Query regarding upgrading a Sieg C6 lathe to CNC

[-= Keith =-]

Hello.

im wishing to upgrade my manual C6 lathe to CNC.
the lathe i have is the C6 basic, which DOESNT have variable speed chuck - only the six predefined by pulleys.

C6 basic: http://www.axminster.co.uk/images/pr...m/210171_l.jpg
C6 Variable: http://www.axminster.co.uk/images/pr...m/210172_l.jpg


for some reason i was under the impression that in order to turn into CNC, you need a variable speed type pesumably with an output so the software (mach3) knows what angle the chuck is in regards to the lead screw

in manual mode the leadscrew is connected to the motor mechanically.
if you do hi torque operations such as thread cutting and the chuck slows down by say a revolution per minute, then the lead screw slows down, giving an even thread.

If there is no direct link between the mechanical side (motor set at 250rpm) and the software other than telling the software its rorating at 250rpm, and you apply a load, how does the software know to slow down the cutting?, other wise you will be left with an uneven thread.

i only ask this because ive seen this from Syil
it is based on the basic lathe.
http://www.amadeal.co.uk/acatalog/Syil%20C6.jpg

pleae note i have a cncmill, and so was going to convert as i already have the motor driver box for that

thanks
KEith

[doorknob]

People who are doing operations such as threading on a CNC lathe conversion typically use an optical sensor and an interruptor connected to the spindle (for example, a metal tab on the back side of the spindle housing that rotates with the spindle) to generate an index pulse signal.

This is a typical interface board used to generate the signal for such a function:

http://www.cnc4pc.com/Tech_Docs/C3-I...ual_Rel5_1.pdf

[-= Keith =-]

thankyou.