Channeled Marble Towel Hook

My wife asked me if I could design and 3D print a “hook” to hang our shower mat/towel for drying.  I wanted something that wasn't going to protrude out too far from the wall or that something could be caught on.  After searching around, I discovered the idea of an internal ball hook and came up with this design.

This design utilizes a 15.8mm diameter glass marble, which I assume is a common size since I had several of them laying around.

I made this particular towel holder with 2.5mm in clearance which is the thickness of the border on my shower mat.  This gap should be enough to work properly with a standard bath or hand towel, as well.

Print Settings

• Vertical orientation (upside down with two prongs pointing upwards)
• Works best in PETG
• .2mm resolution
• 15% infill (gyroid)
• No supports, rafts, nor skirts

Print Notes

• Insert a pause at 50.00mm during printing in order to insert marble into model

Installation

• I used Gorilla Tough & Clear Double Sided Adhesive Mounting Tape along the full length of the back of the hook, peeled, and stuck to wall

How to hang towel

• Place the edge of the towel into the hood from below and lift up into the clamp
• Pull down on the towel allowing the marble to grip it and lodge into its lower position

How to remove towel

• Pull the towel upward and off to the side to dislodge the marble while sliding the towel away out of the hook