Control board question for CNC lathe with servo spindle

Hi everybody, I'm new to this forum and to linuxCNC, I want to convert a small Hobbymat MD65 lathe to cnc, to make small aluminum hardware parts and some custom furniture screws for woodworking. I have two nema 23 steppers and drivers, as well as a 400w yaskawa servo and its SGDH-04AE drive. I'd like to do threading with the machine, hence the servo spindle. I'd like not to spend 200$ on a mesa card, is there any way I can do CSS threading with G33, using either the step/dir interface, or the speed control (with encoder feed back), directly on a parallel port breakout board or any other cheap board? thank you very much 

Yes, all that is possible with a parallel port interface.
The main limitation will be encoder resolution, the possible
encoder counts per turn*spindle RPM will be limited by
the base thread rate. You would probably be OK up to
100 PPR or so.

Thank you for your answer, do you have a recommendation for a suitable board?

yes it does, it can be driven by speed control, torque control, or step/dir input, but will step/dir control work with G33?

PaulQUE wrote:

Thank you for your answer, do you have a recommendation for a suitable board?
 

Not that familiar with parallel port breakouts but make sure you chose one that has inputs
suitable for your spindle encoder (most will have 5V signals) The common Chinese
"5 Axis Mach3 BOB" has 12V inputs

PaulQUE wrote:

yes it does, it can be driven by speed control, torque control, or step/dir input, but will step/dir control work with G33?
 

If you have a spindle encoder,  G33 will work with any spindle  (even with no controls at all)
G33 can work with a 2 wire encoder (A and Z)  or even a single  wire (A+Z) 1 PPR encoder
since it does not need to reverse.

G33.1 requires a spindle that can reverse and a full 3 wire ( A, B,Z )  encoder

Theoretically G33 could work with a step/dir position controlled spindle,
without an encoder but this would require some changes in the stepgen
component to:

1. Generate a simulated index once per turn
2. Handle position feedback reset at index and index-enable
 

A 7I96 is $119 plus shipping.

A cheap / generic breakout board may cause multiple issues. They are cheap for a reason.

A good quality parallel port breakout board may not save you that much $$$ compared to a 7I96. Parallel port breakout board will have less performance - not an issue in a slow machine usually but depending on latency of PC hardware can still be an issue.

I have built multiple machines both with and without a Mesa board. I would not build another machine without a Mesa board / hardware pulse generator.

thanks for the information, I would not have thought of looking at the required input voltage otherwise. my yaskawa drive outputs an RS422 signal for the three wire encoder. The only breakout board I could find with 5v input signal is the C10, which, on the other side, does not feature 0-10V speed control, which I would like to use to control the servo spindle.