The Just-In-Case Belt Hook

thingiverse

This is a small, inconspicuous hook that you can wear on your belt and forget about. If you need to carry something and have your hands free, you can hang it from the hook and make everyone around you extremely jealous. Like really: I keep two of these hooks on my belt just in case. It fits on belts up to 35 mm wide and 5 mm thick. Here's what I've hanged from my belt hooks over the past week: Keys Hat Shopping bags (in a long checkout line, so I hung my bags from the hook and played with my phone) Cameras GPS receivers Power drills 2 kg demolition sledgehammers Clipboards Spools of string (by looping it through the middle) Note: Of course, use personal discretion when hanging anything from your hook. It's up to you whether or not you want to hang a $3,000 camera off it, but I personally wouldn't trust something 3D-printed with something that heavy and precious. My rule: If I can drop it, I can hang it. Print Settings: Rafts: None Supports: None Resolution: 0.2 Infill: 50% Notes: I've designed internal voids into this object (layers 16-35 if you're printing at 0.2 mm resolution) to prevent delamination in the Z direction and compensate for weak infill-perimeter adhesion, which was a common failure mode in destructive tests that I've done on these hooks. Your slicer settings need to keep these voids intact. (These voids are why the part takes so long to print, by the way.) In the case of Cura, go to Expert Settings (Ctrl+E) and uncheck Combine everything (Type-B). This will achieve this. Post-Printing: As with all wearable objects, it's a good idea to soften the edges with a deburring tool, craft knife, or needle file. Designing this object began with forming a specification: The hook should clip items in place to prevent them from coming out. Add some physical barrier to the inside of the hook to prevent items from being pulled up too easily. My solution was two-fold: Make a hollow tube and align it with the bottom of the belt loop. Then, take a strip and pair it with the tube, angling it so that the newly-formed hook would be narrow at the top and wide at the bottom. Crucially, the transition between the strip and the tube is not perfect. There's a shoulder left on the inside, which makes it harder to pull something out of the hook when it is being pulled away from your body (imagine that you've hanged your keys on the hook, and they're caught on a shrub). You need to push the keys into the back of the clip and then pull up to withdraw them. Cut an angle onto the top of the hook to narrow it, making it easier to insert narrow objects like key loops. Also, make sure that the hook is shorter than the belt loop to make it simpler to insert objects in general; simply push something against the back of the belt loop and then push down. I used internal voids for added strength: The top of the hook has a hole passing through it. The purpose of this hole is to 'weld' the multiple layers together, ensuring that this part will not delaminate. If you look at it in the layer view, the tip of the hook is equivalent to 100% infill because of this design feature even though the rest of it is only 50%. I used the same trick in the areas at the back and base of the hook too, here ensuring that the part could withstand flexing and that the hook was properly attached to the belt loop. Version History: v1 — 16 Oct 2015 Initial Release