Replies

1. 
   saschafer | Apr 11, 2008 04:54am | #1

   That sounds like a bearing problem. Perhaps one of the wheel bearings has run dry?

   Regarding the flutter, did you back the guide blocks and thrust bearings off completely?

   -Steve

    

1. 
   gaffer | Apr 11, 2008 05:04am | #2

   I was thinking wheel bearings, too, but hoping something easier was in play. Can you mess up bearings by tensioning to tight?
   Flutter: No, I don't think I backed off the roller bearings or the thrust bearing. Sounds like you're telling me I should have. I guess that would allow more flutter.

1. 
   saschafer | Apr 11, 2008 05:29am | #5

   In principle, you could overload the bearings with excessive blade tension, but I think you'd have to overtension the blade for a very long time before that would happen. More likely, one of the bearings had a bad seal and just ran dry.

   Another possibility is that the drive belt is loose. This would cause the same kind of squeal as you get in a car with a loose belt when you turn the wheel against one of the locks and the power steering pump complains.

   You do need to have the blade as unconstrained as possible in order to see the flutter. That said, I'm not a big fan of the flutter method; it doesn't seem to be very repeatable.

   -Steve

    

2. 
   andyfew322 | Apr 11, 2008 05:15am | #3

   what's the "flutter" approach

    

   There's enough youth in this world, how 'bout a fountain of SMART??!!

1. 
   gaffer | Apr 11, 2008 05:20am | #4

   The procedure often suggested that involves backing off the tension until you see the blade "flutter" and then tighten a half turn or so. Supposedly gets you to the right place.

1. 
   forestgirl | Apr 11, 2008 10:31pm | #11

   Gaffer, your description is incomplete and incorrect.  Instructions are here at Suffolk Machinery.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

2. 
   forestgirl | Apr 11, 2008 10:29pm | #10

   Gaffer gaffed on his response to your question about "what is the flutter method."  Before responding, must make the point that this method is recommended for the low-tension silicon blades made by Suffolk Machinery (the Timberwolf blades).  You can read the description here, but to summarize, you loosen the tension until you see a flutter and then you retension a small amount at a time until the flutter disappears.  Then you add a bit of tension.

   It is important to read the complete instructions on their web page.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-) 

3. 
   davidbrum | Apr 11, 2008 07:55am | #6

   Any chance that the upper wheel is hitting the wheel cover at he top? I can imagine an aluminum wheel making that kind of noise if it were rubbing on something.

   david b

4. 
   BruceS | Apr 11, 2008 04:38pm | #7

   Try checking the weld, since the sound started after changing the blade.   Mark the blade with white chalk at the weld and run the saw and see if the noise happens when the mark is near the guides, or back off the guides and thrust bearings and see if the noise stops, process of elimination.  I've also had poorly welded blades that didn't lay flat and"surged" forward and back and the teeth caught the guides on the backward surge.

   Work Safe,  Count to 10 when your done for the day !!

   Bruce S. 

    

5. 
   JohnWW | Apr 11, 2008 06:35pm | #8

   Bearing problems wouldn't cause an intermittent sound like you are describing, but a raised or kinked spot on the blade would.

   Tension the blade moderately, center it on the wheels, back off the guides so they are definitely not touching the blade and then rotate the saw by hand and see if you still hear the sound. You will probably find the blade, often time at the weld or a kink, is brushing against the blade guard at the back of the saw or a door clip. You can usually adjust the offending part to eliminate the interference.

   Another good possibility is that the upper wheel, which is raised higher than normal to tension the longer blade, is now rubbing against the back sheet metal cover either at the rim or possibly at the hub where the wheel is attached to the tension and tracking assembly, this can be hard to see.

   If there is no sound, move the upper guides, one at a time, thrust bearing first, against the blade and see if some wobble or kink in the blade is making the blade touch the guides only intermittently as you turn the saw by hand. Fairly often a blade will have a misalignment at the weld.

   The flutter method is inaccurate and pointless. Moderate tension, judged by finger pressure against the side of the blade will get the tension set correctly.

   Sawing problems are almost always due to using the wrong blade, typically too fine a tooth spacing, or at least 95% of the time, the blade being dull, even though it will still feel fairly sharp.

   John White
   (Author of "Care and Repair of Shop Machines")

   
   

   ---

   Edited 4/11/2008 11:41 am ET by JohnWW

6. 
   SawdustSteve | Apr 11, 2008 06:35pm | #9

   Hi Gaffer..... If you have the ball bearing guides and not the standard 'steel' guides, it sounds like the blade is slipping past the rear 'thrust' bearing (usually the upper one). I had that problem and it turns out that I was rounding off the back of the blade too much. Now I just touch the back of the blade lightly with a stone and no more 'barking' sound.
   SawdustSteve