I too get frustrated with electrical fixtures. I got some boxes once and there three different screw drivers required. In frustration I asked a pal with an electrical red seal certificate and he said, "what do you expect, it's a four year apprenticeship ?"
Since the bearings and races looked pretty good, and after @RobinHood post, I decided to just clean, lube and reinstall the spindle. I decided to just use grease, Shell Gadus S2 V100-2 (NLGI 2, Lithium grease, 100cSt viscosity).
I slowly tightened the preload nut until the spindle would not rotate, and then backed it off a smidgen. The spindle turned freely with resistance - due to the grease. I then went to install the motor pulley, but it didn't have a key slot. It had the set screw bite into the key way of the old motor. This won't do. And since I don't have broaches, or a shaper, or a slotting attachment, I went old school. I put the pulley in the milling machine, and used a boring bar with a 3/16" hss bit I ground. Indicated center, put a band clamp around the mill spindle and column to prevent rotation, and using the quill for the stroke, took 0.005" passes until I got to the proper depth. The pulley is aluminium so it went quickly.
This morning I decided to run the spindle and try to measure bearing temperatures. Spindle speed is 3450 rpm. After a bunch of reading to find what the optimal operating bearing temperature is supposed to be. Apparently on several sources, says to keep the temperatures below 150-160°F.
So using an infrared gun, I took measurements at the end of spindle housing opposite the bearing location. Every 5 minutes. After more than an hour, the temperatures seemed to stabilize at 138°F. So I think we're good. Have a look at the picture, it has the results of the test.
I now have to clean up the table, and do a bunch of other minor stuff and we should be ready to grind our first cutter. Probably woodruff key cutters.
I should have measured after the test. But right now, cold (room temp), runout is 3 tenths. But have a look at the second picture. Somebody in it's past history grabbed the spindle with a pair of pliers, so measuring it can be misleading. And there is half a tenth of play, where before it was 2.5 thou' play.
When I got the Clarkson, it didn't have the ball crank for raising and lowering the spindle head. So I ordered a cast iron hand wheel from Ebay in the US. But the hub was threaded for a size larger than the diameter of the elevation spindle. So I bored it out, made a steel plug and press fit it in. Then drilled and reamed to 0.500". I also had to install a set screw. And, the hand wheel didn't come with a handle. So I made one from some piece of steel lying in the bin.
Today, I installed the DC link choke. Here is the explanation of what it is:
MTE’s DC LINK CHOKES, also referred to as DC line chokes or inductor chokes, are an economical means of filtering and controlling the DC bus voltage and current in a variable speed drive/inverter. They help reduce AC input line current harmonic distortion while absorbing DC bus voltage spikes. Link Chokes add protection and filtering but should not be considered a direct alternative to AC input or output reactors.
MTE’s DC LINK CHOKES offer the advantage of maximizing the circuit inductance for power quality reasons, but without causing an AC input line voltage drop. Link Chokes can be used individually, typically on the positive DC bus, or in pairs with one each on both the positive and negative bus. When two DC Link Chokes are used on the bus, the inductance is additive. You will need twice as much inductance on the DC bus as used on the AC input (per phase) to accomplish the same performance experienced with AC input reactors. For best performance combine the use of both an AC input reactor and a DC Link Choke.
I'll be using the VFD to vary the spindle speeds, depending on which grinding wheel I'll be using. The motor to spindle pully ratio is around 2:1, but I used the laser gun to determine actual spindle speed at 60hz. It is 3685 rpm. My VFD, and I'm sure others as well, has a function where it will use the output frequency and multiply it by any constant. So, since my spindle speed is 3685 rpm@ 60hz, the ratio is 61.42. When I use that number as the constant, I can now see on the VFD display the rpm of the spindle at any frequency. Easy peasy! No need for rotary magnetic sensors. Of course this only works at one given gear or pully ratio. I can't fully utilize this method effectively on the milling machine or lathe since I'm always changing gearing.