iDRY Vacuum Kilns

Sponsors:

LT40 Tracks and Rollers Issues

Started by deadfall, July 05, 2015, 12:21:02 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

deadfall

Two and a half years ago, I bought a 34HP diesel LT40HD from a professional custom sawyer for about 80% of the new price.  He had two Wood-Mizers and was selling the newer one and saying he was retiring to go into micro-brewing.  I should have guessed he was unloading a problem, as he was first and foremost, a businessman.  The demo he gave me was with small cedar logs where the feed rate was fast and the carriage could just fly through the cuts.  As soon as I had to deal with large logs and cants, it was noticeable that there was some issue, and it's taken me this long to diagnose what possibly could be amiss. 

When sawing larger cants, there is a place along the pass where the carriage hits a wall at the slower speeds, and I have to either crank up the feed rate rheostat, or physically lean hard into the carriage and push it past the bad spot.  I generally use the physical approach, as when I crank the rheostat, once it has the electrical pull to break through the bind, it will lurch forward and go faster than is wise for a wide cut, and risks a wavy cant.  Something I really want to avoid. 

I initially suspected there was a damaged link in the feed chain, and have soaked it in diesel and lubed it with ATF and grease, worked all the links and chain rollers until it was good and limber.  About the time I was thinking of replacing the chain, I realized it is not the chain.  I started looking closely at the upper track, and there is a noticeable difference in the track in the area where the carriage stalls under a load at slower speeds.  There is no paint on the track there anywhere, while the rest of the track has paint where the rollers don't touch.  I started looking very closely at the wear line on top of the track, and while it's about an eighth of an inch wide along the rest of the track, for about 23 inches of the track, where the stalling happens, the flat of the wear pattern there is about three sixteenths over that stretch. 

The man I bought the mill from made a bit of a show about keeping if tarped and the tracks and deck covered, and told me to be sure to keep the track greased.  I look back at that now and see it as a 'tell.'  What the physical evidence shows me is this: that approximate 23 inches of differently worn track where all the orange paint is gone from the entire track is precisely the same 23 inches where the felt track oiler/cover is over the track when the carriage is parked for transport.  The track shows evidence of pitting, though it was probably sanded after the rust damage happened.  Other issues I have had with this mill have been the failures of the main and hydraulic solenoid switches, which both have had to be replaces due to failure by way of internal extensive corrosion. 

So, my theory is becoming this: After the rail rusted under a wet felt oiler for some extended and damaging period, and the mill began being used again, the track cam bearing rollers polished and wore away the rust damaged surface where the felt oiler had sat.  I have spanned a straightedge across the 23 inches and there is a gap where the top of the track drops a few thousands of an inch.  I took the covers off of the upper track rollers and have observed the rollers as the carriage moves along.  The first highly noticeable thing is, the rearmost roller does not turn at all, and is not in contact with the track.  On close inspection of all the track cam bearing rollers, they are all showing considerable uneven deforming. 

I'd say there has been a battle going on between the rust damaged track and the wheels of the rollers for some time, and all these parts have suffered damage.  That rearmost roller isn't frozen, just not in contact with the track. All the rollers are grooved in their centers.  I suspect some degree of center wear and grooving is to be expected. But what I have here might be too extreme. 

I feel one thing I might do is replace all the track cam bearing rollers immediately.  Whether this can solve the problem with the feed rate stalling I can't say, but I suspect it couldn't hurt, except the life of the new roller wheels could be fairly short, because of the damage still existing with the top of the rail. 

So, after this long-winded intro, does anyone here have similar experiences... are there Wood-Mizer company techs who are on top of this kind of issue and can advise?

While the individual who sold me this mill might have produced a good product for his customers,  his let-the-buyer-beware approach to honestly presenting what he sold to me, is something I have come to hate in what I generally term, 'businessmen.'  They are not all bad, but there are plenty of these folks who can give them all a bad name.  What he did was nothing short of the old trick of filling the failing differential of a car with sawdust to get it sold at a price that should have deducted the cost of the repair.  It shows no respect for the buyer as a fellow human, and the greedy desire to play an honest person as the sucker.  There has to be special place in Hell, or a balancing of karma, for such businessmen.

Sorry for the vent.  Thank you for any answers.  There are probably more answers for the technical/mechanical issues than for the personal ones. 
W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

millwright

Welcome to the forum. I would replace the rollers, a few thousands difference shouldn't cause the problem you have, good luck

deadfall

Thanks, millwright.


I am trying to figure out how to post some images here. 


Where the felt cover sits when the carriage is parked:


Where the wear pattern widens:


Where the wear pattern narrows.

W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

Dave Shepard

Welcome to the Forum!

I'm sorry to hear you are having trouble. There are a lot of questions in this case, and it will be hard to fully diagnose over the internet. If the deviation is only a few thousands, as you say, then I don't think it's an issue. If it's more, then that's a big problem. I suspect it may be more. I think one place to start is replacing any, or even all, of the track rollers. If they are not turning, are seized, or out of round, that is going to cause trouble diagnosing. I would also move the head until it stops and check the stops on the bottom rail to see that they are not hitting the rail. These are adjustable, and the spacing does vary as the head moves along the track. If they are adjusted too tight, they might be ok at one spot on the rail, but bottoming out in the bad part of your track. The damage in the pictures doesn't look bad enough alone to be causing the binding alone. I suspect the bad rollers and those stops being out of alignment are causing the trouble. With the head moving freely, you can check the blade height at different bed sections to see how much, if at all, the head is deviating at the bad spot.

The head stalling symptom can also be a bad feed speed potentiometer, which can have dead spots, but I think for now the focus should be the bearings and adjustments.
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

uler3161

From the picture it looks like it happens about where the axle is? Both LT40s (both older models) I've ran have a tendency to stall a bit at that point. And that's with all the leveling legs down and blocks under the wheels. Also that's with new track rollers on one of the mills (If I recall, it had the problem before I put the rollers on too). My gut says this is the same problem, but it's hard to tell just from a photo and description.

I usually do what you do, just bump the speed up a bit, then back down pretty quickly. I don't seem to have much of a wavy cut issue though.
1989 LT40HD, WoodMaster 718

Dan

4x4American

Did you try to turn the mill off and push the head by hand from the front to the back and feel how it binds up?
Boy, back in my day..

Dave Shepard

That's a good idea, too.

There should be no grabbing or stalling. If there is, then there is a problem. I will look up the name of those stops. I think they are supposed to be 1/8" off the bottom rail.
Wood-Mizer LT40HDD51-WR Wireless, Kubota L48, Honda Rincon 650, TJ208 G-S, and a 60"LogRite!

MartyParsons

Hello.
   I would start with replacing the cam bearing that ride on the upper and lower rail. I am not sure you need to replace them all as a set. ( there are many owners that just replace them all as a maintenance measure) If the bearings are apple cored or have flat spots on them from stalling and still being used then replace these for sure.
   If the saw head is binding it makes it easier to remove the forward feed chain or even just the belt for the forward feed motor and push the saw head along the track. When doing this watch listen and feel if there is anything abnormal. If you remove the chain and test then reinstall and have issues you could also have a bearing in the power feed shaft out. The saw head should move with out much effort. Review the manual and check how to adjust before, or ask here about adjustments.
   I have seen a few rails look as your picture. I just take a wire brush to it and shine it up. The wire brush is on a 4" grinder. I would guess it would be road salt or just from sitting out side like you said with a wet felt. This would be for a long period of time and would not happen over night.
   Also remember to have the mill set up with weight on the 6 legs evenly and common sense level. I see many mills out in the field leaning, sunk in the mud etc. I always address this first before any alignment is done.
   The 34 hp Diesel is a good engine. Solenoids like you talked about do not like moisture and should be cycled a little more then they are. Sometimes a cover on the mill creates more issues, it kind of becomes a tropical rain forest under the tarp. Hot during the day and cool at night. I seen a mill last year that was two years old with less than 50 hours on the mill. They used it then parked it in the woods with a tight cover on it. Came back TWO years later and could not understand why the mill would not work.  It was so bad I had to bring it to the shop for repair.

I hope this helps.
Marty
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

Brucer

My LT40 has the same pattern of missing paint in the same spot (about where I park the head). So did my previous LT40. I bought both mills new and saw the pattern of wear developing right at the start. I never did figure out what caused it.

I never had a problem with either mill "sticking" at that spot (current mill has 2500 hours on it). However, before I bought my first mill, I was sawing for a guy who owned an LT40 with a 12' extension (which is just the center portion of an LT40 frame). We had exactly the problem you describe on the extension, at exactly the same spot (close to where the axle would mount -- if it had one). The owner said he'd always had that problem. We figured there might have been some distortion caused when the axle mounting brackets were welded on.



Bruce    LT40HDG28 bandsaw
"Complex problems have simple, easy to understand wrong answers."

drobertson

Yea it sounds like check a cam follower bearing issue to me, find the bad one and would not hurt to check the rail guide for signs of a bend.  It could've been hit, bent, any number of external causes for such a thing.  I will say, it sounds like a potentially easy relatively low cost fix.  A good going over, head to toe sounds in order at this point.
only have a few chain saws I'm not suppose to use, but will at times, one dog Dolly, pretty good dog, just not sure what for yet,  working on getting the gardening back in order, and kinda thinking on maybe a small bbq bizz,  thinking about it,

petefrom bearswamp

Are you walking or riding on a seat.
My old mill with the seat would wear the seat bearings out in a fairly short time and catch on the tire when worn and stick the carriage momentarily.
This happened 2 times in the six years I had the mill.
My first lt40 HD was outside when I bought it and under cover since.
My present mill has sat outside for a total of maybe 10 hrs when at my home pressure washing.
Kubota 8540 tractor, FEL bucket and forks, Farmi winch
Kubota 900 RTV
Polaris 570 Sportsman ATV
3 Huskies 1 gas Echo 1 cordless Echo vintage Homelite super xl12
57 acres of woodland

deadfall

Thanks everyone.  The holiday weekend company is gone and maybe we get back to work, eh? 

I'm in the middle of l pretty big saw job that has to be done yesterday.  With the a mystery fuse blow, the solenoids, and the original battery going out in succession, I don't need other things slowing me down at the moment.  This issue really got in my head because there are a lot of big cants being split and requiring some 20+ inch cuts in Douglas fir, and the lumber needs to be top quality.

No, I don't ride a chair. I walk.

If "apple cored" means the roller wheels are worn in the centers, they are.  The wear is not a clean even line.  It looks kind of galled. 

This mill had 1700 hours on it when I got it and has had this stalling issue from day one when using slow feed rates.  When that spot comes, it just stops moving.  It can be moved past that spot with a good hard push, or turning the rheostat way up to what would be scary anywhere else along that pass in a wide cant.  This is why I choose to just push it past the bad spot.  It has tripped the breaker at that spot a couple times when I didn't apply the push soon enough and the motor drew too much current for too long.  But I really have to lean my light and skinny 68 year old bones into it.   I had an LT30 with the winch when I was half this age, and that was some work.

Today I will stick my head under and look at the lower rail and rollers.  Anyone know what all seven rollers would cost and how difficult they are to replace out in the field? 

If I saw boards without doubling or tripling the cants, I can run without this issue, and am okay to do it that way just to get through this job and make good straight boards.  If the cut isn't multiplying the resistance of the cut to carriage motion, you cannot tell there is a problem.  But as it is, the problem strikes just when you don't need it, when any issue with feed rate can mess up many boards at once.  Smooth and steady, in my experience, makes everything good (except in spruce knots--nothing I have found for that).

Well thanks again.  Time for me to get moving before it gets hot out there.  We're not used to that here in the coastal hills of Washington.  The drought has made it up here from Cali.
W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

Seaman

I am not a WM guy yet, but I will throw a brick at this.

Does it only happen when there is a lot of weight on the deck? I wonder if a heavy load could be flexing the machine over the axles, either up or down? I would use a string or laser level along the entire length of the run and look for deviation.

Just a thought from outside the box. Best of luck, I hope the fix is cheap and fast !
FRank
Lucas dedicated slabber
Woodmizer LT40HD
John Deere 5310 W/ FEL
Semper Fi

deadfall

It's sitting nice and solid and there seems to be no flex.  The sticking happens with the deck empty if I try to take a pass at low speed.  Same as when it's cutting.  It's more the speed, as it is something I can go through fast, there is only a slight slowdown at that spot. 

I crawled under for a look before I started sawing today and the bottom rollers look like new. The clearance at the bolts is very close to the rail but I can't see where they ever touch it.

This show is a bunch of cants and logs that were simply squared up for moving to a distant location a year and a half ago.  They were parked on crib timbers and had tarps screwed to them.  The move never happened and they have some checking started and must be dealt with now.  The ends were well painted so there is minimal checking on the ends.  When the guy who tarped them took out the screws, he broke some of them off.  I have learned he didn't mark them all for the broken screws (don't ya love it?).   

The good news is, I have made the last of the wide cuts this morning and it's just a bunch of four-by, six-by, eight-by, and twelve-by cants now.  After I dig out several broken screws, I should be able to get into some production and get this done fairly soon.

I will be replacing all five of the upper rollers soon.  I will welcome any tips from those who have done that. 

Howdy, Seaman Frank.  I was a submariner (pronounced: submareener) on an old diesel boat in another lifetime.  After that I was a brick layer, so watch out where you toss those bricks. 
W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

Delawhere Jack

Deadfall, welcome to the FF.

Try Marty's suggestions, he knows these mills like the back of his hand. Some minor pitting on the rails shouldn't be an issue. Did you get the owners manual with the mill? If not, get one from WM, and register your mill. WM even keeps records of parts ordered for each mill by serial number, which can be very helpful.

When you've got the manual, read the section on adjusting the track bearings.....then read it again.... and one more time just to be sure.  ;) It can get a little confusing, but remember to adjust the front and rear sets together in small increments. You don't want to adjust the front (or back) all the way to spec, and find the other side is now way off.

Parts from WM are very reasonable, and they have knowledgeable techs taking support calls. You won't be pulling your hair out dealing with some yahoo on the phone.

Changing the lower inboard support bearing can be done with the head parked for travel. The upper bearing require taking the weigh off of them by lifting the head with a couple jacks. There is a thread somewhere in this section of the forum with pictures showing how it's done. Search LT40 track bearings.

Welcome, and happy milling.




Chuck White

Could be 3 or 4 links (in that area) in the feed chain are rusted together or bent and having a hard time getting through the feed sprockets!
~Chuck~  Cooks Cat Claw sharpener and single tooth setter.  2018 Chevy Silverado and 2021 Subaru Ascent.
With basic mechanical skills and the ability to read you can maintain a Woodmizer  LT40!

Delawhere Jack

Chuck, I meant to mention that also, but I got tired of typing... :D

Seaman

Welcome Deadfall !
I always wondered about Underwater Boat People, I am a Marine myself. A few in my before life used to " lock out " of subs, and I thought that was a little crazier than staying inside!
You will find a lot of help here.
Frank
Lucas dedicated slabber
Woodmizer LT40HD
John Deere 5310 W/ FEL
Semper Fi

MartyParsons

Hello!
the bearings 012797 are $ 34.29 each.  You can replace them in the field with no issues. I just had a customer remove both lower brackets - - - -at the same time,  And yes the mill head fell.  :o  On the ground - - - with a big bang!. He said he was not thinking! ? No worries he was not hurt. He had to make a few trips to the machine shop but all is well now.   I asked him " You did what? "  :o
Any way remove one lower bearing assembly replace the bearing and reinstall. You can support the saw head at the rest pin hole with a cant hook or a post. This will help keep the saw head in position. I like to have the saw head forward if a walk mill and rear if a command control mill. Be away from the axle. If you put it on the rest pin you will have issues with the axle being in the way.

The 1/2"  bolts that go into the lower rail are only for transport. They should not be rubbing the rail I usually leave a 1/8" gap.
The top bearings replace one at a time. Use a pry bar to remove the weight from the bearing then remove the bearing and replace with new in one motion.
If you check the alignment before and after you can tell how much it moved. I all depends how much the bearings are worn.
The hydraulic contact block will change with replacing the bearings. Check and readjust.

I think you should remove the power feed belt and push the head where it gets tight and see why. You should be able to see what is binding or hitting causing the issue.

Hope this helps.

Marty
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

Kbeitz

I would put a rolling mic on the track ofrf the carrage to see if you have warpage or a thickness change.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

deadfall

I went over your earlier post, Marty.  I got confused when I read it the first time, about dropping the chain to manually push the head.  Now I get it.

Like I said earlier today, the lower rollers look new.  The rail contact line is smooth on the bottom rail.  I think we can assume the trouble isn't there and I won't be letting the head topple over any time soon. 

=========================

I just went out and took the covers off both top rollers and ran the head the length of the tracks while observing.  The top side rollers, while having some slight visible wear, roll along nicely.  The three rollers on top are a different story altogether.  Only the forward of the two rear rollers turns, and it rolls for the full length of the rail.  The forward roller doesn't turn anywhere except at the far end of the rail (where the rail has the least wear), and then, only a few degrees before it locks when the direction of the head is reversed.  The one top roller of the three that does roll is the one in the best condition, and by the fact that it is the only one with no paint on its threads, and wrench marks on its locking nut, it is obviously a replacement.  The other two have never been moved and are originals.  There is unscratched paint on the threads and locking nuts.

So, I think I will try replacing the two rollers that aren't turning. 

No wonder the guy said to grease the rails.  Those two are skids.  They are no longer rollers.

========================

QuoteAnd ? The suspense is killing me.

Sorry Marty. 

I hit post because I wasn't sure when this login might time out and lose my post. 
W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

MartyParsons

QuoteI just went out and took the covers off both top rollers and ran the head the length of the tracks while observing.
And ? The suspense is killing me.
M
"A pessimist sees difficulty in every opportunity; an optimist sees opportunity in every difficulty." -Winston Churchill

deadfall

Just a bump for Marty, as I was editing when he posted. 

And thank you, Marty.
W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

drobertson

Marty just nailed it, and this is no surprise,  a while back I had the same issues, and it seems that some bearings just last longer than others.  One at a time and the crow bar is the quick trick.  Just don't forget to set at 12" and re-calibrate the set works to set head at 12" and save! after you get the blade height set and on the money, +1/16" high  full open on the moveable blade guide.
only have a few chain saws I'm not suppose to use, but will at times, one dog Dolly, pretty good dog, just not sure what for yet,  working on getting the gardening back in order, and kinda thinking on maybe a small bbq bizz,  thinking about it,

deadfall

Quote from: Delawhere Jack on July 06, 2015, 06:27:14 PM
When you've got the manual, read the section on adjusting the track bearings.....then read it again.... and one more time just to be sure.  ;) It can get a little confusing, but remember to adjust the front and rear sets together in small increments. You don't want to adjust the front (or back) all the way to spec, and find the other side is now way off.

I have a manual and two new bearings are on order.  I may be counting on you all for some guidance, as I'm not the best RTFM guy in the world.

Today I pinpointed the spot where the head stalls.  It is exactly where the up/down chain aligns with the inboard outrigger.  It's where the back pair of rollers are just hitting the rusted and widened stretch of rail wear, and as the forward roller is hitting the end of that stretch. 

I've been on the phone with James at W-M Portland who was very helpful.  Along with several other questions I had about this mill, he was able to see an indication in the parts orders of the previous owner that this mill, though owned by a custom sawing business, apparently sat still for a good stretch in its previous life.  James said the pictures showed rusting he'd only seen in mills from the ocean shore area (they don't salt the roads here).   Since it wasn't from the coast, it was probably just a long time with that felt being wet.  We often get over 120 inches a year here.   Not quite that much where this mill use to be, but he didn't have any indoor storage for either of his two mills.

So, most of my bigger issues have been corrosion related.  A starter, two solenoids, and this.  I bought a brand new, previous year's model, tractor from a lot at the coast and its starter failed from corrosion only a few weeks in.  Sea air is wicked.  The loader joystick on that tractor had to be rebuilt for corrosion too.  That tractor upon arrival here, got its own carport from Costco.  Now let's get that shop built for the mill!
W-M LT40HD -- Siding Attachment -- Lathe-Mizer -- Ancient PTO Buzz Saw

============================

Happy for no reason.

Thank You Sponsors!