Aluminatus Print Bed Retainer

I have been using the typical aftermarket bed holders, as found on Thingiverse, for years, but finally gave up on them; they loosen up and the bed starts to move around.

The replacements that I designed are dead simple parts that assume that you have drilled and tapped 4 1/4-20 holes in the aluminum spider. Just use 1/4-20 hex head bolts to attach the 3D printed retainers and you are good to go. They were designed using OpenSCAD. I printed them in PETG, on its side so that no support is required. Sorry that the object view is so bad: no way to alter it on Thingiverse that I can find.

They are not adjustable when on the printer, so you will probably have to adjust the section in the source code called "cut out the top" to adjust the corner of the build plate with respect to the corner of the aluminum spider. You can also adjust the screw hole at the bottom of the source code if you are using smaller mounting hardware.

I inserted paper shims between the bed and the bolt h