Help! Blade Carnage

alecs · May 29, 2022, 03:37:51 PM

Hi,
I put a new blade on this morning and cut up a log with no problems. Mill is a Woodland Mills HM130 Max. Sawing very fresh white pine. 16" diameter. Made a bunch of 1x10" successfully.

At the end, I decided to resaw the first cuts that I made into 1x8 and 1x6s. I made a few pieces one at a time, and then stacked the last three flitches next to each other and started to cut to make 1x6s. Then, KABAM, the blade came off the wheel, the belt came off the wheel, six or seven teeth missing from the blade, and a big kink in the band. Carnage as shown in picture.

So thinking it was a random and inexplicable error, I cleaned up everything, installed a fresh blade, checked the blade tension, belt tension, blade tracking, blade guides and bearings looked good too. Went back to the same cut and had no problems. Flipped the boards over to trim the other side, and KABAM, same exact carnage. You'd be hard pressed to tell the two pictures apart.

At first, I checked all the obvious metal strike locations. No nails in the wood (this log is from 25 feet up in a tree in the woods, plus I double checked there was no metal). No strikes of the log stops or clamps. I couldn't figure it out. Upon closer inspection, it seems that the blade went off the back of the band wheel, got caught between the blade housing and the band wheel, and then jumped back to the other side, which is what dislodged the drive belt.

Not wanting to trash a third blade in a row, I went back to the manual. One of the interesting things it suggested was too much lubrication. I didn't adjust the lubrication between cutting the full 10" wide boards and resawing the 1x. So maybe there was too much lubrication for such a narrow cut and that caused the blade to slip off the wheel? Another possibility was blade tension not being high enough. I set the blade tension with a torque wrench to the recommended specs, so not sure what I did wrong there.

Any recommendations appreciated.

jimbarry · May 29, 2022, 05:26:28 PM

What do you use for lubricating the band?

JoshNZ · May 29, 2022, 05:50:00 PM

I'm sceptical about the over lubing thing myself, I've sawn some nasty species with the diesel dripper turned right up, forgotten to turn it off while loading logs, pulled the throttle with a shower of diesel spray out the exhaust side and never once had any issue with a band slipping off.

My first guess would be that your drive belt is coming off at the engine pulley or tensioner, and dragging your band with it, I assume the drive belt doubles as the band wheel tyre in this model?

alecs · May 29, 2022, 06:01:41 PM

For lube, I am using water mixed with dish soap per the manual.

Yes, the drive belt is the tire.

I went through everything again, adjusted the belt tension, set the spacing on the guide blocks and bearings for the blade, set the blade tension a little higher, and tested the tracking and alignment and all seemed good. Started cutting another log and got through about 10 cuts making slabs and flitches. Went to cut the first slice off the squared up cant, having no issues thus far, and then....KABAM again. This time the blade got stuck between the band wheel and the housing; I had to cut it with tin snips (sorry, tin snips) to get it out of there. I have a spare belt, can try that tomorrow. But I'm making some pretty expensive lumber right now!

btulloh · May 29, 2022, 06:08:42 PM

Make sure the clutch pulley, drive pulley, and drive while are all in line. I think Josh has probably got it right. Most likely suspect to me is the clutch pulley being skewed due to engine mount being a little catywampus.

Wintergreen Mountain · May 29, 2022, 06:17:59 PM

Check the clutch idler pulley ,shaft and bearing. It looks out of alignment in the last picture.

barbender · May 29, 2022, 06:36:58 PM

How is the blade tracking on the wheels?

Southside · May 29, 2022, 06:40:15 PM

Have you tried checking the tracking by turning the wheels by hand with the band on? Sounds like it's walking off the belt which has to be an alignment issue. Probably quite slight since it doesn't happen immediately.

Patrick NC · May 29, 2022, 07:22:28 PM

I cut a bunch of white pine a couple weeks back. Had some issues with the blade popping off when I first started. Pitch and sawdust were building up on the belts and walking the blade off. I switched from water/soap to a diesel drip and no more problems.

Joe Hillmann · May 29, 2022, 07:39:00 PM

Does the back of each belt have a bit of sticky sawdust stuck to them or are they perfectly clean?

My mill throws bands if I put too much lube on clean of all they sawdust and the wheels become slightly wet with lubricant. That could be your problem?

Check your pulleys are perfectly lined up. Can you run it without a blade to make sure the belt doesn't want to jump off on its own?

alecs · May 29, 2022, 08:40:50 PM

I ran the blade by hand and with the engine without cutting, and in both cases the blade tracked true.

The belts are clean of pitch and sawdust. The manual mentions running the blade without lubricant for 30 minutes to dress the belt. I did do that to begin with. The belt is a little chewed up from the three blades I destroyed today. Maybe I should replace the belt and run it dry for a bit?

This morning was the first time I put on a new blade. The mill is new and came with a blade installed. That blade never jumped off but it did get dull after a while so I changed it. I also bought a box of 10 blades and it's the first three of those blades that have jumped.

Will check out the other things in the morning. Thanks for the suggestions.

barbender · May 29, 2022, 09:12:29 PM

I've had bad bandwheel bearings make my blades jump. I know I have one going when my tracking starts to get wonky. It usually stays true and never needs adjustment.

booman · May 29, 2022, 10:30:34 PM

I have never had a blade come off and take the drive belt off also. Something
going on with that drive belt I think.

chet · May 29, 2022, 11:12:10 PM

Change yer drive belt. I had a drive belt a while back that would actually roll right over in the pully groove. I checked tension and alignment and all was good, but the problem persisted. Changed the belt and no more problems. Could very well be what's happening in your case, only your belt flips right off taking the blade with it.

Joe Hillmann · May 30, 2022, 01:19:35 AM

Quote from: alecs on May 29, 2022, 08:40:50 PM
I ran the blade by hand and with the engine without cutting, and in both cases the blade tracked true.

The belts are clean of pitch and sawdust. The manual mentions running the blade without lubricant for 30 minutes to dress the belt. I did do that to begin with. The belt is a little chewed up from the three blades I destroyed today. Maybe I should replace the belt and run it dry for a bit?

This morning was the first time I put on a new blade. The mill is new and came with a blade installed. That blade never jumped off but it did get dull after a while so I changed it. I also bought a box of 10 blades and it's the first three of those blades that have jumped.

Will check out the other things in the morning. Thanks for the suggestions.

On my mill(homemade so may not applicable to yours) there is a sweet spot between the wheels being so clean the blade wants to jump off , and , so much build up it causes problems.
Can you stretch a string line between and across both band wheels to make sure they are close to parallel? As well as between the drive pulley and clutch pulley to make sure they are in line?
Did the blades by chance come off while you were pulling the head back to set up for another cut? I have had blades come off when backing up the head from the blade hitting the end of the log or backing up half way through a cut and the blade binds up in the cut and pulls the blade off.

alecs · May 30, 2022, 09:34:36 AM

Thanks for all the suggestions. I put my level across the two bandwheels and I see that the drive/clutch pulley is set back almost 1/4" from the plane of the bandwheels, which could very well cause the belt to want to take a jump. I emailed Woodland tech support to see what they say. Seems like the engine would need to slide forward to get the drive pulley back in line.

If anyone else has one of these mills, it would be great if you could check this measurement for me to see if it is normal, or if this is indeed the problem.

Thanks

booman · May 30, 2022, 09:53:33 AM

There's your sign.

btulloh · May 30, 2022, 10:02:21 AM

X2. They should have a helpful response. That picture gives them some good info. Something must be off with the motor mount to put the clutch that far back.

Ljohnsaw · May 30, 2022, 05:49:39 PM

If it came from the factory that way, maybe they will make good and send you some new drive belt(s) and bands for the ones that got damaged? :-\

alecs · June 01, 2022, 05:49:00 PM

Well, the tech support from Woodland Mills said that the position of the engine is not adjustable, that the alignment of the pulley was not an issue, and that I should change the drive belt and run the saw with no lube for a while. He thought the issue was too much water causing the blade to "hydroplane" off the belt. Anyway, I tried it out and so far, so good. Will see if it was simply a matter of too much water. thanks for all the suggestions.

Joe Hillmann · June 01, 2022, 06:56:32 PM

Just out of curiosity, who brought up the idea of using too much lube causing the blade to float off the belt?

If he brought it up first, then that is probably a common issue.

If you suggested it first (because of my suggestion) he may have just been trying to come up with an excuse you will accept. I say that because I have no idea how common it is for blades to float off the wheels like mine. I have it happen all the time (on a home made mill) but I have never seen anyone else bring it up as if it were a common problem.

fluidpowerpro · June 01, 2022, 07:20:45 PM

My small Hudson Oscar 18 has the blade running on top of the drive belt and the only issue I have ever had running too much lube (water/soap) is the belt starting to slip. I have never had a blade come off. That's just my experience....

Wlmedley · June 01, 2022, 08:19:52 PM

My Woodland Mills 126 threw the blade a couple times when I first got it.I adjusted the tracking and never had any more trouble.It now has approximately 70 hours on it.I hardly ever use any lube at all except when cutting pine which I don't have much of.I cut mostly poplar and red and white oak.

alecs · June 01, 2022, 08:43:59 PM

Quote from: Joe Hillmann on June 01, 2022, 06:56:32 PM
Just out of curiosity, who brought up the idea of using too much lube causing the blade to float off the belt?

That's listed in the owner's manual troubleshooting guide as a possible cause for the blade coming off.

Joe Hillmann · June 01, 2022, 09:33:46 PM

So it is a legitimate issue. I thought it may only be an issue with mine because I haven't seen other complain about it. In that case I would take their recommendation and give it a try.

On my mill I want the blade mostly clean but I want a tiny bit of build up on the wheels and the wheels to be dry. When the wheels are clean and wet it is nearly a garantee that my blade will come off. I mill mostly pine so pitch is a very large issue for me and I have to be very careful to use enough lube to keep the blade clean but not so much it causes problems.

Usually I get the blade about 6 inches into a cut and while cutting give it a few drops of lube that cleans the blade but by the time I get to the end of my cut the lube is gone and I don't run the risk of the blade coming off. Where it is a real problem is if there is a sappy knot near the end of the cut and I need to clean the blade to keep it cutting straight but need the lube gone by the time I get to the very end of the cut.