No announcement yet.

Need help troubleshooting Rigid 12 inch miter saw motor noise

  • Filter
  • Time
  • Show
Clear All
new posts

  • Need help troubleshooting Rigid 12 inch miter saw motor noise

    It might be a model ms12500 (The back is marked Tool 40J7, E85575A). I was using the miter saw to cut holly wood branches into small disks. On my next to last cut, a piece of the wood launched into the blade guard and another piece went over my head. I'm fine. A friend and I disassembled the miter saw to clear the jam. After reassembly, the motor is making a grinding noise. This with and without the blade installed. Please see the video link to hear the noise. It's like something is grinding or dragging on the motor?

  • #2
    It certainly sounds like somethings going on . If the blade has no wobble to it ( possible bad bearing ) I would disassemble the arbor housing and check the gear that drives the spinal to see if jamming of the saw caused any damage to the teeth .


    • #3
      I think I'm hearing a ringing noise when you release the start, is that just background or is it the blade, that's making that noise? I see you have the guard off and presume that you've cleared any debris, chips etc. With the saw unplugged, what does it feel like when you rotate the blade by hand? At the camera angle, I can't see any wobble or tooth damage, although it rotates so fast it's difficult to really see an irregular tooth; but rotating it by hand, can you notice any? Further, there isn't anything stuck or damaged in the upper guard is there. Like I said, I'm hearing a ringing sound, similar to what I'd hear if you struck the blade when it was still, except that in this case I'm hearing it trailing the sound of the rotation. So, check the inside of the upper guard, if you haven't done so already.

      It also appears that you have some vibration there, as I noticed the table lock knob rotates as the saw is running. I have no such movement when running my 10-inch, nor does my saw stop all that fast on trigger release, IIRC. (Perhaps that's just the difference in models though, I'll go out to the shop in the morning and see.)

      Beyond that, I agree with Mr. Scott, you'll have to open the motor housing to explore further. I've never had my miter saw disassembled that far, so I'm not sure about any gear. My presumption, without referring to the parts list, was that it was direct drive... I just looked at the parts list for my CMS (MS1065) and it gives no close detail, I just see what may be some kind of teeth on the end of the Arbor Shaft Assembly and in the motor illustration, what looks like a spiral on the end of the armature (both really poorly illustrated and the motor illustration was illustrated in reverse of the other assemblies, which is really very poor practice for any illustrator.)

      Sorry this isn't more definitive, but check out our suggestions.

      Last edited by CWSmith; 11-10-2020, 08:11 PM.


      • #4
        The spindle /arbor gear should look like this one.

        Click image for larger version

Name:	spindal gear.jpg
Views:	53
Size:	17.7 KB
ID:	747078

        One way to test without disassembly is cutting a piece of wood .... going into the wood if the sound becomes high pitch or if your blade slips /slows down than the gear is probably worn ... It disassembles easy with only a few Philips head screws holding it in .


        • #5
          Thanks for posting the picture, that's gives me more clarity on what they were attempting to illustrate in the exploded-view parts illustration. So, the spiral gear machined into the end of the motor shaft mates with the side of the "spindle/arbor gear".

          With that understanding, it may well be that the shock of hitting the blade knocked the arbor slightly out of position and instead of being proper engaged, the motor shaft isn't meshing properly. Hopefully neither gear is damaged too badly. That may also explain why the saw is stopping so quickly when turned off. I tried my 10-inch CMS this morning at the blade comes to a halt a bit slower than in the video shown. I realize that both saws have a braking mechanism, but my MS1065 is almost in new condition as I don't use it all that much.