Tube Cutter

Hi,

Hello,
I am in the process of building a CNC pipe cutting machine. I'm facing some issues that I would like to resolve with your assistance.
How can I set up a tandem motor with a different step rate from the main motor, specifically on axis A (rotary/angular), without it losing synchronization?
Additionally, there's an issue when the G-code includes negative angles - in such cases, the speed always decreases. I'll now share my test G-code and a portion of the .hall file where I made modifications to ensure that the tandem motor on axis A rotates at the same speed as the main motor.

Thanks

Attach the hal and ini file, some pictures of the machine, and please do not make us chase edited gcode, post the gcode as you are using it. Or you are running manually edited gcode?
I have made several tube cutters, currently waiting for parts for a 6 meter one that can do 320mm diameter, the build logs are here in the forum.
Having different step scales for the same axis is doable for sure, granted they do not have some funny step rates that can not be properly divided. Editing the ini file is the only thing required, and it does not require what you showed.
But you did not upload the whole ini file, just a part that explains nothing.

Hi,
Attached are the .ini and .hal files. This "modify" excerpt was done in the .hal file to have the same angular velocity on both motors of axis A. I'm also sending the unmodified .ngc file in the attachment. Is Axis the best launcher to use for this type of machine?
 

Is there any way, by making certain changes in the ".ini" file, that would allow me to have a tandem motor setup on axis A (rotary)? I'm still using the Axis configuration.

for 2.8 and above, In theory, it should not be any different to a gantry machine setup. Set negative Home offsets in the ini file and change the sign of the step scale if the rotation direction  on one is wrong. read the homing configuration docs.

So, am I supposed to set up axis A (tandem) in the same way I create a linear tandem axis in the .INI? If yes, how can I do it, considering axis A is rotational? If I follow this approach, do I still need to create a stepgen in the .hal file like I did initially, but in a different manner? Is there any possibility of doing this using pncconf? Would using the AXIS launcher be the best choice for this type of machines?

Does anyone have any suggestions?