Re: [CAD_CAM_EDM_DRO] Angular Contact Bearings and Ballscrews question

Tom: I can't advise about the lead-screws in a mill or lathe, as I have no
experience with changing or "improving" those arrangements. However, I did a
large X-Y table with some LONG 1.5" dia. ball-screws, and was advised to use
DUAL angular-contact ball bearings, arranged in "opposition" at one end, with
"three bearing-thicknesses of space between the two bearings" in a single
bearing-block. This worked fine, but I have NO clue how "important" any
single detail of any of that was.

Next, I had to build two small application-specific (special-application)
woodworking lathes with a SINGLE spindle-speed (3600 RPM), and was told to
use "Dual Race angular contact ball-bearngs, NOT tapered roller bearings".
Did. Kinda expensive, but Grainger's had those right in the catalog! I was
also told to use a "normal" single-race ABEC-5 bearing at the "left end" of
the spindle, but mounted "normally". This spindle was kinda short (11"? I
forget, now!), and there was no arrangement to "float" that latter bearing,
but all is OK. I have run the machine for hours with no problems. OH! I
was also told to use a "muffin fan" to blow forced air through the headstock
(the motor is 4L-V-belt connected, below) to cool the bearings! They DO warm
up a bit! After thousands of hours, the "permanently lubricated, sealed"
bearings are still just fine, but I kinda wish, somehow, there was some way
to re-lube those, now and then!

The only machine I can recall that had tapered roller-bearings (aside from
"car parts") was an OLD Atlas lathe. Some folks "love" those, but they were
kinda obsolete! I have NO clue if "tapered" is right for any new lathes,
etc. Just no idea. But for high-RPM use, the dual-row angular-contact is
right! Yep! Scho' nuff!

Jan Rowland