Parametric thin wall test object

thingiverse

This is a thin wall test with both rounded and sharp corners. My slicer says it takes about 0.29m of filament, so it's a cheap test for adhesion, elephant-foot, speed, retraction, cornering, dimensions, thin-wall extrusion, and quality. You can set the wall thickness to be your nozzle's ideal extrusion width. These three stls have different wall thicknesses: | part | wall mm | |-----|-----| |thinwall_20_30_10_0p50.stl | 0.50 | |thinwall_20_30_10_0p60.stl | 0.60 | |thinwall_20_30_10_1p00.stl | 1.00 | I printed the pictured rough white part back in 2012 on a home-built [Wallace](https://reprap.org/wiki/Wallace) with my own version of a [Wildseyed MIG Welder Tip hot end](https://reprap.org/wiki/Wildseyed_Simple_Hot_End#Step_Three_-_The_MIG_Welder_Tip), and wanted to redo the test on my new printer, but didn't have the pattern. So I hacked up the green one based on https://github.com/Irev-Dev/Round-Anything : ``` // thinwall_20_30 -- thin wall test piece, copied from memory // Uses polyround from https://github.com/Irev-Dev/Round-Anything // https://www.thingiverse.com/thing:6216210 // Wall thickness thick = 0.5; // 0.01 // length x = 30; // width y = 20; // height z = 10; // corner factor -- try 0 to sharpen the corners c_scale = 1; //0.1 // corner add -- try 3 to add 3 to the radiuses of the corners c_offset = 0; //0.1 $fa = .01; // facet angle $fs = $preview ? 5 : 1; // facet size $fn= $preview ? 32 : 64; // facet number thinwall_rounded(); // x,y,radius radiiPoints=[ [0, 0, 0 * c_scale + c_offset ], [x, 0, 10 * c_scale + c_offset], [x, y, 10 * c_scale + c_offset], [0, y, 5 * c_scale + c_offset ] ]; use <Round-Anything-1.0.4/polyround.scad> // https://github.com/Irev-Dev/Round-Anything module thinwall_rounded(){ linear_extrude(z){ shell2d(-thick)polygon(polyRound(radiiPoints,30)); } } ``` If you use OpenSCAD, you can use the above code to customize the dimensions, but this code won't work in the Thingiverse customizer because it doesn't have the library available. The attached .scad file includes a slightly modified copy of RoundAnything so it works within the Thingiverse Customizer. in customizing I added a couple features. I added a couple terms to override the corner radii so you can scale the radii up or down, or add a constant. With settings X=40, Y=40, Z=50, C_scale=0, C_offset=5, it will make a 40mm calibration cube, with a 5mm radius on each corner, like:  With the "bottom" parameter, you can add an optional bottom. Or if bottom is set negative, it produces a bridging web at Z/2 (the wall need to be thicker to adequately anchor the web) The mixed-radius edges give the part a definite x-y-z orientation once it is off the plate: The X direction is from the sharp corner to a large radius, and Y is from the sharp corner to the smaller radius, which gives Z as up. So if you hold the part with the big radiuses to the right, and the sharp corner on the left and toward you, +X is right, +Y is away from you, and +Z is up. The part will have the X and Y dimensions, and radii larger than would be smoothly adjoin the walls will be constrained, so if you want a round tube of a certain diameter, set X=Y=diameter, and use c_offset =X/2 and c_scale=0 to set the radii larger than the radius of the circle. These simple vases are somewhat handy for supports. Take a look back to the 2008 thing #36 minimug: https://www.thingiverse.com/thing:36 You can recreate the classic Minimug.stl with: X=Y=26mm, Z=20mm, wall=2mm, C_scale=0, c_offset=13, bottom=2mm.