Replies

1. 
   lat_axe | Feb 16, 2021 03:58am | #1

   Whilst I'm not familiar with the innards of a sawstop I can mention a couple of causes of a vibrating blade giving symptoms such as those you describe.

   1) Sticky sawdust on the drive belt or in between the blade and the arbour.

   2) Damage to, or detritus in, the bearing of the motor.

   3) Movement of the motor assembly on its mounting to the saw's case or bed.

   4) Damage to the blade from an untoward event (maybe even being grabbed by that sawstop stopper, in your case).

   Can you get at the arbor and motor to clean out any detritus?

   Does the blade have any movement on the arbor when it's stopped and you push & pull at it?

   You would recall any "untoward event"......

   Lataxe

1. 
   b_wil | Feb 16, 2021 10:42am | #3

   I’ve done my best to clean out any excessive sawdust around the belts and it doesn’t appear that there is any buildup in the grooves. I haven’t had any “traumatic” events with the saw or blade itself - no brake cartridge activations.

   I pulled the blade again this morning and cleaned the arbor - although there wasn’t any dust/dirt buildup in or around it.

   The blade doesn’t move at all unless I use a substantial amount of pressure when mounted on the arbor.

2. 
   EdWeber | Oct 21, 2021 10:17am | #13

   I would say #3.
   Blade not aligned with miter slot

2. 
   geedubbee | Feb 16, 2021 09:27am | #2

   That belt condition does look odd for a new saw. It is surprising how little it takes to add irregularity to the cutting result. Once you have nice clean cuts, anything else just seems wrong.

   The fact that you get the same misbehavior with different blades pretty well removes the damaged blade possibility. You say you cleaned the blade but, inspect the arbor face to be sure something hasn't fastened itself on there. There is a technique for widening a cut that involves slipping a piece of paper between the arbor face and the blade to purposely create a bit of wobble. This is what you're looking for.

   The other usual suspects have been mentioned; unexpected movement of the arbor by push/pulling on the blade when installed, spoil on the belts or sleeves. Dust collection is another thought; are you pulling the spoil away?

   Please let us know if the belts do the trick.

1. 
   b_wil | Feb 16, 2021 10:49am | #4

   Yeah, it seemed a little off to me as well, especially with it being so new. But it’s also strange that I ran the saw a few hours in total last week, didnt touch it and then yesterday everything was off.

   I re-checked the arbor this morning, couldn’t see anything, but re-cleaned it just to be sure. I always run my dust collector when working and keep things fairly clean inside the cabinet as well. I tend to get in and make sure there’s no excessive build up every few weeks (I’m a home shop - so it doesn’t get daily non stop use)

   I’m not sure I understand the widening cut technique you mention, do you mind elaborating on that?

   Once I replace the belts, I’ll post an update (hopefully it’s the fix!)

   I’m just frustrated since everything else seems to be in alignment, I’m trying to understand how I’m getting such rough results.

3. 
   b_wil | Apr 12, 2021 04:56pm | #5

   I know it’s been a while, but I said I’d update when I got everything fixed up and wanted to wrap this post up for anyone that might stumble upon it experiencing the same issue.

   The belts took a little bit longer to receive due to supply issues, but long story short, received them, swapped them out fairly easily (I must say, sawstops service videos are a great help,) and I’m getting clean cuts again!

1. 
   john_c2 | Apr 12, 2021 06:05pm | #6

   Good to know. Did you see anything wrong with the belts you took off?

1. 
   b_wil | Apr 13, 2021 02:28pm | #9

   The arbor belt was fine when I pulled it off and I even considered just keeping it on there, but ultimately replaced both. The motor belt had some weird rubber build up in a few areas as I tried to show in the picture in my first post. I was able to remove the build up with a small pick, but it left some marks.

4. 
   mikaol | Apr 12, 2021 07:32pm | #7

   Or pitch buildup on the blade.

1. 
   b_wil | Apr 13, 2021 02:29pm | #10

   Both blades I used were less than a month old with little use and I cleaned them to double check.

5. 
   fourier_transform | Apr 13, 2021 12:52am | #8

   You mentioned that SawStop was sending a new motor. Did you that happen? Or did you just replace the belt?

   If the problem recurs, my hunch is that there is a bad bearing in the motor. Or maybe the spindle in the motor is bent. At 3600 rpm, very small problems in either the bearings or shaft can cause the problems you are experiencing.

   If the problems recurs, I'd also measure the the run-out of the shaft. The absolute most you should see is .001" and I would normally expect to see less than .0005".

1. 
   b_wil | Apr 13, 2021 02:34pm | #11

   They only sent me replacement belts. I apologize if my original post made that somewhat unclear.

   In my few weeks of waiting for the belts, I went through with my dial indicator to check everything I could think of. Both the arbor and the shaft barely registered any movement of the needle, all staying well within .001”

6. 
   user-6204901 | Oct 21, 2021 06:39am | #12

   Probably too late down the line, but I recall reading some years ago that the Forrest folk, prior to demonstrations, install a "blade stabiliser" - quarter inch steel disk with at least 8 grub screws around the edge to set the blade perfectly- it does reduce a little the cutting depth, but I have had HUGE success doing this on a number of cheap saws with cheaper blades, to the point where the cuts generally don't need any finishing, they are so smooth. Of course the set-up does take time, so quick blade changes suffer, but the quality of the cut with a "stabiliser" is dramatically better, in my opinion