Set Linear/Angular/Curve accuracy as 0.5 mm/deg (the 3 values)
Load the STEP file
Select Tools-Run Script and runCurve Filter Average Normals
Select the object you just loaded (you may have to select it twice)
Leave the filter size to 10 (default) and select OK, you can increase this to make it smoother.
You should see the result attached.
It looks like you used SolidWorks to generate the STEP file. Have you considered using theRoboDK plugin for SolidWorks? Importing smooth curves will work without having to follow these steps.
Nothing happens after step 4 there. Even if I click on the object on step 5, nothing pops up. I just tried uninstalling RoboDK completely and installing it again. No luck either. I tried opening your file to attempt it, same result.
Yes, I actually attempted this with the plug-in first. The issue however with the plug-in is that the normals are all in one direction. I didn't see any options in the plug-in that affected that. Is there a way to have the plug-in import the curve normals correctly?