I repeated the procedure with the top wheel on and a band in place until the top wheel was balanced. The saw was running very smoothly and felt stable and solid. Done! Now running the saw with the lower wheel, I noticed less vibration than before the balancing, and again a wee incremental bit of additional vibration above just running the motor and shaft, but it was still only barely discernable, and a nickel stood on edge on the table (a very common vibration benchmark) was nearly undisturbed, so I was satisfied. I drilled a couple light holes, retested, and it was equal all around the wheel. 0045, indicating that the lower wheel was quite balanced. This is all done with the tire on the wheel (if you need a new tire, replace it before doing this procedure!).
![delta rockwell table saw bearings delta rockwell table saw bearings](https://i.ytimg.com/vi/fYX9TMj_Bk4/maxresdefault.jpg)
This indicates the heavy spot of the wheel. Then I found the largest reading and experimented placing the clip to either side to find the maximum vibration. Then I clipped on a large metal paper clip to the wheel in a random spot, recorded the amount of vibration by reading the dial on the dial indicator, then moved the clip 90 degrees and so on, getting a vibration reading all around the wheel at 4 cardinal locatioins. You set the dial indicator on a solid piece of equipment (in my case, the infeed table of my jointer), and set the dial onto the table or some other surface of the machine. Here's where I started to splurge, by purchasing a dial indicator and magnetic base, which I've always wanted anyway.
Delta rockwell table saw bearings how to#
However, from the Old Woodworking Machines site, I learned how to dynamically balance the wheels while they're in place on the saw. That was from my first attempt to statically balance the upper wheel, which was actually quite successful (and illustrated how hopelessly unbalanced it was to start with). You can see from the pictures above that I had drilled out the rim of one wheel (a LOT). Satisfied, it was time for the big ticket item of balancing the wheels. The stock bearings were NTN, and it only costs $2 each to move up to better quality bearings from SKF or whateve your local bearing house carries: While I was at it, I tapped out the upper wheel bearing and replaced them with new bearings. I got tired of handling the wheels, which have sharp ridges from the casting, so I took after both wheels with a variety of bastard files to smooth them out a bit. I had to sand a couple burrs back with 150 sandpaper that I made being careless removing the first bearing from the shaft, then as a general remedy I lightly touched up the entire shaft with a piece of worn scotchbrite. The tolerances between the shaft and inner ring of the bearings is extremely tight, so any little nick, burr, or dirty spot on the shaft creates trouble fitting the bearing to the shaft. I cleaned up the bearing casting with worn scotchbrite. These bearings have a snug friction fit, but do not require any tools to remove/replace. Then I re-bolted the saw to the stand, and moved on to the next moving part, namely the lower wheel, shaft, and bearings. I could feel and hear the difference - much less vibration throughout the saw. This did 3 things: took up any slight "slop" in the base to mount connection, deleted the harmonic buzz, and provided a wee bit of isolation. So I loosened the motor mount bolts and slid some pipe insulation between the motor frame and mounts (taking a trick from building computers in which I never solid-mount a moving part to the case without isolation). However, the slight motor vibration could be felt throughout the stand and saw and you could hear a harmonic buzz. With the belt off and no sheave (the thing that looks like a pulley wheel) on the shaft, the motor ran very smoothly.
![delta rockwell table saw bearings delta rockwell table saw bearings](http://ozarktoolmanuals.com/wp-content/uploads/2015/10/0245.jpeg)
The motor shaft spun very freely, with no wobble and play, so it seemed like the motor bearings were solid.
![delta rockwell table saw bearings delta rockwell table saw bearings](https://i.ytimg.com/vi/Dj1NQJgrHTA/hqdefault.jpg)
Now that I had a stable platform to work from, I began looking for vibration in every moving part, starting with the motor. With only the motor and lower wheel turning, I could tell a difference.