I am using my rotary as an X axis control for long flat work and while I have tuned the heck out of it, I am still having some alignment issues. This makes me wonder, does Lightburn do any “math” to change the geometry of pieces at the edges of a rotary cut? like does it think "the curve should be X so I need to change the geometry by Y so that the “edges” of the engraving account for the curvature of the part?
Obviously for me I don’t want that… but I got to wonder if that is what I am seeing trying to get the rotary feature lined up.
you have to give it the diameter of your object any time you engrave anything… its one of the primary settings on the rotary run window… Otherwise it doesn’t know how many motor steps = a specific amount of distance on the object.
In my case because I am using it as a flat X I only have to set it once but its there to be set for every object if this was a traditional rotary.
How large split size are you using/ what lens? Belt or ball screw X table?
I’ve got my X table under construction right now making it an XY table so I can’t test, but seems like low cost ball nut drives and most belt drives can have an accuracy less then desirable, maybe upwards of 0.1mm. My rotary rotates CW to starting point, then CCW to burn so I assume that is taking up a repeatable amount of freeplay. With my Z drive the macros always run the position past the starting point and then screw “Up” to remove any play when moving to a new starting point, As I’m sure the screw is not of very high precision. Maybe need to work something like that into your strategy for dialing in.
its a 400mm ball screw… No detectable backlash and on pretty ok linear rails… I don’t love the 2040 extrusion that is the base, but thats’ about the only thing that gives me pause for the forces and loads involved…
(I have a bit of experience building CNC machines… I have no doubt this is accurate within .03mm (or roughly a thou if you like freedom units).
