Build plate levelling shim (Based on the Saddle equation)

This shim uses the Saddle Equation but will only help reduce bed distortion if your bed distortion follows a classical "Saddle shape" otherwise it may make it worse. The shim if printed thin enough it will sit firmly in between a magnetic build plate and the magnetic bed. Note it has to sit upside down to help cancel out the bed deviations. Depending on your choice of parameters It may also be rotationally sensitive about the Z-axis and you will need to experiment to find out the best orientation NB, the STL file provided is for my printer - you will have to interact with the OpenSCAD file to generate the STL to suit your own printer bed distortion. Use Fluid to measure the range of printer flatness and assess the extent of Positive and negative deviation needed. Change the parameters in the Open Scad file till it covers the range and shape of your Fluid levelling data The best improvement I have been able to get for a bed with a about a 1mm range of deviation is about a 30% improvement. I will eventually post another SCAD file that uses Fluid levelling data from your printer to make a custom make shim - Using this I have got my deviation