PRR, Here may
be some useful information...
On 1/29/2025 10:13 AM, Pierre-Raymond
Rondelle via groups.io wrote:
Sorry, I wrote the message on the web page and i sent it too
quickly. Here's it again :
Hi, I've some trouble adjusting the clearance of the
headstock bearings on my lathe. It's a WBL210 Weiss lathe ; max
Dia 200mm, 300mm between centers, roughly a 8x12" lathe of the
same design as the 7x12 ones.
?
The surface finish was not as smooth as expected: even with
shallow pass with slow motion. It was looking like a ~2mm pitch
thread with a very low roughness pretty lower than 0.1mm.
Probably the leadscrew pitch amplified by the gear train and
some play in between the spindle bearings.
Tightening the nut at the end of the
arbor improved the situation but I couldn't manage to
tighten it farther. The bearings seemed to be blocked by
something. The drawing doesn't show any obstacle however.
the bearings are 30206, tapered roller type.
There are several gears and spacers
between the 2 bearings that have "STACKED TOGETHER" to create
a "SOLID" column of material to be squeezed by the adjusting
nut.? You have to thin down one of the spacers due to the
different dimensions of the new bearings.
On to the other hand, 6 months ago I attempted to
troubleshoot the spindle of my milling machine (model? VM18L
from the same manufacturer), ending by tuning the deep groove
bearing clearances. It went the same way as the lathe. But since
I didn't notice any discrepancy, I let it as it was and
remounted the spindle.
Several times, I've replaced tapered
bearings on the wheel hubs of my cars without any extracting
issues. They went well adjusted but not needing any great
force to get them.
Your wheel bearings do not have a solid
spacer between the inner and outer wheel bearings, the lathe
does by the accumulation of the 2-speed drive gears and spacers,(do you have a 2-speed lever on the back or
direct drive)
I assume that the accuracy of a machine spindle being greater
than a car's hub one, leads to a tighter adjustment. But, does
it really need an extractor or is that a specificity of this
manufacturer or even a bad quality level ?
I found some clues on
.
The bearings are 6206 deep groove or 7206 angular contact ones.
The procedure uses both an extractor or a press but doesn't
specify the force. I'm puzzled by the fact that I can't manage to
tighten a bit more the nut because, normally, the external bearing
should slide against the shaft otherwise it should be impossible
to adjust the clearance.
Perhaps search YouTube for "mini lathe
angular contact bearing" and reveal this -->?
?
<--. Maybe 'click it even'. Good luck on your final
answers.
?
Please, may a specialist bring some light over all of this and/or
provide other URL to relevant information ?
TIA
