I took sudhir's excellent customizable solder holder and added a fillet to the area where the clip meets the wall using a fillet library (file included). I felt that this intersection was a little weak and might one day break. Unfortunately, fillet libraries a slow in OpenSCAD, so you might need to be patient. Open the file and set the parameters at the top for your spool. A faster way to check what the final product will look like is to use sudhir's original model and then just copy the parameter values into this scad file.