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Bridgeport spindle runout

Hi all, I am a little concerned about my series 1 Bridgeport's runout. Taking a measure on the spindle nose I get a reading of .0005 which seems pretty good to me but when I use a 1 1\2 toolholder the runput is .002 and when I use a slitting or slotting saw that has a 4" diameter it sounds like only 3 or 4 teeth on the high side of the blade are doing all the cutting. Is this common or should there be zero tolerence on the spinlde and I should consider getting it rebuilt? Thanks

Reply to
12 BlackNails
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Just to clarify, are you placing the indicator on the outside of the spindle nose or on the conical inside surface?

Have you checked that conical inside surface for damage? Get in there with a magnifying glass (turn the head if necessary) and examine carefully.

Reply to
Carmine Castiglia

Coupla things. First, try putting that 1 1/2 toolholder in again, but only tighten the drawbar finger tight just to keep it from falling out. Put your DTI on it again and find the spot of highest runout. Now take a chunk of lead or a soft hammer and try to tap it in. You can often make a correction of at least .001" that way. You can also check that tool's taper isn't scored or dirty. You can also blue it up and test to see if it's bearing properly on your spindle taper.

On the slitting saw, it is very hard to sharpen those saws so they cut evenly. A savvy old machinist once told me "don't worry they always make that skritch-skritch sound".

Grant Erwin Kirkland, Washington

12 BlackNails wrote:

Reply to
Grant Erwin

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