is my saw dying?

[Bill Bixby]

I'm getting this strange screeching sound on startup and a vibration as well. Can anyone tell if this is a symptom of the brushes going bad?

http://www.youtube.com/watch?v=OA2F6z_D0MU

http://www.youtube.com/watch?v=yI-uZAbhGMc

[Bob Wingard]

If that's a direct-drive saw, bad brushes could be the cause of the noise ... bad bearing(s) could cause the noise AND the vibration ... I'd suspect bearings are your problem.

[hank dekeyser]

Grab the blade and how does it feel when you rotate it by hand ? (unplug the saw first) It should feel smooth and turn easily. Unfortunately you stopped the video too soon to listen to the saw actually stop. Another problem could be the windings on the motor got HOT and are interfering ?(kinda doubtful) What did you do the last time you used the saw BEFORE the noise started ? How did the saw sound, were you ripping 3" thick oak, etc ??? It looks and sounds like a direct drive saw, usually when the bearings go its almost cheaper and easier to replace the saw (or buy a used one w/ a good motor and swap it over.

[JohnT Fitzgerald]

Is that a Delta 34-670?

+1 on bearings and brushes, but brushes should be your first stop - I had a saw like that with problems like that. It had sucked in a lot of PVC (Azek) dust/strings that clogged up the brushes and the air intake. Flip the saw upside down and it was pretty easy to get to the brushes w/out removing the motor. Compressed air and a little time is all it took.

[Bill Bixby]

It is in fact a 34-670. I believe the sound started about a month ago when I was ripping a piece of plywood that got a bit sideways and pinched the blade to a stop. It only made this sound occasionally so I've continued to use it and about halfway into each cut, the vibration stops.

I found a replacement motor for $175. http://www.ereplacementparts.com/motor-15amp-1ph-p-111210.html

I cant think of another way to get up and running for any cheaper than that.

[JohnT Fitzgerald]

It is in fact a 34-670

I thought I recognized the sound - it's a little 'screamer', but one of them served me well for years. Could be a damaged bearing - I have no experience replacing them but from what I've read it's not that tough. If you have the time and inclination, a tear down & cleaning of the motor, replacing the bearings, could be in order. If you need the saw running more quickly than that, maybe a new motor - although at that price, I've seen used -670's on CL, so maybe you can scavange the motor from one while rebuilding the other. I'd still try the brushes first though - should not take that long.

[Bill Bixby]

Thanks for the help! I will try working on the bearings and brushes.

[Jim Heffner]

Sounds sorta like dust, crud build up in that motor to me. Unplug the saw, raise the blade all the way, remove the blade and take an air hose, blow out the motor as best you can, especially on the end where the arbor is and then plug saw back in an run it without the blade and see if that makes a difference. Then try it with the blade and see if the saw sounds different than before.No one else said this ...have you changed blades recently? Different blades especially a new sharp one sound different than a dull one does...try it you may see what I'm saying here.When I clean out one of my saws I usually spray a little(lightly) WD-40 around the shaft ends of the motor makes a difference and it doesn't hurt the motor....may help quiet a noisy but still usable bearing for a long time.

[Steve H Graham]

Ebay is great for motors. You can save a ton. Just make sure you buy one with the same frame code or one which is compatible. Somewhere out there, you will find a chart listing all the frame codes so you can compare shafts and so on and make sure you don't buy a doorstop.

Whoops, I found it: http://www.motorsanddrives.com/cowern/motorterms2_tbl1&2.html

This is a fantastic reference well worth bookmarking.

[Mike Desch]

First thought would be a bearing.

Happened to me on my old BT3000. bearing seized up and motor would not even start.
Took saw apart, removed motor and bearings, took bad bearing to a motor rebuild shop and got a new one.
LOTS of labor, but only a few bucks for the bearing. Saw has been working great ever since.
Save your $$$ until you are convinced that the motor is bad.

[Bill Duffy]

Hey Bill - my Delta 34-670 has been making this same noise for a while. But it really got worse in the last couple of months after some heavy use ripping green 3" stock. Just curious if you were able to fix your's by blowing out the brushes or changing a bearing. I was assuming the drive belt had lost its teeth and that was the cause of the screech on start up.