Woodland Mills HM126 blade alignment

[NCWoodsGuy]

My HM 126 has needed blade alignment several times. What I mean is I've had to realign the driven pulley to keep the blade correctly running on the pulleys.
 I know how to do the alignment, it isn't hard once you understand the mechanics of the adjuster.  I just don't know what happens to make the adjustment necessary.
The first time I had to make the adjustment was after a kind of violent blade break. I understand that, something moved I supposed, or the mill maybe shook hard enough to need realigned.

But several times I've been milling, all good and no issues, stop for the day and remove blade , then next time I put on a blade I have to realign. That's what I don't understand.

I'm thinking I possibly have a bend in the vertical pivot bolt in the adjustment slot. Maybe that bolt, if bent, allows the tensioner T handle to sit in a different position sometimes.

Looking for ideas. 

[Ben Cut-wright]

"blade alignment" in tracking or co-planer alignment? 

Removing one blade and then installing a different blade sometimes requires minor tracking adjustments. Always wise to at least check.

Tracking is dependent on consistent blade strain.

[rusticretreater]

Start with the simple things first.  With the blade off, inspect and wiggle everything.  It could be a tire on the pully is a little damaged from the blade break or something simple like that.

The mechanism for adjusting tension on the mill is sturdy so it is unlikely that it would be bent.  Also the free spinning wheel is adjusted differently from the drive wheel.  The manual has the adjusting procedure if you haven't used it.

You might try a few measurements on where things are when the mill is adjusted and ready to go.  Remeasure when adjustment is needed.  The differences will isolate the location for you.

Also, Woodland Mills has great tech support.  

[NCWoodsGuy]

"blade alignment" in tracking or co-planer alignment?

Removing one blade and then installing a different blade sometimes requires minor tracking adjustments. Always wise to at least check.

Tracking is dependent on consistent blade strain.

I'm taking about blade tracking. So a couple days ago I was cutting fine, removed blade at end of job. Next day put on a different blade and I had to adjust the driven wheel to keep the blade on the wheels.

Belts and bearings are all in very good condition. My torque wrench is fine, that isn't the problem, anyway the torque never has seemed to matter as long as it's close.

I had to go one full turn on the driven wheel adjuster in order to keep the blade on the wheels. Seems like quite a bit of adjustment.

Have had this happen maybe 4 times out of about 60 blade changes.

Never have needed to adjust the more difficult drive end wheel alignment.

[Magicman]

I am quite surprised that there is a difference between blades.  ?? 

[Ben Cut-wright]

Only changing blades should not alter tracking so radically to make the blade track off the wheel, IMO.   Ever recall putting the same blade back on and having a tracking problem?

"4 out of 60" could be a few funky blades.  That should require re-tracking when a  'good blade' is installed though, so I doubt it's blades.  Blades that track bad when other (same-blades) track well should be discarded.    

You may never have know you "didn't need to align the drive side if you haven't checked it"?  An important tidbit that many forget when doing a co-planar alignment is to first place the idle wheel in mid range of its tracking adjustment.  The wheels might be parallel but run in different planes.  This  can allow OK tracking but has the blade running critically close to loss of tracking control. 

[NCWoodsGuy]

I don't recall that this problem ever happened when putting the same blade back on, but I'm not 100% sure.

I'll do a coplanar check, need to find a long straight and light metal bar first. I have a drywall square that comes apart and that may work. I suppose string might even work if done correctly. I also have several lasers that could work.

But I think if I had a coplanarity problem I'd be throwing blades, and I'm not.  Definitely worth checking though.

[DanMc]

When it comes to blade alignment after changing the blade, be aware that there is a depression in the square pulley shaft that the blade alignment bolt slips into.  When changing the blade, if you loosen it too much it is possible to end up with the alignment adjustment bolt to pop out of that depression and significantly change the alignment setting.  This happened to me twice, until I realized what was going on.  One time it was out of the depression and then I heard a pop, when it slid back into the depression, and the alignment changed.

My machine was an early HM126, so in later machines they may have corrected this issue.  I have since upgraded to a WM LT35HD.  I have some very fond memories of learning how to mill on my HM126 machine.  (I still have a lot of learning to go!!!!)

Sorry if this description is a bit vague, this was a number of years ago.

[Paul Q]

NC I have a 2016 HM126 and find that exact same problem it's very seldom I can change a blade and not have to mess with the alignment. I think they have changed the way the tensioner works doubtful anything is broken they just used a wonky arrangement for tensioning the blade. I still have mine and it works good for a hobby sawyer. Like myself 

Paul