Cooked Eccentric Bearings

[bainin]

Well-

As part of my XMAS gift to myself ... I purchased new V Belts for my SS. The ones I had, came with the used tool, so I didn't have any
sense of how old they were beyond knowing that the PowerPro upgrade occurred in 2012.

I had noticed some black dust on the head of the motor, which I assumed was coming from the belt...so it made sense to replace and retune.

Maybe you can see the dust in this pic-directly under the belt label "522610" on the motor case.

beltdust.jpg (102 KiB) Viewed 3375 times

Anyways- I had pulled the eccentric out during the belt change process and bumped it on the table...and discovered alot more black dust

eccentricdust.jpg (89.82 KiB) Viewed 3375 times

Hmmm- ok-lets pull the eccentric bushing off and have a look at those bearings !

bearingleft.jpg (129.99 KiB) Viewed 3375 times

The inner bearing (one to the left) could be shifted left/right...not sure it can be seen in these 2 pics but clearly it was not held
fast to the shaft.

bearingright.jpg (131.63 KiB) Viewed 3375 times

Alot of smoo on the bearing surfaces as well...both bearings had seen better days.

Luckily I had a backup eccentric assembly and replaced this one.

I was able to pull the right hand bearing off using a bearing puller (removed to right side)
The left hand bearing exploded when I tried this pulling it to the right side - after it was gone, it seems it would need to be pulled
to the left side-though im not 100% sure on this as I exploded it before trying and after the bearing was out of the way, I was unable to find a way
to remove the belt raceway from the black shaft itself.

After retuning, a few of the characteristic knocks I have gotten used to have gone away.

On the retuning, one thing i noticed was the motor tilt seemed off to the eccentric. I think I've read somewhere that the gap on the 4 motor mounts should be fairly similar in gap. Here is a pic of how I found the gaps.

I squared these up first by setting a fixed gap with a washer, and then tuning all 4 together from there.

motorgaps.jpg (54.49 KiB) Viewed 3375 times

b

[DLB]

Idler Bearings - The pulley has to come off to get the 'left' or inner bearing off the shaft. One forum member had success with this that I know of. IIRC he used heat on the pulley to expand it and a bearing splitter to pull it. Fortunate that you had a spare, this is also one of the few PowerPro parts that I keep a spare for. I've noted before that the Idler gets quite hot, especially at higher speeds. The idler runs 1.6X main spindle speed, so as high as 16K RPM, but it doesn't have to run that fast to get pretty hot. I don't love this version of Idler bearings. This would have been the last thing I'd consider keeping a spare for on the older machines with the 'water pump' idler bearing.

Motor Tilt - I had my PowerPro motor tilted like that once too. I had followed the book procedure for belt alignment, and that is where I ended up. That's no good. Two wrongs trying to make a right. I started over with the simple idea that the three rotating shafts should be parallel to one another and the belts should run perpendicular to the shafts. So I used the tilt only to make the motor shaft parallel to the Idler. That made the belt alignment in the book off by about half the width of the pulley. I ended up altering my motor mounts a bit to get everything where I wanted it, but am happy with the result. IIRC there are some setscrews that allow the motor to slide in the motor mounts but I was maxed out and wanting the motor pulley to go a bit farther to line up with the Idler pulley. So I had to cut some relief on the mounts to allow it to slide to the correct position. I think the interference was with the fan housing. The belts do run a bit cooler when properly aligned, which means it is easier on everything.

- David