I finally got my Bridgeport mill wired up this weekend. The head makes a very loud noise, and I was hoping someone here might recognize the sound and have a good idea of specifically what part needs to be replaced/repaired. There is a short sound clip at the end of this thread you can download to hear the sound. It is actually quite a bit louder, but my microphone is not great.
Mill specifics: 2J vari-speed head, 2 HP motor, early 1980's production, appears to be in very good condition otherwise.
Some observations I have made: The noise is about the same in high and in low gear. It is definitely not a noise coming from the spindle like a bearing, because when in low speed and gear (60 rpm), the frequency of the noise is MUCH higher than the spindle speed. The noise does get slightly louder when changing the vari-speed drive to a higher speed (within the same speed range).
I believe this is a common problem. When I bought the mill, I had the guy power up several mills so I could swap this head for a better one, and they all made about the same noise.
I have bought and read the maintenance manual for this machine. The only reference about noise it mentions is something about an adjustment of a small part that controls the clutch and is by the high/low/neutral lever. It looks like I have to take the head partially apart to get to this.
I have seen some kits on ebay that replace the plastic bushing (part 59 in link below) for the reeve's drive pulleys (the cone shaped pulleys). They claim this could be a cause for noise and vibration. I don't know if this is the problem my machine has or not.
I figure I will have to take the head apart, but I was hoping someone here might have a good idea of what area to look at.
Here is a link to an exploded view of the head. If you think you know where the problem could be, please refer to the drawing numbers they use so we can communicate effectively. You have to click on "Bridgeport Replacement Parts" then "Variable Speed Top Housing Assembly"
Thanks,
Nick