Why are 3D printers still stuck on stepper motors? Why haven’t we transitioned to servo motors with encoder feedback for positioning?
Is it just too cost prohibitive for the consumer-level? We would be able to print a lot faster and more accurately if we had position feedback on the axes. Instead we just rely blindly on the stepper not skipping any steps when we tell it to move, hoping for the best.
I don’t think the sentence you have is entirely accurate.
High cost servo systems (motor, encoder, and driver) are superior to high cost strippers for dynamic positioning. Even that can be tenuous for low torque low speed applications, or nanoscale applications, etc… Certainly for 3 axis table/gantry CNC systems (router, laser, 3d print) for commercial/industrial grade applications servos are superior.
If you’re aiming for a hobbyist price point steppers have better dynamic positioning performance than servos. You can build a $300-$1000 3d printer with servos, but especially at the low end, it’s not going to be good.
But that just highlights the statement/question in my OP, it’s just cost prohibitive to use servos as a hobbyist. You will as a hobbyist get a better system with (proper) servos, but not for a reasonable price point.
If you are buying industrial grade 1000+ dollar servos you are no longer “hobbyist” in the price range that hobby level 3D printers exist steppers are more precise than servos.
in the price range that hobby level 3D printers exist steppers are more precise than servos.
Yes that’s exactly what I’m saying…it’s the cost that’s in the way of the switch, not that steppers are the best solution. They’re only the best solution within the price constraints we have as hobbyists.
You will not get a better system when using servos no matter the price point at the moment. People have tried and failed just because the software support isn’t there yet for 3d printing.
The biggest issue I’m aware of is matching the timing between the extruder stepper and the servos that do the XY motion.
Which isn’t apparent at lower speeds but at higher speeds you can notice they’re no longer in sync which leads to all sorts of issues and artifacts.
I’m currently waiting on some 3 phase steppers and drivers to test to hopefully get something with less speed deviation than a normal 2 phase stepper and more reverse torque but don’t cost too much and are still easily driven by connecting a driver to your boards step/dir output.
