I notice that in "configuration_adv.h" for the BIGTREETECH-SKR-mini-E3, which uses TMC2209 drivers, the similar section has:
#define HOLD_MULTIPLIER 0.5 // Scales down the holding current from run current
#define INTERPOLATE true // Interpolate X/Y/Z_MICROSTEPS to 256
While the following doesn't conclusively prove changing the motor would work, I think the answer is yes! And I achieved the desired result via a different method, so I consider the problem solved.
Instead of changing the motor, I designed a 1:4 step-up planetary gearbox to put on top of the extruder motor, yielding a 10:1 net reduction instead of the ...
In general I would use https://github.com/rcarlyle/StepperSim which takes into account more parameters.
You can play with voltage and current to see which combination gives you the best results for your motor.
Or you can change to a TMC driver with higher voltage (35-50 V) to keep torque at much higher speeds and push the current motor more.
Since the torque ...
Stepper motors "want" to keep their position as they are told to by the firmware, therefore they do whatever it's needed (accelerate and brake) to follow the orders they received.
The question is: is the firmware telling them to move/accelerate/brake faster/harder than they can? if yes, they won't keep up (because of inertia and much more) so you'...
I was considering buying a Fl3xdrive but had this exact fear, that the speed (rotation) required for retractions was too much.
I stumbled upon this post while looking for a project for a step-up gearbox. I found a Nema 17 Gearbox "Pulleybox" Mod for Extruder on Thingiverse, should be enough to do what you did with your design, I guess.
During normal extrusion backlash has no effect.
During retraction you can perfectly compensate by increasing retraction length slightly.
Backlash cannot be taken into account for pressure advance, but unless it's a lot, it should not cause issues: pressure compensation is a second order effect and does not need to be tuned super accurately to produce results....
After several email exchanges with the customer support, I was not able to find an answer. It was stated that it may have been my assembly and/or extruder mount, but I'm strongly against that after so many times reassembling.
Gear backlash ended up becoming permanent.
I ended up switching over to something else with a more self-sufficient design and less ...