View Full Version : Fray rebuild Update and Question. Pics!!!
01-25-2008, 06:44 PM
First the question. I am about to replace the Knee leadscrew and Thrust Washer. Should these be Greased or Oiled? I have cleaned all the grease from all the other passages and Zerks so that they can be oiled in future. Just not sure about the knee though.
This is a Bridgeport round column Base.
As pulled apart
Thrust Race cleaned up.
Knee coming Off
Ready to go back on.
01-25-2008, 07:18 PM
Your pictures tell the story...that looks like grease with lots of imbedded swarf....which becomes a bit like lapping compound.
Oil (even oil that has thickened) can be washed out with more oil, allowing swarf to flow out. Unfortunately, the inside of a Bridgeport knee is a gathering place for swarf as the back side of the knee (between the knee and column has some openings. Even though the plates on top help keep it from dropping in that way, these holes on the back side manage to catch it. Mine came out of a tool company and must have had 5# of swarf inside the knee.
I think reaching up underneath to hit the bronze knee screw nut with some oil from time to time would be a good idea. Mine is much newer and has a one shot oiler, but even with that, this is one place they do not lube automatically.
The newer BP's all use a sealed bearing inside the knee, which should help with the swarf problem
P.S. your pictures make the case for taking apart a newly acquired piece of machinery...a position I have advocated here before. I know others here recommend against it, but you just don't know how much grit you are grinding in the works for years to come if you don't pull it apart.
01-25-2008, 07:29 PM
Thanks Paul, here is a pic of the swarf in the bevel gears when pulled down.
The "Dog Bone" can be oiled by aligning a hole in the table with a hole in the saddle designed for this purpose.