How to double increase torque with silent stepper driver LV8729 #configuration #bluepill


Hi everyone, i have a question and need your support, please help. Im building my FORK mount ,it will carry a 20kg binoscope and maybe bigger equipment in future. I already have two 57x57 1.5A step motor that make me concern about the torque because it's all small motor . Besides, i have two LV8729 that saticify me with its super silent operation.
So, i have an ideal to double increase torque power for two axis. This will be two 57x57 step motor with two LV8729 driver for axis 1 and the same configuration for axis 2.
My questions is :
1. For examples bellow circuit, can i use both two LV8729 with two motor for 1 axis at same time ?
2. For big ,heavy system, if i have good mechanical design, can i use small and low torque stepper motor ?
Thank you.

John Petterson

A couple of thoughts.

I would worry that if one of the drivers missed a step pulse and they got out of sync the two motors could end up fighting one another.  Some 3d printer boards (the FYSETC S6 is one) have multiple outputs for the Z axis, and they do it by putting the two motors in series connected to a single driver.  I think that would be a safer design because then you know they are being driven the same.  You might have to do something with the voltage to that driver to make certain the motors were being driven with enough voltage.

Having said that - as long as your mount is reasonable in terns of friction and the scope is balanced in altitude, there should not be enough load to require multiple motors.  We have many mounts with payloads that high and higher that are running with NEMA 17 motors.

Robert Benward

I know of CNCs that have two motors and screws to drive one axis of the table.  As John mentioned I would be concerned about synchronization.  Sounds complicated mechanically as well.  I would go to a bigger motor, and if needed, and external driver.