Arvid Jedlicka wrote:
> I've purchased an Asian 3-in-1 drill, mill and lathe. Recommendations
> on the machine's user group suggest that the mill spindle bearings installed
> on the machine be replaced with a higher quality bearing. I have the
> bearing numbers - 32006x, 32007x and 32008x - but when I go to
> someplace like
>
> www.awbearings.com
>
> and see a list of 10 or more manufacturers for each bearing:
>
> Chinese
> Consolidated
> FAG
> GPZ
> Import
> Koyo
> MRC
> NSK
> NTN
> Timken
>
> I have no idea which manufacturer to choose. Any suggestions as to
> "Who makes bearings you can trust?".
>
One indication of which ones to avoid would be to take the numbers
you have to an industrial supply shop, and ask which manufacturers
offer those bearing types and sizes in ABEC 7 grade. Most people are
unaware that there are seven bearing grades, ABEC 1 being the lowest
(and the most commonly used in automotive manufacture, BTW, with
ABEC 7 being the highest grade--those with the highest quality
control and the most precise tolerances). FAG is German, I believe,
NTN, Koyo, NSK are Japanese, while Timken, of course, is US-made.
All of those should have each available in the better grades.
Consider asking for the bearings in the higher grades. ABEC 5 is
probably 50% higher in cost, ABEC 7 approaching 100% of the cost of
the cheapest grade. For your purposes, I'd suggest no less than an
ABEC 3.
If not equipped, I'd also recommend removing the quill and machining
the quill to accept a lip seal, then running the bearings in spindle
oil. I used a Bridgeport copy once that, from new, used greased
bearings and an oil bath above for the quick-change gears. The
spindle bearings wore out under pretty hard use in about eight
months. I did the above, installed ABEC 7 bearings running in
spindle oil, and the spindle bearings were still good when I left
the company five years later.
Hope that helps.
Cheers.
--
Michael D. Porter
Roswell, NM
Never let anyone drive you crazy when you know it's within walking
distance.
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