Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4516893.

Photo is of first iteration which the clip was not quite strong enough on top and required a bit of glue, it was also a bit to close to the frame.

The STL model is version 2 (I haven't printed this version yet) that should fix these issues.

This is basically the original i3 mount with the Huxley Y carriage idler mount joined in the front. Does the job.