Milling machine spindle

Perhaps a dumb question, but is there any reason why the spindle of a vertical milling machine should be able to operate in the reverse direction?
For horizontal ones, it can be useful - but for vertical ones?
Ta,
-- Peter Fairbrother
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Peter,
No real reason why not but do look at how the bearings are retained, you may find that there are nuts on the spindles which could undo through running in the opposite direction.
Martin P

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campingstoveman wrote:

That's kinda the potential problem - I've just replaced the spindle on my BCA jig borer/milling machine with an ER 25 spindle, and if I tried to drive it the other way it might come apart :(
But if there's no reason why I might want to drive it the other way, then everything's okay :)
I can't see why I might want to, but - do the spindles of vertical milling machines generally operate in both directions?
-- Peter Fairbrother

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Peter Fairbrother wrote:

I've got some mills that need to rotate in the other direction. Works for me!
Bob
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Hi All, I, too, have some end mills(1/2"x2") that are LH, could not use them if mill did not go backwards. Mind you, being backward is how I have been described, so seems apt. T.W.
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a
direction?
When you take off too much material by mistake, just reverse the spindle and put it back on....... ok I'll get my hat!
AWEM
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On Sat, 08 Nov 2008 20:45:58 +0000, Peter Fairbrother

Certainly.....I frequently use my machine for tapping, and withdraw by simply switching into reverse.
--
Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"

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On a full size industrial machine you need to run the horizontal spindle in a certain direction sometimes.When fitting the vertical head the spindle may go the wrong way so you have to be able to reverse the main spindle.
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There was a design for a speed increaser (for drilling tiny holes) in MEW a few years ago which involved a sun + planet gear train; the version described (there was IIRC some brief mention of how this could be avoided with a more complicated arrangement) reversed the rotation, which would require the milling machine to be capable of reverse running.
David
--
David Littlewood

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- in issue 101, if anyone is interested; I just by coincidence happened to be looking at something else in the same issue this afternoon.

--
David Littlewood

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writes

And of course on a Bridgeport engaging the back-gear for slow spindle speeds reverses the spindle, so you have to also reverse the motor to make it go forward.
Don Young (USA)
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