Móc treo balo gắn stud (Backpack hook for stud mounting)

I've made these in 85mm and 75mm and they fit most of my kids backpacks.  I made a 65mm, for my youngest kid (any smaller and some fillets need adjusting).  Overall, these details are easy to change from the Fusion 360 design.

My kids found that you can also throw a coat on top of the backpack too.  I'm not sure how well that will work long term, but keeps things off the floor so that's great!

If your slicer supports it, the 3mf files use fuzzy skin feature on the main backpack interface surface to reduce sliding, and ironing to improve the top surfaces.  This is completely optional, of course.