This is a slight improvement on
http://www.thingiverse.com/thing:533814
where I have cut off the left lower corner at an angle so you figure out the part orientation after removing from the build plate.
You MUST either measure your errors with the print still on the buildplate OR print with a raft and remove with the print still adhered to the raft (my preferred method). Using this I can get alignment within 50 um on repeated prints.
Advice: 1) print at high resolution and scale up the z to 2mm to improve the accuracy of your offset measurements. 2) When you get close, use a feeler gauge instead of calipers. 3) if you are using a Raise3d slicer, print with the wipewall -> since the colors are supposed to print right on top of each other it helps get a quick idea of offset.
Dual_Extruder_Calibration_Target_A_v1-1.STL | 111.8KB | |
Dual_Extruder_Calibration__Target_B_v2.STL | 77.8KB |