Woodmizer vibration in band and the mill is buzzing, help! -- Update

RPowers · February 23, 2014, 10:50:34 PM

There is something off-kilter in my mill and I can't isolate it. I parked it at my house after the last away job, used it to cut a mbf or so, then tarped it and haven't used it for about a month due to other projects and bad weather. I uncovered it and started checking everything a couple days ago in preparation for an upcoming job, and now it is making a loud buzz/hum when the blade is running. It was somewhat of an oscillating noise, and I could see the band flutter with every peak, so I suspected sawdust buildup or guide roller misalignment. So I cleaned the belts, put on a new band, and it still was doing it.

Before this the noisiest thing when the mill was cutting was the engine at high rpms, and that "shick-shick" sound of the guide rollers spinning, now this aweful buzz is the loudest thing. It sounds very similar to those big tree service chippers, and when I throw the clutch lever to shut it off you can hear that buzz "spool down" for lack of a better term. It is in the area of the main drive wheel. I've checked all bearings for play and none seem hot or loose. I did a routine alignment and got everything spot-on to within 1/32". Now the band runs straight as a string except when the outer guide roller is all the way in, then it flutters nonstop. Do I need to put more down-pressure at that position to fix this, or less down-pressure? It is frustrating to throw the guide arm half-to-all the way out and see the band so straight it looks still, and then pull it in and the thing is oscillating. If the drive belt tension is too high what will that cause? And that darned buzz is still there and I can't find it. It actually vibrated a bolt out yesterday, I keep waiting for something to come apart so I can find the source... but I'd rather locate and adjust it before that. The oscillation is bad enough to leave tooth waves on my boards, not wavy cuts, just 1/2" apart chatters about 1/32" deep. The mill was cutting smooth a few weeks ago, and has not been moved at all.

I know with the tens of thousands of combined hours you all have on Woodmizers someone has seen something like this before. Help! :-\

I'm posting this in the WM forum as well for anyone who goes there more often.

JustinW_NZ · February 23, 2014, 11:16:00 PM

Main drive bearing if going to do all sorts of very odd things like you say.

Its not old?

Cheers
Justin

backwoods sawyer · February 24, 2014, 12:39:51 AM

Hope it is not something serious!
However it sounds like a flat spot on a guide roller, ice and crud could have stopped the bearing while milling on your last job and now that it has warmed up it can now spin. A flat spot on the guide roller will buzzzzz, you should be able to see and feel a flat spot,

Peter Drouin · February 24, 2014, 06:48:22 AM

Check the measurement of the guide arm to the bed should be the same all the way out or in. then when you have the mill runing put your hand on the blade covers and the cover on the side . theres a lot vibration the covers will buzz some. your hand will stop it.Maybe this will help?

drobertson · February 24, 2014, 07:11:29 AM

Not sure about the buzzing sound, but the blade guide roller is an easy one, it sounds like your adjustment bolt on one of the v-guide bearings needs tightened back. Mine takes a 15/16" and a 1-1/8, then you will need to ensure the height is right to the bed while moving it in and out. david

Chuck White · February 24, 2014, 07:21:29 AM

A loose nut on one of the blade covers will make a loud vibration noise!

Might check the center throat bolt!

Magicman · February 24, 2014, 07:42:50 AM

Check to be sure that there is not a piece of bark tightly wedged into a groove on one of the guide rollers.

Jim_Rogers · February 24, 2014, 07:46:02 AM

Check for sawdust build up under the blade v-belts for vibration issues.

Jim Rogers

isawlogs · February 24, 2014, 08:11:45 AM

I have a stethoscpe for mechanic work, it has a rod at the end where a DR would have the cup. Get one or use a hardwoos dowel and poke around with it till you find the loudest spot, that will be where the issue is.

Take the blade off your mill and first eleminate the idler wheel bearing, and also you will eleminate the sawdust behind the drive wheel v-belts. Now once the blade is off and you still have the noise, poke around with dowel to your good ear ;) and locate where the noise is coming from .

Vome back and let us know what is the issue . :P

Ga Mtn Man · February 24, 2014, 08:15:48 AM

The one time I've heard a noise similar to what you're describing was when re-installing the blade cover, I missed one of the "shoulders" that the cover rests on and the blade was try cut it's way through it

.

Have you tried a different blade?

Raise the roller guides above the blade and see if the noise goes away.

RPowers · February 24, 2014, 08:45:54 AM

Thanks so much for all the ideas! I have alot of things to check now. I have already pushed on everything that could be loose while the mill was running to see if a cover or something was the source, but it wasn't any of those. I felt around with the blade running and the vibration feels the strongest around the inboard guide roller area. I'll check that for flat spots and re-check everything for bark or dust stuck somewhere. I think I've checked everything at least once already, but I can miss things the more frustrated I get. I'll keep everyone posted on any changes, if just so that others might be able to diagnose the same problem in the future.
Thanks,
RP

Peter Drouin · February 24, 2014, 01:14:09 PM

I did have a new b57 belt have a lump in it would not run right. I put the old one back on and it worked fine.

Brucer · February 25, 2014, 12:26:36 AM

Try Marcel's suggestion and run it without the blade. If the problem persists, it will have something to do with the drive or the drive side bandwheel. If it doesn't, it could be one of the blade guides or the outboard bandwheel. Or it could be something under one of the bandwheel belts (most likely the drive side). Magicman mentioned something wedged under a belt. The other thing I've had a couple of times on both my mills (usually when sawing in the snow) is sawdust buildup in the balancing holes on one of the bandwheels.

If you remove the blade and feel around under the belt, you will find small holes drilled into the bottom of the grove on the bandwheel. They will be scattered around the wheel, and they may occur in clusters. If you feel the hole, no problem. If you feel a lump sticking up above the bottom of the grove, then you've got buildup. I use a cat's paw and a flat bladed screwdriver to scrape and pry it out. When I get down near the surface of the wheel, the stuff caught in the balancing hole usually pops out. If not, I use an awl to dig it out.

While I'm poking around, I have a paint marker handy and I paint a little line on the edge of the bandwheel right next to every balancing hole. That makes it easy to check for the same problem in the future.

The vibration from this buildup is quite serious because you are constantly changing the stresses on the blade, the sawhead, the bandwheels, and the bearings.

bandmiller2 · February 25, 2014, 07:21:40 AM

Not saying this is bro Powers problem but a tooth or two really set too much can setup vibrations and give you a washboard finish. Frank C.

Magicman · February 25, 2014, 08:52:11 AM

I always remove the blade at the end of a days sawing. Without doing so even a loosened blade will trap sawdust between it and the B57 which is hard to remove.

I thoroughly clean the B57 belts after removing a blade. There could also be sawdust under the B57 causing it to bump. I have never had that happen, but it is a possibility.

RPowers · February 25, 2014, 11:19:47 AM

Took off the band and ran the mill with only the drive side spinning... ran perfect, smooth, and quiet. Put the band back on and retensioned and the noise returned with the vibration being strongest on the bolt that holds the inner guide roller on. Took off the band, started checking that roller for flat spots and found that it was not turning true. When I look at it from the side and turn it by hand it is wobbling like a bent car rim. The nut is tight and the bearing feels solid, so I took off the roller and set it on a flat surface to check for warp.... nope, sits nice and flat all around. So now I'm going to check the axle bolt for bends and if that is straight I'm changing out the rollers to see if this one runs out on the other side. What a pain.....!

jcbrotz · February 25, 2014, 11:26:55 AM

Have you checked your idler wheel bearings? I have lost it twice and it sounds like its coming unglued when its bad. You can also run it with the guide roller off to check if its the bearing in it. If you do swap them from side to side you will probably need to do an alignment due to uneven wear on the rollers.

Bandmill Bandit · February 25, 2014, 11:48:12 AM

From experience with my mill you need a set of bearings in the roller on the blade guide arm. with the band off turn the roller slowly in both directions. you will likely feel a rough spot or a more resistance in a spot or 2. It wont seem like much but it is all it takes to get the harmonics going that you describe.

I replaced mine with an EBC R8 2RS with corrosive resistant seals. They are about 12 bucks each from BC Bearing

RPowers · February 25, 2014, 11:54:26 AM

The wobble problem followed that inboard roller. Both bearings on the guide rollers are tight, but the inside roller does not free spin as smoothly as the outside one, so something in the bearing is dragging. It is like the bearing is tilted inside the roller, causing the roller to spin on an eccentric to the bearing axle. But the bearing is still tight, so I don't know what happened. any one know what size bearing it is, and if and auto parts store might have one so I don't have to wait on WM shipping?

Peter Drouin · February 25, 2014, 12:22:13 PM

I would get the parts from WM, That way you know there fit right and when you order the them get 3, One to replace the bad one and two spares. Good luck

isawlogs · February 25, 2014, 12:33:11 PM

If you are talking about the rollers that the blade rides on\under, then yes you can get them at the auto parts or any bearing shop. Take one out and bring it with you they will match the numbers on it.

Bandmill Bandit · February 25, 2014, 02:23:36 PM

check my previous post.

Gives brand name and part number.

A bit priceyer but bett seals

EBC R8 2RS

Ga Mtn Man · February 25, 2014, 02:42:35 PM

Hey BB, can you post a link for those bearings. Having trouble finding them using google.

Bandmill Bandit · February 25, 2014, 03:15:57 PM

See what I can do. I picked em up at BC bearing. Not sure you have them down there but see what I can come up with.

under the bar code on the box are 2 other numbers as follows.

4 51234 678845

DC:20120608

exact copy from the box
searching now

If you put EBC R8 2RS Bearing in the google search line it should show you local suppliers besides ebay and others.

RPowers · February 25, 2014, 07:29:39 PM

Alrighty,

update.

I got the bearing ## from WM, went to the nearest specialty bearing store and got 2, which is a good thing because there are !!!!!----->2 <----- !!!! bearings inside this roller guide, not one. So an FYI, if you buy bearings, get 2. Glad I bought an extra because my mood would really have gone south had I bought one and come all the way home.

Removed the original bearings, cleaned the race, installed new bearings, reinstalled roller. Guess what, still wobbles, not from being loose but from the roller rotating in a different plane than the bearing axle. So I checked the other roller again, still fine. I thought I'd double check again (quadruple check?) by moving switching only the roller guides and none of the other hardware in order to make sure the problem actually follows this roller. It does. If I start to engage the clutch and watch the band start turning that roller I can see that it not only wobbles front to back in reference the mill bed, but also up and down, causing the band flutter I've been seeing.

Question. Does anyone know how a heavy piece of steel can be this deformed spontaneously between uses? I'm starting to think a supernatural curse or something. Everything on the mill is in perfect alignment and tension, but this one roller is somehow out of plane with its bearing race, yet wasn't a few weeks ago when I last used the mill. I'm stumped. If I knew anyone close with a mill I would suspect a practical joke sabotage roller-switch.