Threw this together in OpenSCAD, to use with Teaching Tech's flow calibration page here.
Normally you'd use a simple cube model, but on a 45° printer a cube's walls aren't perpendicular to the nozzle. This model, printed with zero infill and zero top layers, will give you three walls (top, and both sides) to measure for the flow calibration.
Follow the instructions for Teaching Tech's flow calibration tool, substituting this model for the cube
Huge thanks to Teaching Tech for the calibration page, and Stewart of GridSpace for my favorite CR-30 compatible slicer (Kiri:Moto)
The author marked this model as their own original creation.