[victorgallas]

Hi,

We recently acquired an ACRA Mill that uses essentially a bridgeport clone head.
While getting the machine up and running I noticed that the quill does not go up all the way smoothly. About an inch from being all the way to the top the quill binds and essentially you need to force the handle up really hard to make it all the way in. then if you let it sit there, you need to put good force to let it move down. So obviously is binding.

I have read about the quill deformation issue at the bearing retainer cap at the quill end causing troubles. I already removed the set screw all the way and still binds. Then I tried to remove the bearing cap and it will not move at all. I think whoever serviced this before completely over-tighten it.
My next try will be PB Blast then maybe just a little heat with a heat gun.
I also tried to use a three-foot pipe wrench and nothing. I am aware this will damage the cap itself, and I am planning to buy a new one now.
I am also wondering if the quill could be binding going all the way up due to some crud build up at the top part of the head. i am planning to remove the top section next and just have the quill on its housing to diagnose things better. The auto-feed mechanism is pretty dirty and I have started to remove it to clean it all up, including the shaft to move the quill up and down.
Just to confirm, this bearing cap at the quill nose is not reverse treads, correct?

But I wanted to ask if anyone has experience a binding issue and what was your solution?

Also any tips to remove the bearing cap, please let me know. its become a difficult attempt here so far . I made sure to only force the cap off with the quill into the head as much as possible in order to avoid bending the quill itself. O and to clarify, I did try to use the correct pin wrench onto the cap, with no luck...

[mactec54]

victorgallas

It has a Left Hand thread, you have been making it tighter, You also can not use a pipe wrench on something like this, but I guess that is to late now

What makes the quill tight sometimes, is the 4 bolts on the front of the Quill housing they may have been over tightened

The spindle bearing retaining nut should be tight, this preloads the bearings, & should always be torqued up tight

[victorgallas]

Hey,

Thank you very much for the reply. I feel like the ultimate noob here. So my apologies above all.
i am also upset with myself that I didnt look up before if these were left hand or now.
Well, I will order a new nose cap and then take it apart and do it correctly.
Once again, thank you for the reply.

Is there a good torque value recommended to use for the bearing installation? I am assuming you dont want to tighten to much to the point of deforming the quill?
Either way. I really appreciate the reply. once I can get back to the machine, i will report the outcome.

Thanks

VH