrong way the first time. Duh, what a mistake that was.

But it still didn't improve the situation.

I'll probably have to take the cover guard off the in out motor to see the sprocket wheels and such to make sure they are all working ok. And get this thing adjusted up right.

It is frustrating to try and try to get it right and not get it. It slows down production and that can cost you money.

I'll take some pictures if I see something that I should/could show you.

Thanks again.

Jim Rogers

[terrifictimbersllc]

Peter you're right , good thinking . Jim I agree I'll bet that arm adjustment & slamming has cost me more $$ through down time than any other single problem.  In a complete alignment or any time one takes off the guide rollers it is good to recenter the four guide arm cams.

[customsawyer]

Jim I was just offering a suggestion. There are many times when I get in the heat of battle with a log that I over look a simple thing.

[JSR]

Jim, take a look at the chain tension. My arm does this when chain is loose. Watch tightening rollers, to tight and the sheer pin on drive motor sprocket will snap after awhile. Good luck

[gmmills]

 Jim,
      When it comes to adjusting the arm rollers these wrenches are a must. They make a frustrating job a whole lot easier.                                                 

 

[pineywoods]

Bad bearing in the outer guide roller will do that. The moving blade will gradually pull the guide arm in...

[pnyberg]

Jim,
      When it comes to adjusting the arm rollers these wrenches are a must. They make a frustrating job a whole lot easier.                                                 

 

gmmills,

Back in 2005 when you originally posted about these nifty wrenches you helpfully supplied the source and part numbers.  I went back and dug up the info:

Bibbyman,

   No need to go to Sears. Just go to snap-on .com. You can order them on-line. They are called 4 WAY ANGLE HEAD WRENCHES. The Snap-On part numbers are VS30B for the 15/16"and VS36B for the 1 1/8". Just type in the part number in the search box and it will take you right to them. The width of the wrenches is not an issue. Just a little bit wider than the width of the jam nuts.

I ordered one of each about a year ago, and it set me back $128

--Peter

[Dave Shepard]

I've had the little roll pin come out of the shaft on the motor a couple of times as well.

[Jim_Rogers]

The 15/16" wrench I got from Napa was only $18.80.

Jim Rogers

[isawlogs]

 I bent one that I had, works for me.  ;D

[terrifictimbersllc]

Placement of those bolt heads right up there with those of the hydraulic micro switch.  :   :

[coastlogger]

"I ordered one of each about a year ago, and it set me back $128"
Holy hairballs Peter you need to learn about cheap tools, modified tools,welded tools etc.Thats a lot of cash for something thats pretty easy to lose.Id guess if all my tools were SnapOn Id be a technical millionaire.Needless to say I have a few. As it stands I probably could sell them all for oh say $127. I think I do have one snap on wrench somewhere though,must have found it on the road or something. Guess when it comes to tools I like quantity not extreme quality. I do draw the line at garbage sockets with outrageously thick walls tho.

[pnyberg]

Holy hairballs Peter you need to learn about cheap tools, modified tools,welded tools etc.Thats a lot of cash for something thats pretty easy to lose.

I have a hard and fast rule about not making hard and fast rules, but my general opinion about cheap tools is that they're not worth the price.  That being said, I'm not one to spend a lot of money on tools I don't have a good need for either.  I don't have a clear recollection, but if I could have done the adjustment with the pair of large adjustable wrenches I already own, that would have been the end of the story.  Since that didn't work, I apparently decided to get myself some professional level tools.  This seems appropriate, since I'm trying to be a professional here.  These two wrenches represent about 85% of the money I've spent on tools purchased specifically to do maintenance chores on the Wood-Mizer.  Since the machine cost about $30,000, I don't begrudge the expense.

I don't think I'm likely to lose them.

--Peter

[Jim_Rogers]

Well, I may have fixed it.

The first thing I did was to remove the guard over the bracket that holds the electric motor that moves the blade guide arm in and out. This way I could see things better.

The chain did seem a bit loose, probably worn. I tapped the bolt head that the idle pulley is mounted to and slid it up the slot to the top so that it made the chain tighter. That did seem to make it tighter but it still seemed a bit loose. So I loosened the other two bolts that hold that bracket to the mill and slid the whole assembly down a bit. This pushed the drive sprocket a little more into the chain but not enough to make it rub the return side of the chain.



I had to edge a few boards and it seem to be alright but I didn't move it in and out a lot.

Next I loaded up a log to mill and started working on that.

From this angle:



I could see the top inner v pulley and watch it without the guard on. As I was milling I could see the arm start sliding over and that top pulley was not turning. The blade guide arm was sliding in the "V" of the pulley.

I inspected the cam bolts for the four v pulleys and I couldn't see any marks on one of the top ones, but three of the four seemed to show the off set mentioned above.

I loosened the jam nut on the one closest to the throat opening and turned it's cam bolt until I could feel a little resistance and then snugged up the jam nut.

I checked with my combination square the blade teeth, with the arm both open and closed and they seemed ok to me.

I was able to make it work correctly for the rest of the day, as far as I could see.

I suppose I'm going to need a new blade guide arm motor chain sometime soon. I think I replaced it once over the past 18 years, but I'm not 100% sure.

I do remember that a while ago, probably within the last six months that the chain fell off or something like that.

Thanks again for all your advice and comments.

Jim Rogers

[terrifictimbersllc]

From the looks of it your motor assembly bracket is pushed all the way down because the top of its slots look like they are touching the mounting bolts.   I'd say your chain might be stretched to the max and you're not able to tension it any further.