Parameterized Angle Bracket

thingiverse

Brackets for joining wood or extrusions at various angles. A variety of sizes and angles are provided. The FreeCAD v0.19 file is included and the parameters are set from the embedded spreadsheet. Changing a number automatically updates the shape. Use large washers to spread the force onto the plastic for maximum strength. Use a dense and isotropic infill, e.g. 50% cubic. I printed using ABS / ASA with 0.5mm nozzle and 0.3mm layers. The ABS needs good bed levelling and a wide 10mm brim to hold it to the bed during thermal warping. Very shallow angles (>135deg) may need supports. Finite-Element-Analysis -------------------------------- The FreeCAD file works well as a test case for the [FreeCAD v0.19 FEM_Module](https://wiki.freecadweb.org/FEM_Module). To prepare the analysis: * Make the screw holes a bit bigger to help the meshing, e.g. 5mm radius * Start the FEM module and click the "A" button to add an Analysis * Select the last LinearPattern element of the Part * Select Mesh => FEM mesh from shape by GMsh and hit "Apply" * Add a material with the yellow ball button and choose "ABS-Generic" * Scroll down to the bottom of the materials tab and select the "solid" radio, then click "Add" and click on the bracket in the 3D view. * Click Apply at the top of the material tab. * Add the boundary conditions by selecting the Analysis node then Model=>Mechanical Constraints=>Fixed Constraint on the vertical surface. Then add a force boundary condition to the other mounting surface. * Double click the SolverCxxTools node, "Write .inp file" and "Run CalculiX". * Once the results are converged, examine the maximum von Mises stress to see if it is less than the yield strength for your plastic, e.g. ~20MPa for ABS.