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madman
12-21-2006, 10:54 AM
Man cant believe my Luck. I just got home anyesterday and the UPS trucks sittin there in fronta the house. I just caught the guy with my $100 dollar box of replacement parts for my broken Bridgeport Mill. Anyways brokerage tax were another 57 dollars. HM To make long story really short. I installed new parts now the mill quill feels notchy going up and down. With the gear shaft out the quill is in good shape moves nice and smooth. Whats going on. I feel like a tretarded (mentally challenged i meant sorry) machhine repairman. Thanx

rkepler
12-21-2006, 11:49 AM
Is it a 'fast notchy' or a 'slow notchy'? There's not a lot of gear teeth on the quill, so if you feel it a couple of times per handle revolution it's likely there. If it's a lot more frequent it might be the clutch in the power feed. I'm extrapolating a bit from a recent problem on my Lagun that might be described in the same way.

Wirecutter
12-21-2006, 12:41 PM
Mike -
I've had similar issues with my Bridgeport. I'd like to help if I can. I've got a step-pulley J head.

If you remove any collet, and then the drawbar, and still get the notchy feeling, consider the following.

(I'm consulting a parts list and exploded diagram) There's a bearing locknut on the top of the spindle bull gear assembly. It's locked down with one of those lock washers with a bunch of tabs around the peremeter, and one of the tabs gets bent down to engage a notch in the locknut to keep it from rotating.

If, for example (don't ask me how I know), the spindle speed is shifted from low to high range when the spindle hasn't quite come to a complete stop, that locknut can loosen. It's very hard to explain the parts that come in conflict, but basically parts of both the high speed and low speed drivetrain are trying to engage at the same time. (That lever next to the spindle brake? It's no longer lifting the pulley high enough to clear the "splined gear hub.") The bearing locknut has to be snugged up, but not so much that the bearings bind. It's a little tricky to get this just right on my machine, but it's important. To get to this, I remove the motor and the top part of the upper housing and work on it on a table.

Is this any help?

-Mark

Scishopguy
12-21-2006, 05:17 PM
Hi guys,

I had a similar problem with my J head, step pully Bridgeport and discovered that the two pins that the shift lever ring (on top of the head) rides up on get loose. The threads back out and let the assembly sag, causing interference with the back gear spline. I just keep an eye on them and tighten them up every day. I hope this is of some help.