Horizontal Mill Spindle Direction?

Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.

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JPar
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Horizontal Mill Spindle Direction?

Post by JPar » Fri Oct 27, 2017 9:56 pm

I hope you'll all forgive me for this stupid newbie question. I'm ready to wire up the horizontal spindle motor on my Rockwell mill, and I'm wondering which direction is considered the "forward" direction for the spindle. Clockwise, or counter-clockwise as viewed from the table side of the machine?
John

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wlw-19958
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Re: Horizontal Mill Spindle Direction?

Post by wlw-19958 » Fri Oct 27, 2017 10:21 pm

Hi There,

"Forward" is generally for right-hand cutters. That is
counter-clockwise as viewed from the table looking
up at the spindle.

Good Luck!
-Blue Chips-
Webb

Harold_V
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Re: Horizontal Mill Spindle Direction?

Post by Harold_V » Sat Oct 28, 2017 1:39 am

For a horizontal, assume you have a drill (or an end mill, as described by Webb) in the spindle. The proper direction of rotation for either of them would be considered forward for the spindle. Standing in front of the machine, the direction of rotation would be observed as contrary clockerty-wise (thanks, Festus!)

H
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John Hasler
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Re: Horizontal Mill Spindle Direction?

Post by John Hasler » Sat Oct 28, 2017 8:28 am

For any kind of machine think about which way would be forward for the spindle were it on a lathe.

earlgo
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Re: Horizontal Mill Spindle Direction?

Post by earlgo » Sat Oct 28, 2017 9:22 am

If you are only going to use arbor mounted cutting 'wheels' or fly cutters,it makes no difference as the cutters can be mounted on the arbor either way. But you would be limiting yourself immeasurably if you do that. It would be best to have the arbor spin as suggested above, because then you can use end mill holders and drill chucks and do a great number of things that aren't possible with a spindle turning in the 'wrong' direction. I use my horizontal with an end mill far more than with an arbor mounted cutter. But then again, I don't have a vertical mill.
Angle cut.JPG
Angle cut with a standard end mill
--earlgo
Before you do anything, you must do something else first. - Washington's principle.

JPar
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Re: Horizontal Mill Spindle Direction?

Post by JPar » Sat Oct 28, 2017 11:20 am

Thanks everyone. Counter-clockwise makes sense.
John

johnfreese
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Re: Horizontal Mill Spindle Direction?

Post by johnfreese » Sat Oct 28, 2017 4:09 pm

If you have milling cutters that mount on an arbor you can mount them either to cut in the CW direction or the CCW direction. I believe it is customary to mount them to cut CCW just as your endmill does. No reason they wouldn't cutting CW and feeding the opposite direction.

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wlw-19958
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Re: Horizontal Mill Spindle Direction?

Post by wlw-19958 » Sat Oct 28, 2017 4:57 pm

Hi There,

Although horizontal milling cutters can be mounted on
the arbor either way, the direction is dependent on the
threads on the arbor. You want the cutting forces to
tighten the nut and not loosen it. That means, right-
hand threaded arbors should be used for right-hand
cutting (counter-clockwise) and vise-versa for left-hand.

Good Luck!
-Blue Chips-
Webb

Harold_V
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Re: Horizontal Mill Spindle Direction?

Post by Harold_V » Sun Oct 29, 2017 1:56 am

johnfreese wrote:If you have milling cutters that mount on an arbor you can mount them either to cut in the CW direction or the CCW direction. I believe it is customary to mount them to cut CCW just as your endmill does. No reason they wouldn't cutting CW and feeding the opposite direction.
In my experiences, the direction of rotation for side cutters was determined by the geometry of the part, and how the cut is to begin. It's quite desirable to not climb mill, and a cut may or may not be through an entire part, so that tends to determine which direction a cutter will rotate. That's how I mount slitting saws as well.

H
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Harold_V
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Re: Horizontal Mill Spindle Direction?

Post by Harold_V » Sun Oct 29, 2017 1:58 am

wlw-19958 wrote:Although horizontal milling cutters can be mounted on the arbor either way, the direction is dependent on the threads on the arbor. You want the cutting forces to tighten the nut and not loosen it. That means, right-hand threaded arbors should be used for right-hand
cutting (counter-clockwise) and vise-versa for left-hand.
True to point, but large cutters are generally mounted with a driving key, so they can be operated in both directions, regardless of the hand of the arbor nut thread. There are times when one simply must run the opposite direction.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

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wlw-19958
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Re: Horizontal Mill Spindle Direction?

Post by wlw-19958 » Sun Oct 29, 2017 10:55 am

Hi There,
Harold_V wrote:
wlw-19958 wrote:Although horizontal milling cutters can be mounted on the arbor either way, the direction is dependent on the threads on the arbor. You want the cutting forces to tighten the nut and not loosen it. That means, right-hand threaded arbors should be used for right-hand
cutting (counter-clockwise) and vise-versa for left-hand.
True to point, but large cutters are generally mounted with a driving key, so they can be operated in both directions, regardless of the hand of the arbor nut thread. There are times when one simply must run the opposite direction.
Unless it is necessary for a cutter to run in a particular
direction, I think it is better to err on the side that will
tighten the nut, rather than loosen it. There is nothing
more frustrating that ruining a piece of work because the
nut loosened and the cutter started to wobble (even with
a driving key).

Good Luck!
-Blue Chips-
Webb

earlgo
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Re: Horizontal Mill Spindle Direction?

Post by earlgo » Sun Oct 29, 2017 11:24 am

I am certainly missing something here. This is my setup for a wide milling cutter turning CCW (facing the spindle) with a conventional cut. The cutter is keyed to the arbor and the nut is RH thread pulled up tight.
wide mill.JPG
wide milling cutter
cutting the key.JPG
cutting the boss with a narrow cutter
I am having difficulty figuring out how the nut is going to become loose. Please explain this to me.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.

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