Dialing in LT40

[rmack]

I have been very frustrated with my new lt40 for some time, I finally got around to the hands on adjustments I have been hesitant to tackle.

I put on new band wheel belts, modified the guard on the drive wheel side to make it easier to swap belts out without removing band wheel. adjusted the guide rollers, trial and error method to get it just right.

It's not all sorted out yet, but is cutting very nice, very accurate lumber now. the first 6-12 inches of the cut are dead flat, even when I hit big dry douglas fir harder than I should from the butt end. there are still some waves, but whereas they were up to 1/2" before, they are closer to 1/32 than 1/16 now, and that's at least double the previous feed rate.  8)   Is this the best I should expect, or is there something else I need to look for?

another thing, cuts are now being made with a lot less blade tension than I was using before.

the front and rear backstops were both leaning back so I got them adjusted.

I cut about 250 bdft and swapped in a new blade, oddly enough it seems to ride in a different place on the wheels, giving me less clearance between the blade and the guide wheel shoulder than the first blade did... not sure what causes this.



  

  

 

[POSTON WIDEHEAD]

You were removing your band wheel to swap belts?

[rmack]

You were removing your band wheel to swap belts?

no, I just didn't change the belt because I couldn't get it off without taking off the bandwheel because the guard was bent.  :D

[drobertson]

Head scratcher for me, I am thinking they are  little differences from machine to machine?  I hate to hear you have been battling, I have had some issues with electronics in times past.  All that have been corrected, but not on the band tracking or mechanical at all.   This said, I can relate to frustrations, battle through, all mills have their own set of issues, lots that many do not discuss.   Yours I am out of the loop, sorry,  and hang in,  it is fixable, and as you stated, the quality is there for the taking,     david

[POSTON WIDEHEAD]

You were removing your band wheel to swap belts?

no, I just didn't change the belt because I couldn't get it off without taking off the bandwheel because the guard was bent.  :D

Gotcha! 

[backwoods sawyer]

When i first got my mill it had tracking issues.... every band tracked different then the last, changing the bearings on the pivot pin on the idler wheel helped quite abit but what solvled the problem was replacing the main spindle on the drive side and rebuilding and reinforcing the hole that the main spindle had wallered out.
have not had any tracking issues since.

[barbender]

Good for you Bob, I'm glad you finally went after it ;) On the tracking issue, mine rarely shifts unless something else is wrong (or I've grabbed that handle when detensioning the blade :). I had an idler side wheel bearing go out, that made my tracking jump all over. Look for something that could be moving or shifting, also a different blade will sometimes track different, like going to a.055 from an .045.

[5quarter]

Backwoods sawyer is probably right on the money. don't own an LT40, but if your having a tracking issue, it'll likely be somewhere between the shaft, bearings and band belts. also, a little more set in your teeth will often help keep your blades cutting straight in Doug Fir. Glad to hear you're getting the saw tuned in and up to speed.

[JustinW_NZ]

When i first got my mill it had tracking issues.... every band tracked different then the last, changing the bearings on the pivot pin on the idler wheel helped quite abit but what solvled the problem was replacing the main spindle on the drive side and rebuilding and reinforcing the hole that the main spindle had wallered out.
have not had any tracking issues since.

hm that's interesting to note, mine does track a little different when band is changed but not enough ive been concerned as yet.
How many hours before you had that issue on the machine?

Cheers
Justin

[jcbrotz]

I had my non driven bandwheel bearing go bad twice and can say it will make your band track funny even before you here the noise of a bad bearing. Its a double race bearing so there is not much play. I have to assume you checked the guide roller bearings when you had them off for your alignment , but if not one of them may be the culprit also.

[ladylake]

 
I've found some blades that have been sharpened a lot with track a little ahead of new blades and different brand blades might track a little different.  I adjust if they don't track right, takes about 1 minute on my B20.   Steve

[T Welsh]

rmack, If your cuts are at 1/32 to 1/16 you are on the money! Remember this is rough cut lumber and depending on what specie or how and where you have the mill set up will effect the dimensions of the cut through out the length of the log being sawn. The first thing I would do is to go through the sawmill alignment section of your manual and double check each section and verify that it is correct, this will help you understand the mill,its functions and the correct tolerance of each component,many things can effect the performance of these mills,and when things get off track its time to investigate why. I realign my mill each year regardless of weather it needs it or not,by doing this I assure that the mill is in proper working order. Just because the mill is new do not assume that something has not moved from the correct setting.Take some time and read all about the mill,you will better understand the machine if you are familiar with the technical details. Good Luck. Tim     

[rmack]

was feeling like a genius yesterday, feeling kind of dumb now... I didn't think to check the bearings on either band wheel because they only have 73 hours on them. I did notice the fluid was topped right up on the drive side.

I did weld bandsaw blades together back in the 80's, seem to remember it was a bit of an art to getting them together just right... maybe that has something to do with it?

[Magicman]

Normally when a blade breaks, there is metal fatigue throughout the entire blade, and it will soon break somewhere else.  Sometimes we just have to let the dead die.   :-\

[rmack]

Normally when a blade breaks, there is metal fatigue throughout the entire blade, and it will soon break somewhere else.  Sometimes we just have to let the dead die.   :-\

not quite sure what you are talking about  ???

I'm assuming that every blade should track in the same place, if this is an erroneous assumption and the fact is that every blade will track a bit differently, then my problem is solved and I have one less thing to worry about.  ;D

[Magicman]

not quite sure what you are talking about  ???

Just a general statement because sometimes sawyers will try to prolong the inevitable by considering welding broken blades back together.  It won't work.

[rmack]

not quite sure what you are talking about  ???

Just a general statement because sometimes sawyers will try to prolong the inevitable by considering welding broken blades back together.  It won't work.

I was thinking that there could be some slight misalignment at the weld joint that could make blades track differently.

[Magicman]

I have never seen any noticeable difference in tracking with WM blades.  As a side note; I always use WM B57 belts which are flat instead of the auto parts belts which may be crowned.

[rmack]

I just put on new belts from the woodmizer dealer on vancouver island, there are no woodmizer markings on them, the only thing I noticed was all 4 were matched. CE markings

[Magicman]

Getting them from WM assures you of having the correct belts.  That is one variable that you can forget.

[drobertson]

I am close to hesitating on posting again, but have to ask, how can a newer mill be tracking so off?  Just asking, I have had a few close calls as to what might be called ramming, but never an issue with tracking since 05' on my 40.  I suppose it could happen, and glad it has not for me,  good band blades, good wheel belts, and proper alignment pretty much insures trouble free sawing,   david

[Magicman]

Two blades tracking a bit different should not be a sawmill tracking problem.  I would just put a couple more different blades on and see where they go.

[backwoods sawyer]

my mill had almost 5,000 hrs on it when i got it, the idler arm pivot bearings are small bearings and they been bad for sometime when the problem was tracked down and I replaced them, i was talking with a woodmizer rep on the phone and he had told me to increase the band tention (air bag style) from 60 up to 80 with the saw running to see if that changed the tracking, when i got to 70 the saw jumper off.
hope that helps

[Brucer]

A well-used blade will sometimes track a little differently from when it was new. When I'm checking or adjusting my blade tracking, I always use a brand new blade, straight out of the box.

Last month I had a tiny bit of Douglas-Fir bark get wedged between the bottom of the blade guide and the blade on the drive side. D-Fir bark is a bit like cork ( soft and slightly porous). It's got a high coefficient of friction and doesn't draw the heat off. So my blade got really hot. That blade ended up tracking about 3/16" further in front of the bandwheel .

[rmack]

I ran the mill for about 15-20 minutes yesterday, just needed a few small pieces for a shelving project, anyway I just happened to check the clearance today and it is back to where it should be... same blade.

I guess the blade does run a bit different with some use. I will be keeping an eye on this in the future. 

edit; I wonder if it may have something to do with the 1 1/2 x .050 blades going around the smaller diameter bandwheels? I may go back to the 1 1/4 x .045 blades and see what happens, I have a lot more of those ready to use.