RE: [CAD_CAM_EDM_DRO] Re: Sherline Spindle Pulse disk for threading

Hi Fred,

>
> We use a 500 line quadrature encoder with index pulse. This permits
> the Sherline lathe to stall under a heavy cut, and yet by turning the
> spindle, the 2000 counts per revolution keeps the threading tool
> synchronized to the spindle. It also permits the spindle to lug down
> to whatever speed it can maintain under the given cutting
> conditios and
> still maintainthe tool position. Simply forgetting to oil the thread
> between passes can sometimes cause enough load to stall or severely
> slow the spindle.
>
> Here is a link to some steel threads that were cut on a Sherline:
>
> http://www.imsrv.com/sherlinemachines/#lathe
>
> This describes how the threading process is done:
>
> http://www.imsrv.com/deskcnc/lathe/desktopcncthreading.pdf
>
> Fred Smith - IMService
> http://www.cadcamcadcam.com/hobby

Nice stuff!!!!

As the EMC people are also fond of saying, a tightly coupled system
with a multi-line encoder makes a world of difference for creating
threads with varying spindle speeds.

I'll be the first to agree. Of course the price of just the encoder kit
for the Sherline at $169 is $19 higher than the entire budget for the
Electronic Lead Screw. <wink>

John Dammeyer