Bad bearings? Dah Lih circa 1976 Taiwanese

Oh, okay, those are Z bearings instead of ZZ (single vs double-shielded). Normally, drive sleeve bearings are a close slip fit and not a press fit. It sounds like you're right in that if the spacer is too long and the axial play is however much longer the spacer is, then that accounts for the axial play you're seeing. Too bad you can't find the manual; it would help confirm if the bearings are the correct ones.

The quill bearings should be tapered roller bearings and should be light press fits. There should be two preload nuts on top, separated by a tabbed lock washer if yours follows the typical Asian pattern.
 
So I turned the spacer down to be about .005mm shorter than the bearing seats and started on the quill. Does anyone have a similar nut at the end of theirs? I guess I'm going to have to make a pin spanner. Wish I had a mill!
I'm still not sure what the philips head machine screws are for? Pretty sure they are for oiling or greasing the inner quill. There is also a grub screw that has a grub screw inside that turns with the spindle.
20170810_183359.jpg 20170810_183411.jpg 20170810_183429.jpg 20170810_183507.jpg 20170810_183515.jpg 20170810_183613.jpg
 
I'm going to guess that the end cap at the lower end of the spindle threads off and that should expose the lower bearing. A strap wrench should get that off. I would also guess that removing the cover at the top end with a pin spanner will reveal the preload nuts and upper bearing.

Once you get the covers off and press the spindle out of the quill, the function of those screws will become evident.
 
The upper bearings are designed for radial loads. They only keep the upper end of the spindle located radially. The lower bearings are in the quill and are probably tapered roller bearings. They take all the working loads from the spindle, and contain radial and axial runout there. They should be cleaned, lubed with light grease, assembled as clean as possible, and lightly preloaded. Spindle bearings are often a precision grade that has etching marks on them to show the high/low spots, and those need to be properly oriented at installation for best accuracy.
 
That's an odd arrangement a set screw with a Phillips head screw in it, if I'm looking at it correctly.
 
I've had absolutely no luck getting the end off this quill. I made a heavy duty pin wrench but even that is starting to bend. Any suggestions? soak in penetrating oil? heat? I've bashed and gripped it about as forcefully as I'm comfortable with.
20170813_130749.jpg 20170813_130807.jpg 20170813_130823.jpg
 
Well I just broke the wrench that took me 2 hours to make so I'm really at a loss.
 
Are you sure all pins are out? While unlikely, what about that hex headed screw on the end of the cap?

If all else fails, you might try some gentle warming with a torch.
 
Back
Top