IH - RF45 bearings
Hi guys,
While working with my machine today the lower spindle bearing started to heat up pretty good. I was on borrowed time with the belt conversion running 6500 rpm and stock tapered roller bearings.
My question is about angular contact bearings for the spindle. It is my understanding that in a perfect world one would have a double set of AC bearings at the bottom of the spindle with a single regular bearing at the top. This eliminate the thermal expansion messing with the pre load I guess.
So on our less then perfect machines (RF-45 types) do you simply replace the tapered roller bearings with AC bearing (one on top and one on bottom) and get the pre load as close as you can? Or have you guys been machining out the lower spindle for a double set of bearings at the bottom?
I am looking at:
7207BMU Nachi Angular Contact Bearing 35x72x17 Brass Cage C3 Japan Ball Bearings... $40.00 each.
Or
7207 Nachi Angular Contact Bearing Steel Cage C3 Japan 35x72x17 Ball Bearings... $23.00 each.
Thank you for your help.
Kelly
www.finescale360.com