When you have guests over for the holidays, don't cast pearls before swine. Make a 3D-printed bottle lock for the craft beers, and let your friends and family drink the cheap ones. Bah Humbug!

If you want to see me 3D model a version of this project in real-time, check out this webinar I led which was lesson 3 of the Hour of Making Webinar series.

You can also watch the other two lessons here: Hour of Making Lesson 1: Make a Wax Stamp and Hour of Making Lesson 2: Make a Christmas Ornament.

Step 1: Design

The first step in the design is to measure the bottle. The shapes of bottles vary pretty widely, but the caps seem to be totally standard. Because of that I decided to make the lock clamp onto the bottle cap, and left some wiggle room for the size of the neck.

I made the rough shape of the bottle, then designed the lock to be a clamp with a single 4-40 screw as the hinge part. The other end of the clamp has a hole that fits an off-the-shelf luggage padlock I found in a 6-pack at a hardware store.

I used Fusion 360 for the design because it's a great solid modeling tool. It has mechanical assembly functions that let me test out the motion and figure out if it would easily come on and off of the bottle. Fusion 360 is free for students and hobbyists, and there's a ton of educational support on it. If you want to learn to 3D model the kind of work I do, I think this is the best choice on the market. Click the links below to sign up:

Student/Educator

Hobbyist/Startup

Step 2: 3D Printing

I used a Makerbot Replicator 2, but this model would work with practically any 3D printer. When you model Fusion 360 properly, there is no cleanup whatsoever when you prep it for 3D printing. Just bring it into the Makerbot app, position it, and off you go.

This is not a simple monolithic object. There are "overhangs" because the hinge parts interlock and there are holes. So whatever printer you're using, make sure you use supports. The group of 6 took about 6 hours to print.

Step 3: Assembly

I designed it to use a 3/4" long 4-40 machine screw, washer, and nut to be embedded into the bottom of the print. The fit was so tight that the screw ended up threading into the plastic. The nut was totally unnecessary, and in fact it cracked the plastic when I hammered it in, so you could probably leave that out.