DoN. Nichols wrote:
On 2016-12-06, Christopher Tidy wrote:
Hi folks,

I need an example for an article. Can anyone think of a modern product
which uses plain bearings in a demanding application? I'm not talking
about the extremes (like dental drills and steam turbines), but more
common applications such as supporting lathe spindles and engine
crankshafts. It used to be common to have plain bearings in these
machines, and some were incredibly durable, but I haven't seen any in a
new product for a long time. Are there any examples, or have they been
entirely displaced by standardised ball and roller bearings?

Well ... how old do you accept as "modern"?

I've got a nice Cameron Precision sensitive drill press, which I
got new sometime in the 1970s which has plain bearings on the spindle.
It goes up to pretty high RPMs. The spindle ends in a JT-0 and mine
came with a 1/8" Albrecht chuck on it. to give an idea of size.)

Got one of those too. They just discontinued the classic looking model for
a newer design. My guess is they ran out of castings or motor parts from
decades ago. While way newer than yours, it has plain bearings as well.
With a little practice I was able to drill through the widest part of a
brass key for about a 30x width hole with good straightness. There's no
play that I can measure, and they claim speeds up to 30,000 RPM are OK.
Small bearings can run fast, so there probably isn't any real sorcery
behind their bearings other than there's some hand fitting going on at the
factory where they take out all the play. The original motors are real
screwy, so there's no loss if they ditched those for something better,
even if it doesn't match the look of the original.

And -- as far as I can tell, they still use the plain bearings.
(they look like sintered bronze style, not hand-scraped bearings.

Ehre is the page which shows mine as the first photo, excep that
mine does not have the clear plastic belt cover.

http://cameronmicrodrillpress.com/sensitive-manual-micro-drill-presses/

Scroll down far enough and there is a link for contacting for
questions -- so you could verify whether they still use the same
bearings that way.

Enjoy,
DoN.