The question is..

[OCR]

Can you. . .

Turn a CUBE on a LATHE?!

.

 

[jedishrfu]

I guess this is a late April Fools Day joke.

 

[Baluncore]

Can you. . .
Turn a CUBE on a LATHE?!

Yes.
But it will require mounting six times, once for each face.

1. You can hold the cube in a 4 jaw chuck, then face the end with a tool in the cross slide. Since the centre is not important, depending on what shape you start with, you might hold the work in a 3 jaw chuck.

2. You could clamp the cube to the cross slide, then face it with a cutter held in the chuck. But that would be more difficult to set up for accurate angled corners.

The example shown in the video shows multiple passes of a fly cutter. That suggests it was clamped to the cross slide, but more probably faced in a small milling machine.

 

[DaveC426913]

Yes.
But...

Not sure if Baluncore is deadpan riffing on joke, or

What I saw was: A lathe. With a cube on it. Being turned.

 

[Baluncore]

What I saw was: A lathe. With a cube on it. Being turned.

Repeatably, again and again.
The example cube that turned up on the lathe was not turned up in the lathe.

How could I miss the opportunity to deliver deadpan, a couple of other obtuse ways it could be done, but in, not on the lathe. Can a lathe have obtuse ways, or is it only me ?

 

[DaveC426913]

How could I miss the opportunity to deliver deadpan,

Thought so.

 

[wirenut]

Yes, it is possible. See "machining a cube on a lathe" by machiningmomentsbrad on youtube.

 

[DaveC426913]

Yes, it is possible. See "machining a cube on a lathe" by machiningmomentsbrad on youtube.

Yes, we know.

 

[sophiecentaur]

It’s not as convenient to produce a ball on a vertical milling machine.

 

[Baluncore]

It’s not as convenient to produce a ball on a vertical milling machine.

But it is very easy to turn a ball on the bed of a vertical milling machine.

Yes, it is possible. See "machining a cube on a lathe" by machiningmomentsbrad on youtube.

A ball or a cube can be produced pretty much anywhere a magician turns up to remove the cover.

 

[DaveC426913]

Machining a ball on a milling machine is functionally identical to machining a cube on a milling machine, except the number of remountings required is somewhat larger.

 

[jedishrfu]

Here's a video on making a jig that can move the cutting tool in a circular manner.

 

[Baluncore]

Machining a ball on a milling machine is functionally identical to machining a cube on a milling machine, except the number of remountings required is somewhat larger.

A tow ball can be made in one setting.
At most, only one remount is needed for a full sphere.

Spoiler

Mount the workpiece in an indexed head, with axis at a slope to the bed, or head tilted.

A single point cutter, offset by slightly less than the ball radius is mounted in the spindle to cut a circle on the ball surface.

While spindle turns cutter, slowly rotate the index head until you have a sphere.

 

[Baluncore]

Pictures help explain the geometry of generating a sphere in a milling machine.
https://www.ctemag.com/news/articles/generating-spherical-surfaces

In actual practice, you can’t cut a full sphere in one setup. You still have to hold the part and rotate it somehow. To produce a full sphere, you must use two separate holding setups.

 

[sophiecentaur]

Some interesting (and typically PF) responses here. I hope you all enjoyed that bit of nonsense.

It's largely a matter for definition, imo. If you put a morse 3 taper lathe chuck into the spindle of my toy vertical milling machine (and lay it on its side?), you've got yourself a lathe, afair. It could be argued that the workpiece rotates in a lathe and the cutters rotate in a mill - hence my use of the word "convenient".