MM Bandsaw Blade Wobble

[Steve Milito]

First a gloat, I just picked up a MM bandsaw. It is a delayed Christmas present.

Now the issue. I just spend hours cleaning it up, and setting it up. I installed the 1" blade that they sent with the saw. I got it tracking so that the teeth are just hanging off both wheels. Seems to track well.
The guides are set up so that the rear guides are about 1/16" behind the blade. Everything seems to work well when I spin the wheels by hand.
Yet, when I power it up the blade moves back and forth, to the point that the upper rear guide spins. You can see jump back and forth. What causes this? How do I fix it?

[Tom Veatch]

... I installed the 1" blade that they sent with the saw. I got it tracking so that the teeth are just hanging off both wheels. ...

If I'm reading that correctly, I'm visualizing the blade running right on or hanging over the edge of the wheel. Don't know about the MM, but wheels on my Jet are slightly crowned and the blade is intended to run at or near the center of the wheel. Perhaps that's the problem.

[Steve Milito]

If I'm reading that correctly, I'm visualizing the blade running right on or hanging over the edge of the wheel. Don't know about the MM, but wheels on my Jet are slightly crowned and the blade is intended to run at or near the center of the wheel. Perhaps that's the problem.

MM wheels are flat. I've set the blade as recommended in the manual.

[Jim O'Dell]

So the blade wobbles back toward the thrust bearing, touching it at times making the bearing spin? If that is right, then I'd say it's a blade problem. Only other thing I can think of is a wheel that is moving, but I'd think you'd notice that spinning them by hand as well. Do you have another blade to try? That would be the first thing I'd try. And congrats on the alleged new MM bandsaw. Without pictures, we're just talking about imagined problems, you know that don't you??? :D Jim.

[Jeff Miller]

If I'm reading that correctly, I'm visualizing the blade running right on or hanging over the edge of the wheel. Don't know about the MM, but wheels on my Jet are slightly crowned and the blade is intended to run at or near the center of the wheel. Perhaps that's the problem.


I'd say Tom's right and the Manual is wrong!

It doesn't matter if the wheels are flat or crowned,I do not think it will hurt to try it in the center of the wheels.


JEFF;)

[Jim O'Dell]

No, all MM bandsaws are designed with flat tires and the teeth almost to the bottom of the gullet should ride off the edge of the tire. Small blades can be/should be tracked in the center of the tire.
With crowned tires, the teeth are slightly above the tire, so never touch it. On flat tires, the teeth would dig into the tire, shortening it's life. Follow the manual on this one. Better yet, download the user written manual that is available. It reads a whole lot better! Jim.

[Jeff Miller]

No, all MM bandsaws are designed with flat tires and the teeth almost to the bottom of the gullet should ride off the edge of the tire. Small blades can be/should be tracked in the center of the tire.
With crowned tires, the teeth are slightly above the tire, so never touch it. On flat tires, the teeth would dig into the tire, shortening it's life. Follow the manual on this one. Better yet, download the user written manual that is available. It reads a whole lot better! Jim.


I stand corrected and apologize, thank you for jumping in with that advice Jim:D

Learn something new everyday:D




JEFF;)

[Steve Milito]

So the blade wobbles back toward the thrust bearing, touching it at times making the bearing spin? If that is right, then I'd say it's a blade problem. Only other thing I can think of is a wheel that is moving, but I'd think you'd notice that spinning them by hand as well. Do you have another blade to try? That would be the first thing I'd try. And congrats on the alleged new MM bandsaw. Without pictures, we're just talking about imagined problems, you know that don't you??? :D Jim.

Hope this helps to see the alleged problem. :D

[Brian MacDonald]

I'd say take the blade off and look at the weld. The first blade for my MM16 did the same thing. I found that the blade wasn't straight...a misalignment during welding. I replaced it with a woodslicer and everything's fine. I kept the old blade for cutting scrap....

[Tony Franzen]

Try another blade I also think it was missalinged during the welding. That hapens somtimes so try to change that. Ive traded in the blades that i bought that was like this and got new ones that are Better.

[Jim Becker]

Suspect the blade first... ;) When a blade goes back and forth like that, it could very well be that the loop isn't a "perfect" loop...

[Jim O'Dell]

Hope this helps to see the alleged problem. :D

Awww man, that's nice!! My E16 only dreams of growin' up to a fine young bandsaw like that one day. :D
Like the others said, put a straight edge across the weld on the blade, along the back edge. I bet it will show a gap. Jim.

[Jim Becker]

Hope this helps to see the alleged problem.

Nice angle on that shot, too...looks like a sky-scraper! LOL :D

[Steve Milito]

I took the 1" blade off and inspected it. The weld looks fine. I put it up against a straight edge and it still looks good. I'm not sure what's going on, I'll call MM on Monday. I put a 1/2" blade on. It runs a lot better. I still see a little back and forth shimmering, I don't know how much is normal. Clearly the 1" blade was not running right, as the movement was ~ 1/4".
I can't set the upper guides because they run into the bottom of the blade guard, a problem that did't exist with the 1" blade. It looks like the guides are at the bottom of the bracket; I'll have to look at them later today. Any hints?

I was somewhat concerned because the thing was shipped on it's side, motor down. There was a small amount of motor damage because the base broke loose of the pallet bottom. I can't see any damage to frame, and I checked it with a straight edge.

[Steve Milito]

Nice angle on that shot, too...looks like a sky-scraper! LOL :D

I just grabbed my camera with a wide angle lens and snapped a few shots. I didn't want to belabor it by setting up tripod, lighting, composition, etc.

[Jim O'Dell]

Well, I would let MM know how that carrier delivered the saw. On it's side would be a big NO-NO! As stout as that machine's backbone is, I wouldn't think it would happen, but if it ended up on it's side because it fell, then it is possible the frame is bent. That would be a lot of weight come crashing down, I don't care how strong the frame is. Was this documented with the freight company? Did the driver say anything about it when he opened the back of the truck? Or did you pick it up at the terminal and that's how they brought it out to you? It would have been fine if it was laying down on it's backbone, table up in the air, motor out the side and braced to stay in that position. But that wouldn't have damaged the motor. Was the pallet strapped to the bottom of the base? For the others here with the bigger saws, were your's double palleted, mounted to the base, and shipped upright? That's how my E16 was shipped. Bolted to a small pallet, the that small pallet strapped to a bigger pallet, for a fork lift or pallet jack to get under, using the metal strapping bands to secure them.
Hope I'm wrong, but I'm afraid that the shipper messed up, and didn't tell you, or covered it up. Jim.

[Steve Milito]

Well, I would let MM know how that carrier delivered the saw. On it's side would be a big NO-NO! As stout as that machine's backbone is, I wouldn't think it would happen, but if it ended up on it's side because it fell, then it is possible the frame is bent. That would be a lot of weight come crashing down, I don't care how strong the frame is. Was this documented with the freight company? Did the driver say anything about it when he opened the back of the truck? Or did you pick it up at the terminal and that's how they brought it out to you? It would have been fine if it was laying down on it's backbone, table up in the air, motor out the side and braced to stay in that position. But that wouldn't have damaged the motor. Was the pallet strapped to the bottom of the base? For the others here with the bigger saws, were your's double palleted, mounted to the base, and shipped upright? That's how my E16 was shipped. Bolted to a small pallet, the that small pallet strapped to a bigger pallet, for a fork lift or pallet jack to get under, using the metal strapping bands to secure them.
Hope I'm wrong, but I'm afraid that the shipper messed up, and didn't tell you, or covered it up. Jim.

I'm fairly certain that it left MM on it's side because of the way it was crated.

[Jim O'Dell]

When you call tomorrow, ask them. I hope you're right, and you probably are since you can see the construction of the crate. Jim.

[glenn bradley]

When you call tomorrow, ask them. I hope you're right, and you probably are since you can see the construction of the crate. Jim.

I agree. Confirm that it was shipped correctly. I know that when you pickup direct from Grizzly that you must sign a waiver if you want to haul your BS away in any position other than vertical. Hopefully a moot point and it was shipped correctly.

I'm leaning towards a blade issue as well but if your 1/2" does the dance as well, something's going on. Good luck and keep us posted.

[Ken Fitzgerald]

I don't know about the MM-20 but my MM-16 was shipped vertically. The put the b/s on a pallet and built a frame around the b/s incorporating the pallet into the crate. Then the entire assembly was placed on another pallet and screwed to the 2nd pallet and banded to the 2nd pallet.

[Steve Milito]

I think the lower flywheel is off left to right. I see a bit more blade showing on the left side (looking at it) of the wheel.Yet, I want to call them before I start mucking with the settings.

Anyone have a MM with the new style blade guard? It seems to me that the blade guard interfers with the thrust bearing on all but the largest blades.

[Roy Wall]

I think the lower flywheel is off left to right. I see a bit more blade showing on the left side (looking at it) of the wheel.Yet, I want to call them before I start mucking with the settings.

Anyone have a MM with the new style blade guard? It seems to me that the blade guard interfers with the thrust bearing on all but the largest blades.

Steve -
I have a MM20....

You are correct that it interferes -- kind of a weak point of a very expensive band saw (IMHO). I usually keep the 1" trimaster on it, so the thrust bearing doesn't hit. I've run a 1/2" wide blade on it, but it's been a while - I think I had to run it in the middle of the wheel so the back of the blade could get within a 16th of the back bearing.

A local fix is to use a hack saw or Dremel and cut out about 1/2" of the lower blade guard so you can press the Thrust bearing forward.

Keep us informed on what MM says tomorrow........

[Scott Welliver]

Anyone have a MM with the new style blade guard? It seems to me that the blade guard interfers with the thrust bearing on all but the largest blades.
I have an MM16, but I'm guessing the blade guard issue is the same. I used a dremel to trim the guard so the bearing can move forward further. See the last photo in the following post:
http://www.sawmillcreek.org/showpost.php?p=661701&postcount=51

Congrats on the new saw!

[James Jones]

Steve,

I bought the same saw you did, the MM20. I picked mine up at the dock in Austin from MM. They loaded it in my trailer on it's back and we tied it down for the trip to Huntsville TX. It took 4 of us to get it out of the trailer and into the shop (700+ lbs.). After cleaning the table with mineral sprits and wiping the whole saw down I installed the 1" Lenox Tri master carbide blade with the teeth setting off the edge of the upper and lower wheels. I used a set of digital calipers clamped to the blade with a 5" gap between the points and commenced to tension the blade. They say that for every .001 stretch it puts 6000lbs tension on the blade. I tightened the tension knob to .003 which should have give me 18,000 lbs of tension. I then adjusted the tension another 1/2 thousand which should give me around 19,000 to 20,000lbs tension. I then turned the saw on and there was no movement of the blade on the wheels. It tracked exactly where it was placed before tensioning. I have never had the blade move on the wheels during operation and there is no vibration when the saw is running. I set the guides as specified in the book and have never had any problems with them. Your saw should run like mine. If you open the top door, you can depress the safety switch and run the saw to observe the wheel to check for wobble. You can do both the bottom and top door for this check. Just be sure you are in a safe position and keep your hands away while checking for wobble. I checked mine this way and the wheels ran true. You will be exposed to a turning blade so be very careful. This will tell you if the wheels are moving in and out during rotation or not. Good luck and let us know what you find out.

James Jones

[John Bailey]

I've done a lot of research on bandsaws and I've never heard of one being shipped on it side. I think Jim O'Dell is correct. I'm going to be very surprised if this is the way it left MM. I think that's your problem. I've talked to a guy who hauls bandsaws around for a living and he said he would never even put one on its back, let alone on its side.

John

[Alan Tolchinsky]

I brought home my MM16 on its back and had no problems at all with alignment. With all that metal ,especially in the "spine", I would be surprised if it could get bent during transport. I think you could throw this out of a first story window and it would be o.k. But what do I know! I just hope yours is o.k. and you can start having fun with it.

[Jim O'Dell]

My E16 had the same issue with the thrust bearing not being able to move far enough into the blade to be even close. I also used a Dremel and cut off wheels to enlarge and deepen the notch. I guess the manufacturer doesn't think we do anything but resaw with large blades! :) But it is an easy modification and I couldn't see anything that would be harmed by doing so. I'll PM or email you a link to something Sam Blasco did with his instead of cutting it. Might be something you would want to try. Jim.

[Steve Milito]

I spoke to MM today. They are certain that the blades are bad and are sending two new blades. We also talked about some other minor issues and they were very helpful.

[James Mudler]

I guess the next problem is the table, boy that thing is far from level :p

[Jim O'Dell]

Steve, did MM say how they shipped the saw? Wasn't clear from your post or from the email.
I was going to post the pictures of my before and after, but I have posted them before. Here is the post. Before on the first one, and the after is a couple posts down.
http://www.sawmillcreek.org/showthread.php?t=60383
Hope these help. Jim.

[Mark Singer]

It is probably the blade. Sometimes the weld will cause that.

[John Browne]

I've done a lot of research on bandsaws and I've never heard of one being shipped on it side. I think Jim O'Dell is correct. I'm going to be very surprised if this is the way it left MM. I think that's your problem. I've talked to a guy who hauls bandsaws around for a living and he said he would never even put one on its back, let alone on its side.

John

Seems hard to believe the frame of a 20" saw can handle 20000 lbs of blade tension yet be ruined by its own weight lying on its side...

[Tom Veatch]

Seems hard to believe the frame of a 20" saw can handle 20000 lbs of blade tension yet be ruined by its own weight lying on its side...

Don't confuse tensile stress in the blade (PSI) with force (Lbs). For example, assume a blade (1/2" x .025") is tensioned to 20000PSI, the total vertical force on the wheel axle (neglecting weight of the wheel and blade) is .5 x .025 x 20000 x 2 = 500 pounds.

[Steve Milito]

Steve, did MM say how they shipped the saw? Wasn't clear from your post or from the email.
I was going to post the pictures of my before and after, but I have posted them before. Here is the post. Before on the first one, and the after is a couple posts down.
http://www.sawmillcreek.org/showthread.php?t=60383
Hope these help. Jim.
The saw was shipped lying on its side. There was a block at the top of the machine to hold it level with the base. The base was lag bolted to a pallet. The crate had 3 2x4 's on running across the side that was down to allow for skids to slide under it. Erik at MM said that they where shipped standing up in the past, but they tend to fall over. So they asked the factory to ship them lying on their spines, but they ship them crated as above.


I didn't take pictures of the crated saw. I'm "mission focused" when I unload equipment. I do it alone with a chain hoist. I saw that the BS was breaking loose from the bottom pallet when I was unloading it. Thus, I lowered it to the floor, changed the rigging around, and then immediately hoisted it to the upright position. I truly doubt that the saw was seriously damaged.

[Jim O'Dell]

Thanks for the update Steve. I'm glad it was supposed to ship that way. It's something new. Like I said originally, I felt you were right since you were looking at the shipping crate and how it was built, but I'd never heard this being done before.
Let us know if the replacement blades get rid of the jumping. I'll keep my fingers crossed! Jim.