Hello,
I'm building a CNC router with Mach3, using a parallel port for control. For the Y-axis, I have two motors:

One method is to connect both motors' Pulse and Direction pins to the same parallel port pins (common signal method).
The other method is to connect the second motor's Pulse and Direction pins to the A-axis outputs and configure Mach3 to slave the A-axis to the Y-axis.
Which method do you recommend for better synchronization and reliability? Are there any risks or disadvantages to using the common signal method to control both motors?

Thanks in advance for your insights!

Hi,

Welcome to the forum.

Common signal is not recommended.
Mach is designed to allow homing and squaring of the gantry using slaved axis.

Hope this helps.

Tweakie.

Hi,

Welcome to the forum.

Common signal is not recommended.
Mach is designed to allow homing and squaring of the gantry using slaved axis.

Hope this helps.

Tweakie.

Thank you.
By the way,

Is it possible to provide at least four corner Z-height values to the MACH Software system in order to compensate for height differences?

I mean:

- The height information of the four(or more) corners of the table is provided to the MACH3 system in advance.
- During cutting, MACH calculates the required Z height from the G-code and corrects and applies the Z height accordingly.

I suppose it would be possible by probing the surface at different points and then creating a height map which could be used to provide Z axis compensation but I have never done it so have no experience of this.

I just simply affix a sacrificial spoil board then surface that to get a flat table.

Tweakie.

For your CNC router project, there are two methods to control the two motors on the Y-axis: one is to connect the pulse and direction pins of both motors to the same parallel port pins (shared signal method), and the other is to connect the pulse and direction pins of the second motor to the A-axis output and set A-axis as a slave to the Y-axis in Mach3. The shared signal method is simple and easy to implement but may have minor synchronization issues; whereas configuring the second motor as a slave may achieve better synchronization but requires more setup and debugging work. Choose between them based on your needs, and make sure to conduct thorough testing and debugging to ensure the system operates smoothly.