Replies

1. 
   IanC | Jun 10, 2003 05:07am | #1

   KJ,  Sometimes the motor pulley on my Delta would work itself out on the shaft so it was no longer aligned with the larger wheel pulley and caused a lot of vibration. Check the alignment of the two pulleys with a straight edge.  I'm not familiar with Jet saws so this may not be an issue. 

   Ian

1. 
   SCFrankland | Jun 10, 2003 05:17am | #2

   I found with several of my blades that I had custom made that the weld was a little off and used to knock the guides while it was running.  It maybe worth looking at the blade to see if there is a bad weld or a kink.  Also check the tires for and build up or slight bumps.  You can also look at the belt along with its alignment.Scott C. Frankland

   "This all could have been prevented if there parents had just used birth control"

2. 
   davearnone | Jun 10, 2003 06:31am | #3

   KJ, does it vibrate without the blade?

   dave

1. 
   KJ | Jun 10, 2003 03:00pm | #4

   It does not vibrate without the blade. But it does with my other blade. 2 bad blades?

1. 
   Marcello | Jun 10, 2003 09:15pm | #5

   KJ,

   So, it only vibrates when running with the belt.  Try using rubber shoes like you suggested, also getting the power twist belts between the pulleys - that alone may get rid of most of the vibration.    Make sure everything else is in alignment including the top and bottom wheels.  Urethane tires may also help in reducing the vibration.

   Have you used the saw before without experiencing vibrations or is this a brand new saw?  Sometimes when there is a slight kink in the blade, you will get quite a bit of wabble in the cut, or washboarding, or the blade tensioning may not quite be there.  There will always be some amount of vibration in these saws, the object is to minimize it and work with something you are confortable.

   Marcello

2. 
   davearnone | Jun 10, 2003 10:27pm | #6

   Some things to think about:

   1) You say there is no shaft runout.  Is there wheel runout?  Hold a pointer near the wheel radially and check to see that the tires and wheels are actually moving in a circle.  Hold a pointer neart the wheel face out near the rim and see if there is axial runout.

   2) Does it vibrate with the blade but with the blade guides completely loose?

   3) Can you get a sense of the vibrational frequency?  Once per blade rev, once per motor rev, once per wheel rev?

   4) Does vibration get better or worse as a function of blade tension?

3. 
   KJ | Jun 25, 2003 01:59am | #7

   Problem solved by placing the entire saw on a dense closed cell foam pad. Thanks for the help.

   KJ

4. 
   DennisS | Jun 25, 2003 08:12am | #8

   KJ -

   Eliminate everything down to the basic parameters and start working your way back up to see where the vibration is coming from.

   Remove the blad from the saw. Take the belt off the motor and drive wheel. Turn the saw on. No vibration? Put the belt back on but leave the blade off. Turn the saw on. Vibration?

   So on and so forth. As soon as you get to the point of 're-assembling' the saw and the vibration is present, then you've found the source.

   Now, .... I've never tried this, it's just intuition on my part as the way to trace the source of the vibration. It may not be advisable to run the saw with only the bottom wheel connected to the motor and no blade, but I can't imagine why it would hurt anything if run for a short test drive.

   All this is assuming, of course, that the tires have been cleaned, guides are clean and properly adjusted.

   Just a thought.

   Let us know if/when you find out what's causing the problem.

   ...........

   Dennis in Bellevue WA

   [email protected]

1. 
   HowardAcheson | Jun 26, 2003 07:21pm | #12

   Dennis, you have the right approuch. Trouble shooting must be a step by step analysis. There is no problem with running the motor without a blade attached. Induction motors run at a constant speed regarless of load.

   It is not unusual to have a slight unbalance in the wheels. For the upper wheel, remove the blade and slowly rotate the wheel, let it go and see where it stops. Do it a number of times. It it stops at the same spot all the time, it is out of balance and you will need to balance it.

   The tires could also have a hump.

   The blades can also have a thick weld which thumps as it runs over the tires or through the blade guides.

   Finally, all bandsaws have some vibration--at least the ones I have used. It does not affect the operation unless the saw is "walking" across the shop floor.

5. 
   eokie | Jun 25, 2003 03:26pm | #9

   Rubber feet tend to increase virbrations (allow an already out of balance object to vibrate even more). I'd first check that - all four - wood pads are actually touching, and in - equal - contact with the floor.

   Assuming your system (wheels) are truly balanced, possible culprits: 1. dust accumulation on a wheel(s). 2. the belt from the motor (even a new one quickly takes a "set") - I changed my table saw's belt to a "red-link" belt... amazing difference in reduced vibration, about 80% elimination! (minimal sound difference, though, despite the ad-hype). 3. Even "Norm's" bandsaw on TV seems to vibrate a little bit; if Norm and his supply sources can't solve it, who are we to think ours can be perfect?

6. 
   ron61 | Jun 26, 2003 12:30am | #10

   is there something on the tires? maybe like wax- I seen people cut paraffin with the band saw it lumps on the tires. 

1. 
   forestgirl | Jun 26, 2003 08:40am | #11

   Har, har, har -- this is getting funny.  Yesterday afternoon, KJ posted:

    "Problem solved by placing the entire saw on a dense closed cell foam pad. Thanks for the help."

   Little did he know, we're were done helping!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)