How about if you made a “Gallery” category here in your forums – and place it high up in the Categories list. That could also have a plus side to it, in that you might see a little additional traffic to your site? Plus, it seems a kind of logical place to look for such a gallery. Plus it would add a generally smiley side to a forum which largely consists of problems. That said, I am very impressed by your quick, knowledgeable, caring responses to all help-seekers.
Thingiverse does have a lot of images, but there’s no one URL I can just bookmark to see what’s new – and no inline place for people to comment.
There’s always facebook, of course – I see the Eggers Egg-Bot group is there, and it certainly seems to be underused, but then again it seems to be mostly for people who do major fancy egg decorating – rather than the kind of quixotic adventurers who may(?) be a good part of your constituency.