Hi Christoph,
Thank you for providing such detailed information.
Are you using the motor in series mode? The graph appears to show that the motor may stop running around 1400 rpm in series mode.
If you have not done so, may I suggest you contact the manufacturer to understand what the difference between the series and parallel graphs.
On the DRV8711, you can try using full step with the step input decreased by half and the current increased by 1.4x
Thank you for providing such detailed information.
Are you using the motor in series mode? The graph appears to show that the motor may stop running around 1400 rpm in series mode.
If you have not done so, may I suggest you contact the manufacturer to understand what the difference between the series and parallel graphs.
On the DRV8711, you can try using full step with the step input decreased by half and the current increased by 1.4x