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craigrobbo
27-08-2012, 07:47 PM
Hey guys.

My lathe has helped me out lots in the past and has more than enough power and size for what I use it for.

I decided I want to CNC it, Could anyone point me in the right direction please?

The ball screw on the Axis is fairly self explanatory, however I am struggling on how to control the motor (especially for threading) and also the tail stock for center drilling and other operations.

All advice is appreciated!

i2i
27-08-2012, 08:06 PM
i know of someone close to you selling a starturn 4 on Mach3

irving2008
27-08-2012, 09:15 PM
Hey guys.

My lathe has helped me out lots in the past and has more than enough power and size for what I use it for.

I decided I want to CNC it, Could anyone point me in the right direction please?

The ball screw on the Axis is fairly self explanatory, however I am struggling on how to control the motor (especially for threading) and also the tail stock for center drilling and other operations.

All advice is appreciated!

Here's a blog on the subject... Setup and CNC conversion of a Prazi MD65 or SD300 Lathe made in east germany 1988 (http://danielbauen.com/make/index.php/cool-tools/prazi-md65-sd300-lathe/)

Generally the CNC applies to the leadscrew, cross-slide and maybe to spindle speed (nice to have but secondary to axis control). For threading you need an encoder on the spindle so that the control software knows how many revolutions have occured. Needs a fairly high resolution encoder though the software can interpolate by time. The same data can be used for spindle speed control feedback.

You wouldnt CNC the tailstock as a rule (although it has been done). Centre drilling a part as a prep to CNC'ing it is generally a manual operation, and turning between centres for CNC is unusual (though again, seen it done). For actual drilling you would normally mount the drill in a collet on a tool changer, either a rotary one or a gang one on the cross-slide. Here's an example: http://www.youtube.com/watch?NR=1&v=9wbatJUciDY

craigrobbo
29-08-2012, 10:36 PM
Thanks for that, But its the money aspect, It would have to be incredibly cheap.