Combined width & horizontal size compensation calibration part

thingiverse

A common problem with using the well-known calibration cube of arbitrary size to calibrate x/y scaling is it omits any increase in width due to the FDM extrusion process. This results in those small ripples at the edge of your part. Other calibration parts suggest reducing your flow rate to adjust wall thickness, but this is a very bad idea. To exactly calibrate for A) x and y scaling and B) horizontal size compensation or exact wall thickness, you can use Print Part1.stl (the bigger part) and measure inner dimensions (ID) and outer dimensions (OD) on both the x and y axis. Then for each axis separately: Your new scaling factor is Old scaling factor * ( 100 mm / ( ID + OD ) ). The walls are printed too thick by ( 20 mm + ID - OD ) / 2. To reduce wall thickness, use appropriate tools like the "horizontal size compensation" Simplify3D offers in the "Others" tab. The value to put there is ( OD - ID - 20 mm ) / 4. After putting in all compensations, print both Part1.stl and Part2.stl. They should fit each other quite nicely if you push a bit but not too hard. If they don't fit yet, further increase wall thickness compensation a bit.