Tell me about rotary axis

[Dave Johnson29]

Hi people,

I did a search here and visited Epilog and ULS' sites and no answer to my quandary.

Are rotary axis powered devices as 3rd active axis (A-Axis traditionally in the CNC world) or are they just a manual positioning device?

I read a post this morning regarding lasering a beer mug and it said, "the weight of the handle..." this got me to thinking it must just be a manual device.

[Pete Simmons]

Take a look at this thread

http://www.sawmillcreek.org/showthre...ry+tool&page=3

it will show my home made rotary tool which is basically the same as the factory model.

A stepper motor supplies the movement.

The beer mug handle problem is because friction it the only connection of the mug to the rotary and sometimes things like a mug will slip.

That is why I includes a pen mandrl on my rotary tool to enable precise vector cutting on pen bodies for inlay work.

[Richard Rumancik]

. . . Are rotary axis powered devices as 3rd active axis (A-Axis traditionally in the CNC world) or are they just a manual positioning device?

They are controlled by the computer. When using a rotary device you lose the y axis motion and substitute the rotary in its place. This allows the computer to rotate a cylindrical object so you can do multi-line engraving or large images that wrap around the item. When rastering with the rotary in place, the x-motion is back and forth as usual but the rotary increments rotationally for each pass of the carriage. The y axis will be effectively locked in one place coincident with the rotational axis of the spindle.

A manual device could be used for multiple lines of text such as on a pen but it would not allow you to wrap a continuous graphic. The other advantage of a rotary is that you are always in focus. If you laser a line of text on a cylinder without the rotary you will not be in focus at the extremes. You need to chose an "average" focal point. For small text/large cylinders the distortion might not be noticeable.

[Dave Johnson29]

When using a rotary device you lose the y axis motion and substitute the rotary in its place.

Hi Richard,

Thanks for that information it is exactly what I needed in order to understand how they work. I am amazed at the idea of using the Y-axis drive. Very cool and simple rather than adding the complexities of a 3rd live axis.

So now I just need to find a small 0.9 step/rev stepper.

[Dave Johnson29]

Take a look at this thread

http://www.sawmillcreek.org/showthre...ry+tool&page=3

it will show my home made rotary tool which is basically the same as the factory model.

Hi Pete,

That link shows Mike Hood's factory version (I think) but I cannot find any links to your home made one. I will do a search for rotary and your name, but thanks for the information.