Minimax MM20 upper bearings

[Brian Holcombe]

This saw is actually pretty quiet now, I have wondered why this saw is so loud for the entire time I have owned it. I’m not sure the bearings were ever very good but glad now to have some better grade bearings in. I’m definitely replacing the lowers now with the hope that it will get quieter still.

[Tom Trees]

Thanks for your replies Erik and Brian.
I believe it was the same bearings I bought, curious to know if the older ones were a tight fit, compared to the new ones.
Sounds like the wheel wasn't sliding off the shaft without a fight.

Cheers for the update
Tom

[Brian Holcombe]

It felt like a .00025” interference fit, so very light but removing the previous bearings they felt about the same. There is positive retention so I’m not particularly concerned there.

[Tom Trees]

Thanks again Brian.
I'll be keeping an eye on this thread, I wonder if the lower wheel will be more difficult.
All the best
Tom

[Erik Loza]

Thanks again Brian.
I'll be keeping an eye on this thread, I wonder if the lower wheel will be more difficult.
All the best
Tom

The lower wheel is about a MILLION times easier.

Erik

[Brian Holcombe]

Good to know, the upper wasn’t bad once I figured out how to get it out of the saw without a puller. If you run the screw all the way before removing the tension handle you can tip the assembly forward after taking the bolts out and lift it out.

Changing the belt to while I’m at it. The belt squeals on startup.

[Brian Holcombe]

Swapped the lower bearings and belt. The lowers were fine so while it was nice to upgrade there is no noticeable improvement.

One of the things that really bugs me about this saw is the belt tensioner, it’s pretty lousy so I plan to replace it. The belt squeal is not from the belt being bad but rather from not enough tension. This is clear when I watch the saw run and the belt flops pretty badly. I can max out the adjuster and the belt still does not have appropriate tension but finally stops flopping wildly and stops squealing.

While I’m at it I think I’ll make some sort of basic isolation between saw body and motor with high durometer rubber abs rubber washers for the bolts.

I suspect there is something to the idea that the wheels should be parallel with one another. I have never checked that but was told to disregard by Sam’s notes. I checked today and they are not parallel. I suspect that aided in the demise of the previous bearings so I think I will attend to that.

[Erik Loza]

The belt squeal is not from the belt being bad but rather from not enough tension. This is clear when I watch the saw run and the belt flops pretty badly. I can max out the adjuster and the belt still does not have appropriate tension but finally stops flopping wildly and stops squealing.

You could get a longer bolt but I never experienced a case where belt remained too slack. Is the new belt too long?.

...While I’m at it I think I’ll make some sort of basic isolation between saw body and motor with high durometer rubber abs rubber washers for the bolts.

I wouldn't do that. You will probably create more issues as far pulley arbor yaw, once the assembly is under tension.

I suspect there is something to the idea that the wheels should be parallel with one another. I have never checked that but was told to disregard by Sam’s notes.

Sam is correct.

...I checked today and they are not parallel. I suspect that aided in the demise of the previous bearings...

Unlikely.

Brian, with all due respect, I think that you are thinking that you need to treat this like a 14" bandsaw. Trust me: You run a much higher risk of getting poor results by trying to out-think this machine. If anything, I would maybe try a shorter belt and see where that gets you. The rest, I just wouldn't worry about. Good luck with it.

Erik

[Edwin Santos]

Swapped the lower bearings and belt. The lowers were fine so while it was nice to upgrade there is no noticeable improvement.

One of the things that really bugs me about this saw is the belt tensioner, it’s pretty lousy so I plan to replace it. The belt squeal is not from the belt being bad but rather from not enough tension. This is clear when I watch the saw run and the belt flops pretty badly. I can max out the adjuster and the belt still does not have appropriate tension but finally stops flopping wildly and stops squealing.

While I’m at it I think I’ll make some sort of basic isolation between saw body and motor with high durometer rubber abs rubber washers for the bolts.

I suspect there is something to the idea that the wheels should be parallel with one another. I have never checked that but was told to disregard by Sam’s notes. I checked today and they are not parallel. I suspect that aided in the demise of the previous bearings so I think I will attend to that.

I have the same experience with the same saw with the same belt issue. I have added tension twice, both times eliminating the start-up squeal. Then after some time, it comes back. My assumption has been that the belt is not a super high quality and is simply stretching. I've just been keeping an eye on it to see if it gets to the point of slipping under load. This has not been the case thus far, so I just consider it a minor annoyance. I figured at some point I would replace the belt and see if my thesis is correct.

I do not know enough to know what you mean by replacing the tension adjuster. Mine is just a long bolt feeding through a welded on block, and the bolt pushes against the motor flange.
Which is better than my other bandsaw where the tensioner is one guy levering the motor up with a pry bar and the other guy tightening the mounting bolts when the belt seems tight enough.

[Brian Holcombe]

You could get a longer bolt but I never experienced a case where belt remained too slack. Is the new belt too long?.

I wouldn't do that. You will probably create more issues as far pulley arbor yaw, once the assembly is under tension.


Sam is correct.


Unlikely.

Brian, with all due respect, I think that you are thinking that you need to treat this like a 14" bandsaw. Trust me: You run a much higher risk of getting poor results by trying to out-think this machine. If anything, I would maybe try a shorter belt and see where that gets you. The rest, I just wouldn't worry about. Good luck with it.

Erik

Ok, perhaps I will remove the isolation ideas but I can’t imagine 1/8” of 80 durometer adding any yaw issues.

The longer bolt isn’t fixing anything, the bolt is plenty long enough it works against the plate at an angle and at some point the angle becomes too extreme. Belt us identical to that which the factory provided. 3VX475 is what I had and have again. Not opposed to putting a shorter belt on.

Please explain your reasoning/logic behind the parallel issue rather than simply writing off my ideas. If my ideas do not have merit, I can certainly accept that but I’d like to understand why you think what you think. My thought is that putting a normal bearing at an angle shortens it’s Life because the bearings are running against the sides of the tracks. I suspect my ideas do have merit since the upper bearings died and the lowers did not.

I took bearings out of the Maka that were still running clean after 40 years of daily use, these died after 6 years of easy use in my one-man shop.

[Tom Trees]

I've only just replaced the bearings in my motor after fitting a new belt to the saw (same brand and size, bought locally, so wondering now if it is OEM or spec)
as well as having the bottom wheel misaligned, this caused a massive vibration issue which toasted them.
Wouldn't have been a problem with the old belt, as there is looooooads of stretch compared with none on the new one, not even sure if I have enough space for the new one
with the hub being so close to the pulley, might need a bit of working streching out (if that's a done thing?)

I assumed that the bottom wheel would be in line with the cabinet, not so with my machine!!!
I found out the hard way this is not the way to go about it SAM_4155.jpg
SAM_4167.jpg

I only uploaded a video yesterday on setting up my saw after doing a bit of work to it.
Having heard reference about a beam for getting coplanar on the wood whisperers channel
I'm guessing that its along the same lines as what he was on about.

Maybe not the same thing, but some useful info I think, as I haven't seen any demonstrations for this.
There is a Rikon guide for the lower wheel that has some info, be interesting to observe if it correlates with what the beam says,
even though its for cambered tires, it might be the same.

https://youtu.be/VQ9dmP9yF8E

[Brian Holcombe]

Tom, thanks for the update. The wheels are now co-planar on mine and this saw sounds a lot happier. I’m going to go out on a limb here and suggest that getting the wheels co-planar had some merit.

This saw sounded like a box of rocks a week or so ago, now with better bearings and a finer degree of tuning it’s starting to sound a little closer to what I expected of a nicer saw.

Frankly, I was expecting whisper quiet given that most nice bandsaw are, I recognize that the steel frame amplifies vibration noise but it has been pretty irksome to have it both be louder than expected and deal with that awful squeal.

[Bill Dufour]

Did it end up the upper and lower bearings were the same size or different?
Bill D

[Brian Holcombe]

They’re the same.

[Joe Calhoon]

Brian,
Getting the upper and lower wheels parallel is just good machine tuning. I have a couple 40 year old books on woodworking machinery maintenance, one US book and the other from the UK. Dated books, but still relevant to a lot of things on modern machines. They both suggest parallel and the US book goes into detail on how to accomplish this. It says to check parallel both left and right using a straight edge and level to make sure they are the same. I believe the level is accounting for any tilt in the upper wheel.

I checked the left side of the Hema and it is right on. I might have to tilt or remove the table to check the right side.
76AE58B3-98C8-4697-95A8-090C789593AA.jpg