Best way to fix a bandsaw wheel wobble & vibration?

[Jonathan Jung]

Working on getting my old Tannewitz 24" bandsaw going. Even with the blade removed, there's a vibration when running and the bottom wheel wobbles back and forth a bit. About 1/8" side to side.

I've checked the arbor runout. Seems to be within .001" at the end.

With the lower wheel removed, there's very little vibration, but the bearings have one coarse-sounding spot. I put in two pumps of high quality bearing grease. Not sure if I have to put in more (see other thread).

I don't want to replace the tires (see other thread), but I also want to fix everything properly.

Tomorrow I'm having a machinist stop in to take a look, possibly to true and balance the wheel. Surely Northfield wouldn't let a machine go out with wobble and vibration? Looks like there's a balancing plate added on the backside.

What amount of side-side wobble is ok, and how good should the balancing be?

[Tom Trees]

Not familiar with Northfield's machines either, so unsure if things are the same deal as with, say flange mounted motor flavours like the Centauro CO for instance.
Either way, this method could be used.

I found that the upper wheel on my 24" machine had 0.5mm discrepancy, when using a scribing beam registered off the wheels.
My lower wheel had about half that.
The scribed line from the upper wheel (the datum on most bandsaws, as it's non adjustable)
was having 4mm variance on the chassis base.
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I didn't rig up a false floor to the centre of the lower wheel to find out how much that might be reduced,
and I didn't do the opposite with the lower wheel either,
but one could imagine both sections of the wheels at maximum distance apart could amount to a tad more than what I've shown.

Here's a recent thread featuring the scribing beam, if that's an apt name for it, or whatever.

https://sawmillcreek.org/showthread.php?305298-Centuro-compact-bandsaw-(600)-guide-questions/page2&p=3274796

I also posted a glut of posts elsewhere north from you folks yesterday, regarding a lousy method of dressing your tires, thereafter the job what's in the thread above.
Should you be trusting the edge of a wheel, what might have a discrepancy whilst dressing or gluing down new tires.

All the best
Tom

[Erik Loza]

Jonathan, I would replace every bearing in a machine of that age. It’s conceivable that the lower wheel threw a weight but that would be rare. Are you familiar with the sharpie trick? With the wheel mounted, but no blade installed, make a mark at some point along the outer perimeter of the wheel with the sharpie. Spin the wheel a few times and note if the sharpie mark lands in the same spot once the wheel stops spinning. This is a pretty simple way to eyeball whether it’s a wheel balance problem or if you need to dig deeper.

Erik

[Richard Coers]

The only way to fix wobble that isn't a bearing issue, is to have the wheel machined and balanced.

[Jim Becker]

I'm with Erik...on a restoration like this, IMHO, it's a best practice to replace bearings as a matter of process which also allows for better overall cleanup due to the disassembly required to replace the bearings. If the wobble and wheel tracking continues to be off after replacing the bearings, then either the shaft is buggered or there is a balance issue with the wheel itself.

[Bill Dufour]

I do not think an automotive dynamic balancer can do a wheel with too small of a hole. But it sounds like an interesting idea for a high school or Jr. College shop. Big wheel like that one may need a big rig wheel size machine.
The old spirt level balancer should be able to handle any size wheel for static balance. You could make one with the taper part supported form a string coming down from the ceiling.
BilL D

https://www.amazon.com/MOTOOS-Portable-Balancer-Bubble-Diameter/dp/B07XDWSLDG/ref=sr_1_33?keywords=tire+bubble+balancer&qid=1697240645&sr=8-33&ufe=app_do%3Aamzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc

https://automotiveequipmentspecialists.com/ranger-dst-2420-dynamic-wheel-balancer/?_vsrefdom=adwords&gclid=EAIaIQobChMIz8vTuJr0gQMVKwStBh21FQjWEAQYAyAB EgLuhPD_BwE

[Bill Dufour]

Sounds like 1/8" is too much wobble. For lesser amounts you can grind the tires to be true. But tire grinding does not really affect balance much. Be careful and mark relationship of wheels to shafts before removing. They may have been balanced as a unit.
Bill D

[Richard Coers]

Is there any evidence that the machine fell over or was dropped? Hard to imagine it went through its entire life with that kind of wheel wobble. Now I would have believed it from a new Chinese bandsaw, I was shipped one of those. One side of the bottom wheel was filled with big drilled holes, and they bolted steep plates on the other side in an attempt to balance it.The didn't get there.

[Tom Trees]

One can see Jonathan has another post on OWWM, where he mentions the tire being loose in one spot.
I'd find it interesting to see if that would correlate with the maximum discrepancy of the wheel, be it on one face or the other,
as it might likely explain why.
Simple tramming tool (an old saw clamped to a block works quite well, protect yer paint with tape)
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I'd post there, but seems most of the response I got before was "overcooked", so seemingly by that reckoning, the blade will happily bend to confirm to what could be a massive gap between the wheels.
I think there maybe an overly appreciative or sympathetic view of machine design on that place, as I see some oddly designed saws crop up from time to time,
wooden parts or whatnot.
Seeing as the scribing beam don't lie, it was likely distasteful on such a forum, what I would'a thought, appreciated for those who have vulcanized tires needing remedying,
for those on a shoestring budget.

I'm not a maths or physics guy, infact quite the opposite, but I'll pretend for a minute.:rolleyes:
As seen earlier, I mentioned that my upper wheel had 0.5mm discrepancy, which turned out to scribe a 4mm variable line on the chassis base.
One could speculate the measurement could be taken from the end of the timber, rather than a measurement from the middle,
so perhaps one wouldn't need rig up a false floor on the centre of the lower wheel, since the end of the timber (on my machine)
is about the same distance away from it, as the pen is, away from the lower wheel.

Regardless of which that may be...I'm still only accounting for the error of a single wheel,
and might I add, I couldn't see that 0.5mm variable by hand turning the wheel.
That should highlight some food for thought.
All the best
Tom
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[Jonathan Jung]

Thanks all. Once I sort out the tire issue, I'll cleanout and possibly replace the bearings then check the balance with a sharpie and using magnets as weights.

[Tom Trees]

Four chances of balancing, for those who might be partial to a drill.
Front face, rear face, and easing the edges on both aswell, as one may see some inconsistency after dressing, possibly unsightly for some!
They must have use some kind of spring loaded grinder for my Italian wheels.

That might be worth a thought if the error was small, not needed to mess about with balancing myself thankfully.

[Ole Anderson]

Start with the bearings. My 15" Craftsman BS was really noisy. Opened it up and saw the little serpentine belt was nearly in pieces, well that explained it! Had to remove the lower wheel to get to the belt, and noticed one shaft bearing was nearly seized. New Timken bearings from Amazon and a new belt and all is now good.