Wouldn’t it be fun to get a puppy for Christmas? Build a little puppy that comes out of a gift box when you turn the handle! This is an impressive mechanical contraption, but the mechanism is simple and it’s not difficult to build.
This LEGO® project works sort of like a jack-in-the-box. Turn the handle, and the puppy’s head is pushed up and out the top of the present.
The puppy has a gear rack attached to each side of its body, inside the gift box. The handle on the side of the gift is attached to an axle that also holds a gear on the inside of the gift. When you turn the handle, it turns the gear, which turns more gears, which push the gear racks upward.
If that doesn’t make sense, it will be more clear when you see the step-by-step photos below.
The mechanism is actually the same concept as the candy machine in Genius LEGO Inventions. We just built it to operate up-and-down this time instead of back and forth.
Ready to build your own adorable Puppy for Christmas?
Step 1: We’ll build the gift first. Create an 8 x 8 plate by putting smaller plates together. Or if you have one, use an 8 x 8 plate!
Step 2: Build three rows of bricks around the perimeter of the gift.
Step 3: Add a fourth row, and put a 1 x 4 Technic brick on each side. (Note the position of the Technic bricks.) Then gather the bricks shown.
Step 4: Slide an axle (3 studs long) through the Technic brick on one side, and attach a 1 x 3 liftarm with an axle hole and pin/crank. Insert a tan Technic pin (pin on one end, axle on the other) on the other side of the gift.
Step 5: Attach the 24 tooth gears. Slide the two 8 tooth gears onto an axle, 8 studs long with a stop on one end. Insert the axle into the Technic bricks as shown.
Step 6: Add three more rows of bricks, but don’t fill in the last row on the back.
Step 7: Build the top of the gift box. I used two 4 x 8 tan plates and covered them with the red and green plates shown.
Step 8: Find an axle (8 studs long), two Technic bush, two 1 x 2 light gray plates with a pin hole underneath, two 1 x 2 brown plates, and two 1 x 1 red Technic bricks.
Step 9: Slide these bricks onto the axle as shown.
Step 10: Attach the 1 x 2 brown plates/1 x 2 light gray plates to the underside of the gift box lid.
Step 11: Attach the lid to the gift box by attaching the two 1 x 1 red Technic bricks only. This will allow the axle to turn inside the Technic bricks, and the lid will open easily.
Step 12: Place a tan 2 x 4 plate on top of two 2 x 2 plates. Then find the bricks shown.
Step 13: Build the nose by attaching a 1 x 2 brick with two studs on the side. Add a 1 x 2 plate with one stud on top, and then attach a 1 x 1 black round plate to that.
Step 14: Place a 2 x 3 plate and a 1 x 2 plate behind the nose.
Step 15: Add the eyes and a 1 x2 plate with one stud on top. Then find the bricks shown.
Step 16: Add the 1 x 2 plate right behind the eyes. Place the two 1 x 1 bricks with a stud on the side on top of that. Then add the 1 x 2 brick on the back of the head.
Step 17: Finish up the head with a 2 x 2 curved slope and two 1 x 3 plates for ears.
Step 18: Find the bricks shown.
Step 19: Attach the head to a 2 x 4 plate. Then add the two brackets as shown.
Step 20: Attach the two 2 x 4 bricks and the 2 x 4 plate to the brackets.
Step 21: Add the 1 x 4 plate and two 2 x 2 tiles to the front of the dog’s body.
Step 22: Build the structure that the puppy’s head will be attached to. Grab a 4 x 6 tan plate, a 2 x 4 tan plate, a 2 x 2 tan plate, two gear racks, and a red 4 x 4 plate.
Step 23: This is what the back side should look like.
Step 24: Add a row of tiles around the top of the gift box. The lid won’t attach to the gift box because there is a space there, but the tiles just make it sit better.
Then slide the puppy into the gift! The teeth on the gear racks should mesh with the teeth on the 24 tooth gears that are inside the gift box.
The puppy should be able to slide all the way down in, like this.
Then turn the handle, and the puppy will pop up out of the present! SO CUTE!
If you’ve got a LEGO inventor on your Christmas list, be sure to check out our newest book! Genius LEGO Inventions with Bricks You Already Have is full of 40 amazing machines and gadgets to build, along with the science and engineering concepts behind the mechanisms.