View Full Version : What Is The 'Swing' On A Mill?

02-04-2010, 10:34 PM
Sounds like a simple question, but I have no idea what this dimension defines. Anybody?

02-04-2010, 10:37 PM
A lathe has a "swing". Mills are described by table length and width.

02-04-2010, 10:57 PM
On a drill press, the swing is the largest thing where you can reach the center of the piece.

A drill where the spindle is 8 inches from the pillar will allow you to drill a hole anywhere on a 16 inch disk, so it's often referred to as a 16 inch drill press. Some call it an 8 inch, so you have to look at the specs. :)

It would seem that a mill may have the same designation. A mill with the head mounted on a ram will have a larger work envelope than a similar mill with a fixed head.


02-04-2010, 10:58 PM
If you look at mills in the catalogs, you'll see a spec for 'swing'.

For instance, a Grizzly G0619 has a 6" x 21" table, a headstock travel of 14-7/8", and max spindle to table distance of 14-3/4". The 'swing' is 18". I've seen this spec in catalogs of other brands, too.

Dan, I was typing this when you posted your response. You may be correct, but I wonder how the table travel would affect this. By your definition, I would guess that the distance between the column and the bit would be 9" in this case.

doctor demo
02-04-2010, 11:03 PM
There are pictures floating around this forum that would show that Your question relevant.
If ya put a chuck on the spindle of a mill it then has ''swing'' or a turning capacity similar to a lathe.


02-04-2010, 11:31 PM
The spec on that grizzly mill says spindle column is 8 inches... so that does not track exactly. But close enough.


02-04-2010, 11:38 PM
It Don't Mean a Thing If It Ain't Got That Swing (http://www.youtube.com/watch?v=o8qGa4Yh2qs&feature=related) :D

02-04-2010, 11:44 PM
Looking at it from a drill press point of view if you move the head as far out as the travel will allow and measure from the center of the spindle to the part of the column that sticks out the most then that would be the swing. You may not be able to do any machining at that point because the table and head are at their extreme but that is the swing of things.

02-04-2010, 11:50 PM
Sounds like a simple question, but I have no idea what this dimension defines. Anybody?

Without checking further, my guess is the radius from the swing centre of the spindle centre to the centre of of the swinging head on a BP type mill or from the centre of the milling head spindle to the centre of the column in a round column mill.

02-05-2010, 01:04 AM
I would think it would be the same as a drill press. The max distance from the center of the quill and the column
In other words it would be the max you could swing on a RT

02-05-2010, 09:45 AM
I have some old catalogs that describe drill presses by "Will drill to the center of circle __ diameter." This is analogous to the swing of a lathe, so I would assume it describes a mill the same way. The biggest circle that can be centered under the tool; if the machine can reach the center then it can reach every other part of the work. It is a reasonable way of describing the biggest piece of work that you can fit in the machine.

On a drill press this measurement is fixed: the distance from the center of the chuck to the column is the radius of your circle. Something similar is certainly possible with the mill, a trammel head would give more reach, so the measurement retains it's usefulness. Or possibly its sales-usefullness by generating the largest possible number ;-)