Delta Contractor saw Issues

[npregion2]

Once again I am coming to this forum for advice. I started to notice vibration from my Delta contractor saw. I pulled the belt from the motor and pulley. When I spin the pulley by hand it seems to be out of round. I am assuming it is the bearings for the arbor. Is it a big job to replace the bearings?
Thanks in advance Nick

[eezlock]

Delta contractor saw issues

Are you saying the pulley you spun by hand was the one on the motor?
If so, while the belt is removed, grab the pulley and see if there is an amount of lateral movement in the shaft when you pull/push the shaft in and out like you are trying to pull the shaft out of the motor.

If you notice much of this lateral movement, the motor needs some serious attention, for it to function normally. The next step would be to remove it
from the saw and take it to a motor repair shop and have them analyze it and do the repairs to it, if you are not sure of doing it yourself. When you start removing the motor from the saw, take some pictures, make some diagrams of the electrical wire connections so that you can reference them when it is time to re-install the motor. While at the motor shop, ask them for an estimate on the repairs before authorizing and needed work, it should be considerably less expensive to repair this motor vs. buying a new one, a new one of the same type and size, and hp. probably would cost in the $250.00 to 300.00 price range.

If the problem is the arbor bearings, the entire trunnion assembly (arbor, shaft, blade tilt and elevation mechanism)
would have to be removed to access the bearings in the arbor assembly....this translates to a fair amount of work.
If you need more advice on what and how to do this type of repair, go to OWWM.com site. There are a lot of helpful
knowledgeable people there.

[Knottscott]

While the belt is off, turn the motor on and run it without the belt. If it still shakes, its definitely something in the motor shaft or motor pulley. If it no longer shakes, it's likely belt, arbor or the other pulley.

[mpc]

From the OP's description, I think he's saying the arbor drive pulley is suspect. What I'd check:
1: grab the pulley and try moving it "up and down" and "left and right." If it moves around, the support bearings are worn and need to be replaced. I don't know the specifics of his saw but bearings are almost always "standard" parts - just look for faint numbers stamped into the edge of the bearing and buy one with the same numbers. Getting them in/out may require a press; an automotive machine shop (or a well equipped NAPA) will often do bearing press tasks for just a few bucks - and I'll bet they'll have the replacement bearings too. McMaster-Carr is another source.

2: on many Delta contractor saws the trunnion assembly pivots on a metal dowel about six or seven inches long... the two cast iron "ears" that form the pivot often wear, getting larger in diameter. This leads to slop in the whole trunnion. As a quick check: install a blade normally. With the saw OFF and unplugged, raise the blade almost all the way. Then grab the blade at the very front and try moving it side-to-side. If it moves (other than the blade flexing/bending itself) or if you hear metallic "clicks" then eyeball the whole trunnion assembly and see if it's moving too. If so, odds are the saw has a worn cast-iron trunnion assembly. Replacement of that may cost almost as much as a new saw. A machine shop might be able to drill the holes a little larger - making them 100% round again - and then fit insert bushings/sleeves that'll bring the diameter back to the original value.

3: the arbor itself may be bent. The easiest way to check this is to remove the blade and the drive pulley... then use a magnet mount base to hold a machinist's dial gauge (the same gauge many web sites show for checking blade runout, or distance from the miter slot to the blade, etc. They're not expensive at all and really handy to have) on the pully side of the arbor. Rotate the arbor and see if the dial gauge moves - if so, th earbor is out of round or bent. A few thousands is no big deal, if the runout is more than 0.005 inches though I'd get it fixed. Then move the gauge to the blade side of the arbor and repeat the test.

mpc

[npregion2]

The issue was the arbor drive pulley. When I took it apart the pulley itself was bent. Thank you all. It is great to have a forum to come to with such a wealth of information and everyone willing to help.

Nick