Checking Bearings

[WayRiver]

Hi all.

Im new to sawing (for a month been running a used hobby mill (a solid 13 hp 20 foot manual band mill made in Eastern Ontario...company no longer in business))   

Last two logs I cut (one red pine, one white pine) were "wavy".   Second log was cut a couple days after the first log and with a fresh blade.  (resharpened by old owner).

I have been told that I should check my bearings. The shaft for each band wheel is supported on two pillow blocks with bearings.   

Questions:   Is there an easy way to check for bearing wear?  Will a metal straight edge across the band wheels tell me?  (I have one)  Will bearing wear only show up under load....or does it show up when free wheeling?  Is the only way to check the bearings is take them out?

The saw blade appears to be tracking well even under load.  The band wheels don't feel "sloppy".

The mill is set up an hour away at our bush property and not readily available to try things. I need to take all I need to work on it.   

I go back in a couple days and was hoping to go prepared

Comments welcome

[hackberry jake]

I would take the band off and try wiggling the wheels. But my guess is not enough set on your band.

[js2743]

Try a new Blade first, Most all post on here recommends a new blade to begin trouble shooting with wavy cuts.

[york]

Wavey cuts,dull band.am

[bandmiller2]

River,bearings are checked by feel, sound or boath.Remove the band grasp the wheel top and bottom,feel for play[just in the bearing] spin the wheels and listen,and feel for roughness.Good idea when the mill is new or in good shape to feel so you know what play is normal.As the guys have said chances are its the band. Frank C.

[Magicman]

Welcome to the Forestry Forum, WayRiver.   

It is a very high probability that your wavy cuts are being caused by the blade. 

Check your bandwheel bearings as bandmiller2 suggested above.  Under tension, defective bearings probably would be noisy but still not cause wavy cuts.  If they were bad enough to affect the cut, I doubt that they would track.

[Cypressstump]

How are you adjusting the tension on the band ?

[WayRiver]

Thanks for the posts...I will try a new blade and check the bearings tomorrow.

RE tesnioning...There is an outside threaded bolt that applies tension to non drive band wheel. (moves shaft outward between pillow blocks) (not real fancy but seems effective).   Each morning I either put a new blade on or retension the existing blade.  (I let off tension each night if the exisitng blade stays on)

Tension is applied by "feel" (no torque wrench).  Both blade guides are moved away during tensioning and brought back after tensioning and adjusted to clearance and for level. (and width of material I am cutting)

I check tension occassionally during day...

[paul case]

I had some of those same problems when I first started. You said your band was resharpened a log before you noticed the wavy cuts? I had problems with trying to cut too fast. I would try to cut fast enough to make the motor ''work'' a little. That produced wavy cuts especially in logs with any kind of knots or hard/soft spots. Taking your time cutting is worth it if that produces straight cut lumber.
Does your mill have some kind of blade luber on it? I would like to see some pics of that mill. It sounds neat.

Welcome to the FF. PC

[WayRiver]

Got her going...

Bearings were fine.

I did notice that one of the centre supports on one side was not completely on its block (a bit off)...so it would show level across the mill with no carriage on it.  But when the carriage got in that area it would start to deflect until the support hit the block.  And move back up as the carriage moved through the area. (I think I knocked it off the block when I put the red pine log on....it was pretty long and a big load for my little tractor.....I should have winched it on).    I re-blocked and leveled the whole mill.

I put a new blade on and cut great for the rest of the day.

Lesson learned:  I will do a quick dry run with a bubble level on the blade to check for level as the carriage moves through the mill.

Thanks for helpful advice.

(Paul....Yes it has a blade lube gravity feed system (two shutoffs in line) that connects to the blade guide on the drive wheel side.  I will be more conscious of cutting rate.  I will figure out how to post pics )