Increasing slew rate #wemos


I am running my CNCV3+Wemos D1 controller using LV8729 boards (1/64 microstepping) and 12V 5A supply. I am only able to get 2.49deg/sec max slew rate which is very slow. I would prefer something in the order of 4deg/s. I had set the Slew Rate Desired in the calculator as 4deg/s but its not reflecting in the performance. Please could someone let me know how to increase this?

Mircea Radutiu

What mount model have you got, what current are the steppers rated for and what current have you set the drivers for?
I have used LV8729 for 0.9A 0.9deg. steppers on an EQ5 mount with ~7kg/15lbs load and had set the Vref on the drivers for 0.6A, on a MaxESP3 board. Using voltages from 12V up to 24V I could not get them to behave OKish beyond 3.6 degrees/s, and even then, the noise they were making was like of something dying. 2.4 degrees/s seemed to be the sweet spot for these drivers. The microstepping used was 32. I had set 8usteps for the slew speed, but I do not know if it works with the LV drivers. If it did, well, I for one would stop at 2.4degrees/s. But then again, it also depends on the mount load capabilities and the load size.


I have a SW HEQ5-PRO.
Nema14HS13 Steppers rated for 5.4V 0.8A.
I have set LV8729 at 0.4A.
Typical highest payload does not exceed 8kg.
I have not set any micro steps for slew speed.

Khalid Baheyeldin

First thing to do is very easy, and no hardware required:


This should give you a 60% boost.

The step after that is more complicated: use TMC2130 or TMC5160, and rewire for SPI support.

Try the first point and see how fast it gets you.


Thanks Khalid,
I added the line of code and yes, I have achieved a faster slew rate. Thank You very much.
I have made yet another video on the faster slewing, its here.


The link in the previous email will not work because the video was modified and reuploaded. Its here.