MM 16 Too Tough!

[FRITZ STOOP]

:mad:
I have been trying unsuccessfully to run a 1/4" or worse a 3/16" blade on my near new MiniMax MM16. The blades appear to be positioned and tensioned correctly. I'll cut for a few minutes and WHAM off the wheel they come. I have tried everything I know and can't seem to get them to work. They advertise that they'll run all the way down to 1/8". The last try snapped a Suffolk 3/16" at the weld. The break might have occurred when the momentum folded it up like used christmas wrapping. 1/2" AND UP BLADES RUN LIKE A CHARM.
Any thoughts?

On the up side, I have finally installed my dust collection duct work. Four months after I got the DC unit on site. 2HP JDS. Works sweet. Pictures soon!
:D

[Mac Cambra]

I've run 1/4 blades on my MM16 with no trouble. The thin blades need to be positioned in the center of the tire unlike the wider blades. I did have to adjust the angle of the upper wheel to ensure proper tracking. You just have to experiment with it, manually rotating the wheels with the blade on until it tracks properly. Once you have it set right you are good to go.

[Cliff Rohrabacher]

The wheels may not be co planar.

The fix is to adjust ( as Fritz said) the upper wheel angle.

Co planar is how they should be anyway so this is a good thing that you are being forced to get your saw set up correctly. All your blades and cuts will benefit.

[Alan Tolchinsky]

With all the guides backed off: Are you able to track the blade on the wheels under tension? You should be able to turn the upper wheel by hand and the blade should track correctly and not come off. Then adjust the guides as per usual. If you're doing this, then something else is wrong here.

[FRITZ STOOP]

Thanks guys!
I have tried all those strategies and still have trouble.
I run the wheel by hand and then run it holding the upper microswitch with my thumb so I can test it at speed. It always remains solidly in the middle of the tire when testing.
I used the "shudder" method of tensioning. Maybe I am too tight or too loose. I should get a mechanical tension tester to be certain. It certainly is frustrating not to be using the small blade turning radii.

[John Thompson]

Just curious Fritz.. when you drop those 1/4" and 3/8" blades on.. does the teeth and gullet sit behind the front edge of the guide bearings or run across the bearings surface? That's assuming you have not put the cool block accessory set on the saw made just for the 1/2" and smaller blades.

No further comment from me until that question is answered.

Regards...

Sarge..

[Ken Fitzgerald]

Fritz,

Did you use the tensioning method recommended by Suffolk? They use what IIRC is a softer steel and they have a recommended tensioning method for their blades.

Mini-Max tires are flat IIRC. IIRC there is no crown so IMHO co-planar is less of an issue. Some manufacturers use crowned tires and then co-planar becomes a real issue. On a machine using a crowned tire, if the peak of the two crowns are not co-planar, potentially you could be riding on the up hill or peak of one crown and on the down hill or backside of the other tire and the blades would try to come off. But, you should see that when turning a wheel by hand and watching the blade to see if it is moving on the tires. You would then correct this by changing the angle of the top wheel.

Good luck!

There is no reason that I can think of why a MM-16 shouldn't successfully run a 1/4" or 3/16" blade. I modified the blade guard on mine so the thrust bearing would come forward far enough to engage the smaller blades but still, there isn't any reason they shouldn't run smaller blades on a normal working saw and it is properly setup.

PS I haven't put anything but 1/2" blade on my MM-16 so far but as Sarge mentioned, I did buy the cool blocks for use with smaller blades.

[Pete Bradley]

I'm thinking that the snapped blade might be a clue. Is it possible that you're overtensioning for the size of the band? Proper tension for the 3/16 band may not be much more than a quarter of the tension of your half inch band since the smaller band is both narrower and thinner.

Also, are your tires in decent shape? A narrow band will be more sensitive to grooved tires than a wide one.

Pete

[Robert LaPlaca]

I have run blades as small as 3/16 Timberwolfs on my MM16, setting up narrow blades is really fussy with the euro guides. A previously mentioned, the blade has to run in the center of the wheel. Adjust the blade tracking with the guides out of the way, once you have the tracking OK, then add the guides..

Good luck

[Wilbur Pan]

Putting a crown on the tires will solve your problems.

Coplanar wheels by themselves (i.e., with flat tires) will not solve this issue. What will happen is that if the tires are flat and the wheels coplanar, a narrow blade will track, but it will be very sensitive to changes in wheel position, so that a small change in the tilt of the top wheel can lead to big changes in where the blade wants to track, and it seems that the narrower the blade, the more this will happen.

What a crown will do is take advantage of the fact that if a blade is running under tension on a curved wheel surface, it will try to go to the highest point automatically, which adds stability to blade tracking, and is ideal for helping to stabilize the tracking of a narrow blade.

[Jim Becker]

Putting a crown on the tires will solve your problems.

These Euro saws are not designed to run with crowned wheels...the tires sit in a recess and are flat across. You'd somehow have to find a much thicker tire to pull that off.
----

Fritz, are you running the cool blocks for guides with these narrow blades? Euro guides are "close" for 1/4" and really not usable for things smaller. You might also discuss your issue with Sam Blasco at MM. He's a good resource for creative solutions for things like this.

[Wilbur Pan]

These Euro saws are not designed to run with crowned wheels...the tires sit in a recess and are flat across. You'd somehow have to find a much thicker tire to pull that off.


Really? I did not know about the recess. How much tire sticks above the wheel? You need less than 1/16" of a crown for crowning to work.

[Ken Fitzgerald]

Wilbur...Mini-Max says their wheels are flat. Here's a small clip from the MM-16 owner's manual:


ADJUSTMENTS TO THE PLANE OF THE WHEELS
Coplanar in Bandsaw terms means that the upper and lower wheel
faces are in exactly the same plane . This state keeps the blade well supported
for accurate sawing and blade tracking. There are differences of opinion as to
whether a flat wheeled saw such as the MiniMax MM16 and MM20 really needs
to be coplanar. Nevertheless, the following routine will indicate whether your
wheels are in the same plane and will present instructions for achieving this
advanced state.



I'm of the opinion that if the surface of both wheels are flat, it is less critical for them to be co-planar.

If the wheels are crowned, it is imperative for them to run co-planar. Again JMHO.

[FRITZ STOOP]

MiniMax bandsaws come with Euro-style roller bearing blade guides with universal head, not the ball bearing types I find on American machines.

I don't even use the lower guides and leave the uppers a bit loose on small blades. The rear I bring up close.

Maybe cool guides are the way to go as I run all larger sizes up to 1" with no problems.

I use the Suffolk tensioning method.

[Charles Shenk]

Assuming you have devent overall setup, Cool Blocks should help with the blades smaller than a 1/2 inch. I too have the newer MM16. If I had a bigger shop I would have a 14" bandsaw setup with a 1/4" blade and the MM16 with a 3/4" resaw blade.

[Jim Becker]

MiniMax bandsaws come with Euro-style roller bearing blade guides with universal head, not the ball bearing types I find on American machines.

Yup...I've owned one since 2003.... ;) I do have the cool blocks kit for my MM16, but have never put it on since I've never used a blade narrower than 3/8" to-date.

[Ron Dunn]

What is the "shudder test" mentioned earlier in this thread? I've searched the forum and can't find anything relevant, nor does a broader internet search for "shudder test bandsaw tension" return anything good.

I have an Inca bandsaw - different saw, but still flat tyres - and run 1/8th blades with no difficulty. My suspicion is that the cause is one of two reasons:

* Incorrect alignment of the top wheel (I'm talking the in/out adjustment, not this "coplanar" stuff)

* Incorrect tension (I suspect too loose)

Since you've described spinning the wheels by hand, with the blade staying in place, I'm left with suspicion around blade tension.

[John Thompson]

You can get away with not running guides on the bottom, but IMO it's nice to have their close support on top. The large bearings on the MM (most larger saws including those with large roller guides) make it difficult to clear the front of the guide with the teeth and gullet. Hence.. the reason MM offers the cool blocks which are smaller and more suited to the narrower blade.

But.. this is just from discussions with the MM reps at IWF and other WW Shows. Some of you have stated that you do run the smaller than 1/2" without cool blocks. Have you encountered no problems at all.. or worked around the one's you did en-counter?

BTW.. for those with the newer MM saws.. the lower bearing were actually located about 12" below the table on the older ones. MM moved them up closer several years ago to give better support under-neath. A great saw IMO.. but like any other machine... they have had some minor design glitches that could probably have been better.

Sarge..

[Ken Fitzgerald]

Ron,

Do a search using "flutter test". I'll try one here as I know it's been discussed.

[Ron Dunn]

Thanks Ken ... you're right ... lots of threads on this subject.

Having read some, I think we've found the cause of the OP's problems - the tension is way too loose.

[Pete Bradley]

If the wheels are crowned, it is imperative for them to run co-planar. Again JMHO.

It really isn't. I've seen internet posts that obsess over this, but as long as you're close it's really not a big deal. The definition of "close" isn't hard and fast but some machines will take quite a bit of variation. As you point out, with crowned tires the band is constantly seeking the center of the tire. That's not to say people shouldn't adjust for coplanar, just that they should keep it in perspective.

This is a good article on bandsaw tuning:

http://www.owwm.com/files/PDF/FAQ/110124076.pdf

Pete

Pete

[Wilbur Pan]

Wilbur...Mini-Max says their wheels are flat. Here's a small clip from the MM-16 owner's manual:


ADJUSTMENTS TO THE PLANE OF THE WHEELS
Coplanar in Bandsaw terms means that the upper and lower wheel
faces are in exactly the same plane . This state keeps the blade well supported
for accurate sawing and blade tracking. There are differences of opinion as to
whether a flat wheeled saw such as the MiniMax MM16 and MM20 really needs
to be coplanar. Nevertheless, the following routine will indicate whether your
wheels are in the same plane and will present instructions for achieving this
advanced state.



I'm of the opinion that if the surface of both wheels are flat, it is less critical for them to be co-planar.

If the wheels are crowned, it is imperative for them to run co-planar. Again JMHO.

Oh, I agree with everything that you're saying. My bandsaw is a Walker-Turner 16", with flat wheels and for a long time I had flat tires on it. All I'm saying is that if you are having troubles with a narrow blade on a bandsaw, crowning the tire is a very effective way of fixing that problem.

I found that with flat tires, the narrower the blade, the touchier it was when it came to adjusting it. Wide blades ran just fine. I put a crown on the upper tire, and the narrower blades became much better behaved, while the wider blades didn't seem to care one way or another.

You don't need much of a crown for this to work. I have urethane tires which are pretty thin, as you know, and don't leave much room for crowning, but all it took was to remove a hair less than 1/16" from the edges to establish a crown and to get the narrow blades to behave better.

[Steve Clardy]

I have a 1/4" blade on my MM16 now with no problems. :confused:

I have the blade adjusted back from the front of the wheels about a 1/3rd of the wheel width.