Simple and Effective 3D Printed Ninja Door Lock for Children

In addition to being a 3D printing writer, I am also a childcare provider, and I am innately drawn to anything that promises to make caring for children and keeping them safe easier for caregivers. Some of the best children related 3D printed items are things like toys and superhero figurines, and that’s all really great. 3D printing brings out the child in all of us — in many ways. But what about the less exciting things that people use to create safe environments?

If you’ve spent any time around children, especially toddlers who love to run and move about, you know how fast they can move. And you’ll know how functional a door lock is if you’ve ever been in the unfortunate situation of caring for a child and suddenly not being able to locate them in the house! It’s a terrifying feeling because, if you just turn your back for one second, a child can move quickly to another part of the room or house– and you are left imagining the worst!

When it comes to keeping doors shut, 3D designer “bslayton,” or Ben Slayton of Nashville, Tennessee, has done us all a favor and went ahead and designed a very simple and practical “Ninja Lock” or Indoor Child Door Lock that slips over the door, placing the device near the top of the door frame. And even better, the designer has included a built-in mechanism so that little fingers can’t get slammed in the doorway.

“If you have kids, chances are they are ninjas just like mine,” Slayton describes. “These little ninjas will get into anything and everything (including taking a sharpie to your white kitchen cabinets). I designed this device that slips over the door (preferably near the top) and locks the door within the door frame so that we can stop our little ninjas in their tracks. It also has a built in mechanism to prevent smashed fingers.”

What I like about this design is it can hold a door cracked open at a width that children can’t fit through. So, for example, you cat could still get through the door, but your toddler couldn’t, and that is a very practical feature. Is it really that simple to keep children out of certain rooms? Wow!

This nifty device is printed with ABS, using 40% at a resolution of 0.30. You need to rotate it 90° on X axis so that it lays flat, and it prints without supports at an extruder temperature of 230° C, a bed temperature of 110° C without support or rafts.

This device is generating quite a bit of interest already, with 1240 views and 35 downloads on Thingiverse. If you’ve had great successs printing this item or just want to vote for a very functional and effective design, you can vote for it in the 3Dprinting sub reddit here.

Designer Ben Slayton has already tested the device out on his 2- and 3-year-olds, which is as good of a test as any!

Let us know if you print this design out.  Discuss in the 3D Printed Door Lock forum thread on 3DPB.com.