Childproof Lever Doorknob

thingiverse

We have lever doorknobs throughout our house, partially for accessibility reasons, which also makes it easier for our clever toddler - and apparently cats - to open them. After researching commercial systems that try to prevent use of the doorknob completely, I realized they're ineffective at preventing kids from opening them. This simple device blocks the lever from being pulled down while still allowing it to move up freely. Our short little toddler isn't big enough to push the lever up, so he's kept out, while we giants are free to pass. This model is designed to fit a Schlage Flair with a round plate, but it'll likely fit many other models and brands. You may need to scale up a small percent if your doorknob backing plate is a different size. Critical default dimensions (scale up or down as needed): Maximum backing plate diameter: 29mm; Distance from door surface to back of lever: 47mm. Installation Instructions: Remove the doorknob. Slide the childproof device behind the doorknob. Re-install the doorknob, leaving screws slightly loose. Rotate the device so that the raised portion is below the lever and the lever is just barely in contact with the raised portion. Tighten all screws. Test to make sure the device doesn't slip. If it slips, tighten screws some more. If you can't get it tight enough for it not to slip, do not rely on lock for safety. Print Settings: Printer Brand: LulzBot Printer: Mini Rafts: Doesn't Matter Supports: No Infill: 40% Notes: I used 2mm walls/tops/bottoms and a pretty high infill in order to keep strength high.