Colchester Master 2500 spindle bearing issue

[Dave123]

I have a Colchester Master 2500 (likely mfg'd in the mid seventies), new to me machine.

Upon start up the cutting finish was terrible.
The runout at the face of the nose cam is .002"

The bearings are not overly noisy when running.

I checked for forward movement of the spindle with a prybar and it does move about .060" then retracts with the force of the rear bearing springs.
The static position from the front of the housing to the rear of the cam nose is .150"

If I tap the spindle to the rear with a rubber mallet it will move another .002"-.003", which seems to settle the runout issue down, now it has .0002" at the face of the nose cam.

To me it seems the springs at the rear bearing are not causing the spindle to retract? Its difficult to know how much force the springs should have?

Reading some of the posts here on this topic some say that a common procedure is to remove some of the rear bearing preload springs?

It is obvious that someone has had this apart at some time.

Any advice would be appreciated.

Dave E

 

[mark costello]

Before I found much information about My Clausing Colchester 15"x50" I was having taper issues that I could not find a solution to. I tore out the spindle and found out 4 springs (out of 24 holes) missing. I ordered 24 new ones -expensive- to make sure of what I had. It took the taper from .012 in 2 inches to .002. Then found out it was supposed to be too much pressure, no overheating present. Then another machine repairer said They had to do the same thing to fix theirs. Been that way for about 4-5 years now with many hours run time.