Re: Spindle bearings and lubrication
Martin,
The bearings in the spindle get GREASE only and in a limited amount. Don't pack them like we used to for front wheel bearings on autos! You don't need spindle oil (nor do you want it as it will wash the grease out......Ask me how I know).
IIRC the fill rate is about 25% and then after you reassemble the quill, you need to run in the bearings. What I did was to chuck it up in the lathe. I maxed out at about 2000 rpm before I reinstalled the quill in the mill and continued on up to my max of 4000 rpm. Below is the recommendations that I found:
Typical run in for spindles is a starting point of about 400 rpm,
up to max in 500 rpm increments, in steps of 30 - 45 minutes.
Check housings for excessive heat as you go.
Then reverse and do it over!
Watch temperature. If it gets hot, stop let cool and do over.
Above is the procedure I followed and after I was done, I found the info below. During run in, I monitored the temperature with an IR non contact unit and kept track of the temps.
The Fafnir Superprecision Machine Tool Bearing catalog suggests that with optimal design,
bearings running synthetic low friction grease ought to be able to run about 20 degrees C
over ambient or about 40 degrees F. In fact, they suggest a proper break-in procedure temperature of 130 degrees F.
involves running the spindle until it reaches 150 degrees F, turning it off to cool, and repeating the cycle
until the spindle stabilizes at 130 degrees F or lower operating temp.
The ideal equilibrium operating temperature is 95 to 115 degrees F. Maximum temperatures should not exceed
170 degrees F. Timken's published specs for tapered roller bearings, including bearing life specs, assume an operating
temperature of 130 degrees F.
HTH
OH as an afterthought, you mentioned one shot etc. I use way oil in my one shot to lube the ways, ball screws and where the quill runs in the head casing on my RF31.
Art
AKA Country Bubba (Older Than Dirt)