[OP]
Contributor
My 32" Centauro ST 800 band saw vibrates like crazy, and I'm thinking of bolting it to the concrete floor.
The wheels are balanced, they have max 10/1000" run-out on the edge of the rim, just a few thousandths on the rim, they are coplanar. The brand new blade is welded straight.
The saw has a sheet metal body, and so is not that heavy, maybe about 1,000 lbs.
Any thoughts?
Should I use a dampener of some type, maybe like this one?
Screenshot 2024-03-17 at 11.07.12 AM.jpg
thanks, Mark
Contributor
Your bandsaw vibrates like crazy. That’s not right. I’d track that down, and fix it.
Member
You could try aligning your bottom wheel and motor to suit the upper wheel.
Either by a scribing beam on wheels accurate enough to draw a straight line,
or laser pen on an extended shaft affixed in place of the wheel retaining bolt & washer,
Datum scribed.jpeg
And if your Centauro has a foot mounted motor, and not a flange mounted one, then it's likely readily adjustable without
determined intervention.
i.e adjustable mounting plate for flange mounted motor.
Motor alignment 1 .jpg
That plate being adjustable on two axis, provided column is checked prior to adjusting co-planar..
(not wanting to do this, if likewise, then you'd better have loose belts, cuz things can get nasty in an instant)
Some tips for levelling and checking that portion of the column might be of interest
Old blade being suggested for such checking, due to the set of the blade being compressed.
Four blocks for settling both levelling plumblines, backlight, could use tape instead of magnets
a third line for wheel depth, or accounting for differing tire thickness, the latter not likely important on Centauro saws.
SAM_4964.jpgSAM_4960.jpgSAM_4977.jpgSAM_4997.jpg
I was chasing my tail attempting wheel alignment with a beam and rule, until I used the tape on the base,
as the beam (now with scribing function)
showed that a 24" wheel needed to have the faces or the rim, dressed to within 0.2/0.3 or thereabouts, and not 0.5mm as my upper wheel was,
in order to draw a straight line...
as depending on where the beam is placed beforehand, would potentially give a misreading of around 4mm.
So if trying with a scribing beam, rather than laser, then check every spot on the wheel, in order to see the pen landing on the line,
i.e not getting another line parallel to it.
Without trued wheel faces .jpg
I'm sure you can find the rest of the spiel.
All the best
Tom
Last edited by Tom Trees; 03-17-2024 at 3:36 PM.
Contributor
Take the blade off and turn it on. If the vibration is the same as with the blade on, then the problem is somewhere in the lower wheel/bearings/drive motor. If it doesn't vibrate then the problem is in the upper wheel/bearings or blade.
John
Contributor
I would like to suggest you look for a twist on the base. I had a laguna saw that had a nasty vibration sitting in one spot but ran smoothly in another.
My remedy was to shim under the base on one corner.
The base metal was very thin on the laguna saw.
Good Luck
Aj
[OP]
Contributor
John, the saw runs without any vibration without the blade being installed.
The bearings are new, the wheels are all balanced, and I think they are not out of whack on any axis - but I'll have to read Tom's method a few times to gain a better understanding.
Plus it's the same outcome, vibrating like a banshee, with three different blades.
Which has me thinking about bolting to the floor, but if there are specifics I should look at regarding the upper wheel that I'm not aware of, I'm happy to follow any line of inquiry.
Andrew I'll look into the frame being possibly twisted, thanks.
Jamie, for sure. That's my hope!
Contributor
Andrew's post leads to another thought, or maybe its the same one. Maybe your floor is not flat, so the saw is rocking - more than it is vibrating. With the power off, try rocking the saw. If it does rock, slide a thin wedge or shim under one of the high corners until it doesn't rock. The turn the saw on, and see if you've fixed it.
Contributor
Mark, if the saw has no vibration with the blade off, and it vibrates with 3 different blades installed, then that suggests the problem is in the upper wheel/bearings/spring/carriage. Were the wheels statically or dynamically balanced? Static balancing doesn't necessarily mean all is well, but if you are confident the wheels are ok, then I'd be looking at those other things.
If the saw runs smoothly with the blade off, then bolting it to the floor doesn't seem like it's necessary.
John
Contributor
I suspect the top bearings won't last long if you do bolt it to the floor. The vibration will still be in the machine and it has to go somewhere. That means the bearings. Take the blade off and spin the top wheel. If the vibration is really that bad, the heavy spot in the wheel will always end up on the bottom. Mark that spot and spin a few more times. If that spot always ends up at the bottom, zip tie a few washers to the top. Drill two small holes through the wheel and zip tie if you can for a permanent solution. You could epoxy the weights on there as well.Originally Posted by Mark Gibney
[OP]
Contributor
I don't know what the terms static and dynamic balancing mean, and I spent about ten minutes trying to get an understanding from googling the terms, but am none the wiser. Most search results come back about car wheels and the computerized dynamic balancing available.
I spun each wheel over twenty times, marking where it settles, and adjusting with small added weight if necessary. The repeated the 20+ spins.
The upper wheel didn't have any repeated pattern of where it stopped. The lower wheel did, and I added about 1/2 oz weight. After this it was random for 25 more spins.
My local band saw place said they can balance the wheels, but they use the exact same method, just some dude spinning the wheel by hand and so on.
Member
My 20c worth. If you bolt it down something is going to break so that would not be a good idea. I presume you have spun the bottom wheel using the motor with no blade and it does not vibrate, now get a socket and adaptor for a drill and spin the top one and see what happens, if that is ok add the blade and remove the motor and drive the assembly with a drill. The vibration is caused by something rotating so it needs to be tracked down systematically. Balancing as you have tried is static balancing, dynamic balancing is done with the part rotating at a fairly high speed which could be attempted using a drill but it would be very hit and miss and not something I would do.
Chris
Everything I like is either illegal, immoral or fattening
Contributor
My little mill/drill had a sheet metal guard vibrate like crazy. I was going to paint it inside with grafting seal to soak up the vibration. I stuck a free harbor fright magnetic parts tray on the side and it no longer makes any noise. that extra weight was enough to calm things down.
BilLD
Contributor
What is the condition of the tires on the saw?
I saw big vibration improvements on a 14” Delta clone I had after replacing the old rubber tires with urethane tires.
When a glue bottle is open, your IQ drops 50 points. - Chris Schwarz, The Anarchist’s Workbench
Contributor
bill dux seal works best, it comes in pugs past 5 lbs now cant find the same supplier I did my general bandsaw covers big difference but need to do the base. Been tryhing to find a supplier for quantity and the distrbutor gave me their places and they are whacked price wise id pay less a home depot stupid. Past bought it wholesale in quantity so still trying to find a supplier of it and will.
Contributor
Grafting seal is very similar to water based roofing tar. Truck bed lining is possible as well.
Bill D
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