Customizable Mesh Calibration Pattern

This is a customizable test pattern for testing and calibrating mesh bed leveling.

There are quite a few test patterns out there already, but I found most to be too complex and many are just static STL files that aren't customizable. So, I created this.

Either download [OpenSCAD](http://www.openscad.org/) and use it to open the SCAD file or customize it directly here on Thingiverse:

Mesh Settings
- Test Circle Radius: this is the size of the test circles
- Mesh Points: Select the mesh size. If you use a different size you can just enter it directly in the OpenSCAD editor

Printer Settings
- Layer Height: the height of the test circles, this should match your printing layer height
- Bed Width & Length: this should be set to the bed width and length you have configured in your slicer
- X & Y Inset: this is how much distance there is between the edge of the bed and the *center* of the test patterns. This should be at least twice the value of `Test Circle Radius`