Bridgeport quill to head clearance?

I'm fixing up a Bridgeport head to replace the Millport head on my CNC
knee mill. Or trying to see if this head is worth fixing up to replace
the Millport head. What sort of clearance should I have between the
quill and head? Near as I can measure, I've got about .001 give or take
a few tenths. Dry, that's enough to cause some finish chatter I'm sure,
but with oil in there, might that be OK?
Reason for the swap is downtime, can't afford it. Got the BP head cheap
enough to sit on it for a year before Millport head noises prompted me
to get moving on this.
Thanks,
Jon
Reply to
Jon Anderson
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The clearance is enough that I wouldn't spend too much time on that head without actually trying it out. I've seen the number for the proper clearance and it's very small-a few tenths perhaps?
Ned Simmons
Reply to
Ned Simmons
That sounds more like it. I decided to invest a bit of time and bolted the casting to my mill table, set a mag base on the casting and the indicator on the quill. Using a 2' long AL bar, I could move the quill that .001 fore and aft. I had a full oil film, so it wouldn't just pop over .001, but it would move. Sigh...
Thanks,
Jon
Reply to
Jon Anderson
You could have the head rebuilt or trade it in.
See
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They fix your problem by hard chroming the quill and then grind back to size. I have had one of their rebuilt mills for 10 years and it was like new when received.
Randy
Reply to
R. O'Brian
Randy,
Thanks for that, I emailed and asked for quote on refitting the quill only.
Jon
Reply to
Jon Anderson

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