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.
All the DIY CNC machines I’ve seen use larger stepper motors. The commercial CNC machines I’ve seen can cost $10,000 to hundreds of thousands.
It seems like the argument is that at the lower price bracket, stepper motors offer higher performance than what a equivalently priced servo+encoder+controller combo can perform.
I felt like what I was reading in this thread wasn’t matching up with that I see out in industry… concerns about ‘price’ didn’t come up until your post.
Diamond turning machines are inherently low torque, low speed, AND nanoscale operations which uses servos for driving its respective axis. See precitech -youtube and in stark comparison Roeder’s 5axis optical mold machining. Wire EDM’s were all driven by servo motors until linear motors became popular. Even those famous JingDiao test samples are made on machines driven by servos.
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Roeder’s 5axis optical mold machining
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That’s actually exactly my point, steppers are objectively inferior to servos when it comes to dynamic positioning (which is what 3D printing is), but servos are too expensive compared to performance gains for hobbyists.
Which makes them superior, which is why they are used. Cost can’t be ignored any more than the torque or speed, speccing parts that are considerably more expensive that achieve equivalent results is bad engineering unless you have a very specific application that requires it.
If it was ‘objectively inferior’ we wouldn’t use them. You build to your requirements, not by playing top trumps with competing technologies while ignoring the cost.
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.
