Built this to stop my toddler from slamming his door and thus trapping himself in his room. I'm sure it has other practical purposes. It may be mildly overbuilt for its function but ragging toddler strength be strong yo! Built this around a residential hinge (diameter of 15mm). A bigger commercial hinge the model may need scaling. If you need something just to occasionally hold open a door that wont be forced closed by a little mini you, you can just scale down the model vertically in your 3d modeling software of choice. I used the CHEP Hyperfast Cura Profile found here ( [https://thangs.com/designer/CHEP/3d-model/Ver3.6%20Cura%20V5.0%20Filament%20Friday%20HyperFast%20Profile%20by%20CHEP-1002019](https://thangs.com/designer/CHEP/3d-model/Ver3.6%20Cura%20V5.0%20Filament%20Friday%20HyperFast%20Profile%20by%20CHEP-1002019) )  with my printer's retraction settings to make this down to a 2.5hr print on a Ender 3, just make sure to bump temps up to like 220-230 if your extruder starts sounding angry.  Printed at 0.32 layer height with some left over white PLA I had laying around 20% cubic infill.