Big usability improvement to StepperSim!
For the (most) of you who don’t know what StepperSim is, it’s a series of spreadsheets I made that allow 3D printer builders to predict stepper drivetrain performance for some common stepper drivers. See:
If you follow the instructions and input your printer’s hardware specs, it will tell you whether your prints will have ripples caused by skipped microsteps (as is common with 8825s) and approximately how fast you can safely run the drivetrain.
The update:
I found a way to estimate a stepper motor’s back-emf constant in a paper on motor modeling. That means the stepper simulator inputs now only require standard motor datasheet specs – you don’t need to physically measure anything to fully use the simulator. (Real measurements will improve accuracy though.)
So, if you’re not a crazy person like me who likes measuring motor constants, you can now use the helpful back-emf “suggested value” to get pretty good results for the high-speed motor behavior. Previously, if you didn’t know the motor’s back-emf constant, the simulator was only useful at low motor speeds.
Yes, you still need the basic motor specs – rated current, holding torque, resistance, inductance. I can’t help you with an unlabeled motor out of a junk pile. But you probably shouldn’t be building precision robotics with unknown junk motors anyway 
Everyone uses unknown junk motors. The highest quality is typically kysan or wantai. Forget about Japanese brand steppers or anything actually made for industrial use.
@Stephanie_A agreed that those are pretty low-quality motors, but we do have enough specs for them to do some useful engineering. Ideally I’d like to see detent torque and a torque/RPM curve for every motor, but beggars can’t be choosers.
I like the idea behind this. I think the hobby could use some more of this kind of engineering. It’s not required to get something running but to get optimal performance this could be useful.
I’d love to create test setups and gather data, but the cost of the setup is above my price range, which is zero.
Aside from us hobbyists… I see a little bit of stepper ripple in a lot of nice OEM printers, like Ultimakers and Airwolfs. People running 24v PSUs and very low print speeds are likely to run into it. Very preventable though, if you use the simulator to select parts and pick the decay mode.
One of the reasons why I like the polulu style carrier boards.
Yes, but most of the Pololu style carrier boards come configured sub-optimally… So you can solder on a StepStick or solder on a mainboard, doesn’t strike me as much difference.
Hello Ryan… and how is your core XYZ ? I am wanting to mount a well here in Brazil
@Rafael_Sekiguchi sorry to say it is in a closet waiting on its turn to get a new controller board. Too many other projects to work on.
I had the same thought in setting up an equal his. I know that in his comments said do not want to work with a MEGA , but not for drive tests?
My CoreXYZ build currently has a Mightyboard in it with a Sailfish test build that allows it to run three motors with the correct kinematics. But the drive forces are unbalanced without the fourth motor so it can’t print that way. I need to use a controller that can run 4 motors like MachineKit.
