I have a powermatic table saw, 7 years old with a 2 hp baldor motor and when i start it the motor hums but the blade just shakes back and forth. I can turn the blade by hand and rotate the motor fan blades, Ideas?

Simple solution: switch two of the wires. Doing so will reverse the direction of the motor. You can switch it at the motor or on the electrical plug end.

Check to make sure the arbor set screw is not loose. The bearings may have shifted when you moved it. I recently rebuilt an old 66. Repositioning the bearings and tightening the set screw could be all it needs.

Before you go into motor defects, is the drive belt tight enough?
Alex

On the Powermatic 66's the first two numbers are the year in which it was made, so yours was made in 1997. The second set of two numbers is the model. The last numbers I"m unsure of but its my understanding that they represent the manufactured number, so yours was the 1,400th saw made for that year.

http://www.baldor.com/support/literature_load.asp?ManNumber=MN1240
You didn't give a model,here's a manual on their motors and the wiring diagrams,they start on page 2-9.It should get you there,or you can check out their other manuals on the same page .Take care!

http://us.husqvarnacp.com/

drop down menu "service"
click "service literature"
click "old target, dimas, partner literature"
enter model number
pdf has basic wiring diagram page 4 or so

Either it has a problem with a blade brake or the motor is siezing. Or the is a wiring problem. With the unit unplugged check and see if you can turn the blade by hand, if not the motor is the problem. If it does you could still have a motor problem by it drawing to much amperage or the is a wiring problem.

Sounds like the power feeder is not holding it secure at the end of the pass. Is the outfeed table running level to the saw table?
Just a wild guess, I'm afraid. I haven't used one myself.
The only time I've seen blades wobble like that was when they were light plates, undersized for heavy duty ripping operations. It's truly frightening to watch them overheat and turn to butter like that. I'd recommend getting a heavier plated saw blade if there's any question about yours.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!

No. Unplug saw remove saw blade grasp shaft that saw blade was on wiggle back and forth. Should not be too much play. After 10 years motor bearings are proably worn. Easy to replace

Your saw motor is equipped with a two speed internal start switch. Over time saw dust will get into the contacts and cause the points to burn. You can pull the end off of the motor and take some 400 grit sandpaper to the contacts to clean them( there are two sets of contacts one works in the out position the other in the in position) it will be the set in the in position that is the problem. Gentle clean them, reassemble the motor end cap and it will work fine. I have to do this about once a year to my saws. I use my saws about 25 hours a week. I have been doing this to one of my Powermatic saws for 31 yrs. now.