1. Home
  2. ⏣ General Metalworking
  3. Anybody know Bridgeport power feeds?

Anybody know Bridgeport power feeds?

The power feed on my Bridgeport mill has started making a bad noise when moving in one direction. The mill and power feed I bought new in

1981 and the power feed is the stock factory installed Bridgeport brand power feed. When moving in one direction the power feed sounds like it always has but when moving in the other it sounds like badly meshing miter gears. Which is probably what the noise is. Maybe a gear has become loose on its shaft and in one direction sounds good because it is being pushed against some sort of stop which keeps it properly engaged. But when the gear is spinning in the opposite direction it moves out of proper engagement. Anyhow, before I take the drive apart it would be nice to know if there is anything else I should be looking for. Anybody know? Thanks, Eric
Reply to
etpm
Loading thread data ...

How about checking whether the leadscrew has a bit of end play. If it moves, it carries its gear with it. Likely the bearings at the end of the table just before the power feed and the crank.

Good Luck, DoN.

Reply to
DoN. Nichols

Thanks DoN, I'll take a look at that first once the cover is removed. Eric

Reply to
etpm

Bridgports use a preloaded pair of bearings at the left end of the screw to handle the screw's thrust. The bearing on the right (presumably where the power feed is mounted) floats axially.

Many clones (including my Supermax) have a single bearing at each end with the preload carried by tension in the screw. The Bridgeport arrangement is more reliable.

The Servo brand power feeds rely on the screw to maintain the position of the miter gear. Not sure if this is true of Bridgeport's feeds. I have a ca. 1981 BP manual with an exploded parts diagram, and it looks as though the miter gear's axial position is independent of the screw, but it's not entirely clear.

Reply to
Ned Simmons

Thanks Everyone for your replies. I just finished the fix. The big miter gear had backed off a tiny amount. I guess that's OK after 37 years of use. Like other folks I had added a drain hole to the drive. I was truly surprised to find no drain hole for the drive gearbox. Having to let the oil drain out around the cover is stupid. Eric

Reply to
etpm

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.