Hi,
I use a 15″ General bandsaw and to tell you the truth I’m a little bit timid about using it.
How much wheel vibration should there be? The top wheel vibrates up and down on the blade tensioning spring 1/8 to 1/4″. I’m using a 1/2″ blade with the tesioning spring set for a 3/8″ blade. My cuts are very light – 1/2″ thk ceder boards. Sometimes the saw seems to run at a critical vibration frequency and the vibration gets a lot worse.
I have checked the wheel and motor bearings and there does not appear to be a problem.
Do I need to worry or is this normal?
Help would be very much appreciated,
Terry
Replies
terry,
I'm gonna take a guess that the spring has lost its Uummph. I wouldn't think ½" thick cedar boards would cause the upper wheel to rise/fall by up to ¼".
Just guessing,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 8/14/2008 2:52 pm ET by KiddervilleAcres
Bob,
Thank you for the reply.
I checked the spring and it seems to create an adequate tension on the blade, so can I rule this out?
Terry
how are you determining "adequate tension"?
Hi Woodman41,
I'm flexing the blade at the back of the saw between the upper and lower wheels. There is very little deflection.
Thanks,
terry
If this is a new saw for you, then you may want to try a couple of things that helped me sort out the vibration on my 14 inch Ridgid bandsaw.The first thing that I did was change out the drive belt. They come with an automotive style v-belt and they tend to stiffen with age and develop a "set" at each end where it sits across each pulley. I went to Woodcraft and purchased a replacement segmented belt that they sell to improve the performance of table saws. That change took away about 50% of the vibration that I was getting.The next thing was to order a replacement set of cast iron machined pulleys, to replace the stock non-machined pulleys which, it it said, are often not really round or concentric around the shaft. That change made another big difference. Then I static balanced the wheels. This made no appreciable difference.Finally, I stiffened the mounting table/leg assembly with 3/4" birch plywood. That took the last of the noticeable vibration out of the machine.Hopefully, some of this will work for you.
P.S. I found all these suggestions in a FWW article on tuning bandsaws.Best Regards,
MikeD
Hi terryl Had a similer problem with my saw.Couple years ago i messed up the tires on my 16 saw.Turned it on with out tension on the blades.I had to send the wheels out to a saw sharping service to put new tires on them.Could not do it mt self.Guling them on is no problem getting them round with a crown is hard.The tires have got to be round or the top wheel will hop.Hope this helps.
To sort out the vibration issues, it helps to isolate the components and measure the vibration at each stage. If you have a dial indicator, mount that to the table with the point touching a nearby machine or wall and then note the total movement of the dial as you check each component. The first thing is to remove the belt and run just the motor - there should be nearly no vibration. Then reattach the belt, but with no blade on, turn on the machine. If you have excessive vibration it is either due to the lower wheel or the belt - by changing the belt you can eliminate that as a potential cause. If the vibration is still bad with a new belt, you may have to rebalance the lower wheel - see http://wiki.owwm.com/BandsawBladeBalancing.ashx
Once that vibration is down to acceptable, put on a blade and run the saw. If you have excessive vibration, it is either the upper wheel or the blade. I would change out the blade to see if it is the blade or the wheel, if the vibration is the same with a new blade, then rebalance the upper wheel. You can also get some vibration if the upper wheel is out of round or wobbles, and you can test that with a dial indicator , though the fixes for those conditions are a little tougher.
Thank you Barry I will follow up on your procedure when I get back off vacation. How much tension should be on the drive belt [it is quite slack] and is a link type belt better than the solid belt I'm using now?
Regards,
terry
I switched from the standard belt to a linked belt and noticed an immediate improvement in vibration - it was less than .001 with the link belt ( without the blade) OTOH, some say that the manufacturer supplied belt is not the best and that an automotive cogged belt is better at transmitting power than a link belt. I have noticed any slipping with the link belt with a 1 inch bandsaw blade, so I can't speak to that. I would tension the link belt to the manufacturer's recommendation - usually it will be to try to pinch the belt and if it moves more than x it is too loose. The amount of movement would depend on how far the belt is unsupported ( the distance between the two pulley's) If you don't have the owners manual, I would think you could find some help online.
Hi Barry,
The link belt solved the problem. Now I have very little vibration at full speed but it still shudders a little as it comes to a stop. I wish I could also amke the saw run with less noice.
Thank you very much for your help.
Terry
Terry, you might want to try to isolate the noise - if with the belt off, the noise is very loud - then either there is a problem with the motor, or the mounting is loose and it is vibrating. As you add components, you should see the noise gradually increase - if there is a dramatic increase, the component you just added is the noise. Usually, the noisiest thing on my bandsaw is the thrust bearing - if it is making noise when I am not cutting - it means it is adjusted too close to the rear of the blade. As to the vibration while slowing down, I wouldn't worry about it since you aren't cutting then. If you want to try to eliminate it- check the alignment of the motor pulley with the lower wheel pulley ( which may be hard to do ) If they are out of alignment that can cause some vibration when slowing down. Also try changing the tension a little each way and see which is better. Barry
Thanks Barry I will do as you suggest
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