Bridgeport series 1 2hp mill Question??

[Mike8623]

OK guys got the above mill real happy with it but have a problem. when milling and starting to take a cut (pass) my end mill will rise up about .020 when starting the cut . I figure it must be a bearing in the head or something of sorts is wore out and enabling the end mill to rise up a tad before taking a cut. Any ideas what might be wrong or what may be worn out. Do I need to rebuild my head?

 

[4ssss]

Do you have the quill locked?

 

[Silverbullet]

Could be a bearing adjustment or like 4sss said is the quill clamp tight and locked. Is the collet tight and the right size for the cutter.

 

[Technical Ted]

Put an empty tool holder in the spindle an lightly pry up on the bottom of it with a bar without ruining the motor. See if you can tell where or what is moving.

 

[Mike8623]

You know I don't think the quill has been locked. I just now locked the quill and I can push the spindle up and down about an 1/8 of an inch.....so there is play in the spindle up and down. anyone with an idea on what may be worn inside?

 

[JimDawson]

You know I don't think the quill has been locked. I just now locked the quill and I can push the spindle up and down about an 1/8 of an inch.....so there is play in the spindle up and down. anyone with an idea on what may be worn inside?

That's a lot of play, I would normally expect zero play with the quill locked. There is a nut on top of the spindle that might be loose. You need to drop the quill out to get to it.

 

[Technical Ted]

So it's moving inside the head where you can't see or is the whole head moving up and down? This is a long shot, but make sure your 3 nodding lock bolts are good and snug.

Good luck,
Ted

 

[Mike8623]

Ok guys looked a lot closer this morning. The spindle is moving up and down in the quill. I took a measurement as best I could with my calipers and it looks to be about .070 movement of the spindle inside the quill with the quill locked down. Has anyone had this happen before and offer an explanation. I'm assuming I will have to take the quill/spindle out of the mill and troubleshoot and repair it. If I'm doing this should I just do the entire head or what.

 

[Technical Ted]

YouTube can be your friend! Check out this video. No need to do a complete head rebuild for a spindle problem IMO.

Good luck,
Ted

 

[Technical Ted]

Also, check that the nose piece is adjusted properly. This is the "end cap" that has a set screw on the back side of it on the bottom of the quill. If that is not adjusted and holding the spindle bearings in place, it can allow the bearings inside to move up and down and give you the play you describe.

Just a thought and something to check before you tear everything apart... Don't over tighten the set screw as it can cause the quill to bind in the house in the upper position.

Ted