LT40 Blade guide alignment problem?

[AdamT]

This past Saturday I started making some wavy lumber. Changed out blades, few cuts later, same problem. I get my mill home and start going through the alignment procedure. Not finding anything off significantly. The blade is level front to back, and aligned horizontaly according to the manual with the blade guide rollers.


The blade guide arm seems to be the culprit. However I can't figure it out. It's level from side to side above the rails, and again, with the rollers as to the manual states.  When I engage the blade and bring the arm in and out, the blade wants to twist up. This only happens when the arm is closed about 4-6" from full open. I also think theres too much vibration in the blade as its running, especially when the arm is wide open. Why is this happening? How do you guys adjust the blade guide arm? I'm confused with the instructions given in the manual.

Also when the arm is 3/4 to fully closed, the outer roller doesn't spin. Do I have enough downward deflection? How do you adjust that?

I don't know what else it could be. I had to give up working on it for the night, as my frustration level was increasing significantly by the minute!!!

Thanks for your help!!

[Brucer]

Have you been doing the routine alignment or the complete alignment?

The routine alignment kind of trues things up but over time it simply compensates for more fundamental alignment problems. Once in a while you have to go through the complete alignment (which is pretty time consuming) to get everything back to where it should be.

I just had to replace my blade guide rollers so I did the complete alignment when the new rollers were installed. All the minor but irritating alignment issues have disappeared .

[JustinW_NZ]

Follow the book word for word on alignment and i bet it comes right, it sounds like the out guide roller needs to be adjusted / arm is aligned up/down wrong..
The lack of tension causing the roller to spin sounds like a giveaway.

My tens cents anyway.
Cheers
Justin

[Nomad]

     What they said.  Do a complete alignment.  It'll take half a day or so the first time, but it's worth every minute of it.  The guide arm adjustments are pretty  real touchy, but getting them right is important.  I'd say set your mind to spend a morning at it, when you're not tired, and have fun with a challenging learning experience.

[jdtuttle]

I had the same problem & one of my blade guide rollers stopped spinning. If you have one that doesn't spin I would replace them.

[ladylake]

If it spins when set out  and not when set in  the track the guide wheel rides on is not parallel with the blade.   Steve

[BBTom]

Adam, first release the blade pressure and check the guide roller to make sure the bearings are rolling smooth.  If they are, then do the full alignment, if not replace the roller then do the alignment.

[AdamT]

I was following the manual for the routine alignment. Nothing was majorly out of whack as per the specs in the manual, which really makes my head spin

I called Wood-Mizer this morning and he said to hold off on the complete alignment, as the 500 hours on the mill is a little low for such. Just his opinion. He believes the drive belt needs tightening. I don't know offhand when the last time I checked it, but I will tonight when I get home. I'd say its been 50 some hours since last check. The belt and drive feels good going through the log, no squealing like normal when the belt loosens.

I will check into the alignment of the blade guide arm, as I still believe it may be off. And I'll also drop the rollers and get the deflection where it needs to be.

WM said they've heard if the blade twisting before, and he felt strongly it was the drive belt, not the alignment.

Thanks for all your help,hopefully I work it out tonight, even if I pull an all nighter, as both Saturday and Sunday I'm sawing for customers.

[drobertson]

Adam, I was going to say," drive belt tension" seems like I'm always wrong, not sure of your machine, but wave is mostly due to dull blades and drive belt tension, just did mine a few weeks back, real glad I did, amazing  how straight of lumber these mills cut, no one is perfect, but when a mill is set up right they will cut pretty close to it,  hope You get it straightened out, just for a side note, if the moveable guide is an issue, it will cut straight, just give you a parallelogram cant, pretty easy to see, the v rollers are on a cam design, not a hard tweak, just a tweak, they should be good unless a major crash has happened,  just remember to keep a check on the distance from the inside guide to the full open  outside guide, 1/16" high on the outside,  david