3D Printed Baby Mobile & How to Model Animals

In this Instructable I will show you how to make a 3D printed baby mobile with animals, which I made for my good friends’ baby. I was inspired by the super cute design of Joseph's "Birds Mobile", by Samuel N. Bernier, published by LeFabShop on Thingiverse. I used some of the birds in the design, but I wanted to add some more animals. So in this Instructable I will explain how I designed the animals in Solidworks, and printed and assembled the design.

I know Solidworks is not the best to use for modelling organic shapes, but since I was trying to design some more stylized animal shapes, it worked out fine. I designed a bunny, a sheep and an elephant for the mobile. I will show the detailed steps I used to create the bunny, but the other animals I made in a similar fashion. They can be downloaded from this Instructable as stl-file.Although I used Solidworks, I think the same approach can be used in other modelling software.

This Instructable assumes some knowledge of Solidworks, I won’t go into detail on how to use the features. For certain parts I feel more comfortable working with surfaces, although I’m sure a similar effect could be reached by using solids only. Since it is not a functional, engineering part, I didn’t bother too much with dimensioning everything correctly, I just eyed what I thought looked right for a more organic approach. After all, it is a bunny, it’s fine to play around and have some fun with it!

Supplies

- optional: modelling software of choice

- 3D printer with some fun filament colors

- wooden dowels

- glue

- string

Step 1: Step 1: Design and Set-up

The basic approach I used for the animals was the same: make a sketch of the design, divide it into body parts, make the individual geometry of these parts in Solidworks in a multi-body part on one plane, then move the individual bodies to the correct location and merge. This will become clear in the following steps!

First I made some sketches for the animals I wanted to include. I knew I wanted to use some of the birds from LeFabShop in the design, so I tried using the same round body language for all animals in order to match. I made sketches from the side and front of the animals, to use as a reference for Solidworks.

To make the bunny, I started by drawing the side of the bunny in Solidworks as a sketch on the front plane. I gave it some rough dimensions, but I didn’t bother too much. This sketch also shows the basic approach I used; a multi-body part, of which I could move all separate elements of the bunny (ears, paws, head, body, tail) and scale them up or down depending on what I thought looked right (obviously, I would not recommend this approach for engineering).

I made each of the elements separately as geometrical bodies on the front plane, and used the Body Move/Copy function to place them more to the outside and on the correct angles. It is possible to first draw everything, then move and scale, or do it as you go along. The advantage of first drawing everything on the front plane is that you can skip making a lot of auxiliary planes.

Since the bunny is symmetrical on the front plane, I only made half the bunny and mirrored it at the end.

Step 2: Step 2. Head, Body and Tail

The head, body and tail of the bunny are made by simple Revolves. It’s hard to see, but I made them slightly flatter than a sphere, because I felt otherwise the bunny looked a little too round.

Step 3: Step 3. Front Paw

Now for the front paw. The paw has a round tip and a straight ‘leg’. I first made a plane, parallel to the front plane, where I wanted the paw to be located. Note that I could also have drawn it on the front plane and used the Body Move/Copy function, as I do in later steps. The tip of the paw is a half sphere, which I made on the created plane by a Revolve. I then used a simple Boss Extrude from the flat surface of the half-sphere to make it interject with the body. In this step, make sure only to merge the Boss Extrude with the half-sphere, not with the body itself. This way, the paw can still be positioned relative to the body. It should however fully intersect with the body. I used Body Move/Copy to rotate it slightly outwards.

Step 4: Step 4. the Ear

This is where it gets a little more difficult. I wanted the ear to have a broader base with a slight triangular shape, that gets thinner and more oval towards the end. I’ve hidden the other bodies in order to show it properly. Basically, I am creating a 3D skeleton of the shape of the ear, which can be filled in using solid features and surfaces.

I traced the sketch outline of the ear I had already made in the first sketch. To keep it simple, I used the front plane. I made three planes perpendicular to the sketch. On these planes I drew the shapes I wanted the cross-section of the ear to be at that position, using splines. Because I’m going to use a Loft, I did not include the tip of the ear yet. For the Loft, I connected the three parallel cross-sections of the ear, and used the sketch of the sides as guide curve.

For the tip I used surfaces in order to control the shape exactly how I wanted it to be. Delete the top surface of the Loft that was just created to convert the solid to a surface, using Delete face. Use the edge and the sketch of the side to create a Boundary surface of half the tip. In the Boundary surface dialogue, make sure to set the start and end conditions to Tangent to face for the edge of the loft, and Normal to profile for the sketch. This will create a smooth transition with the other half. Either mirror the Boundary surface, or create another one for the other half of the tip. Use Knit surface to knit the entire ear together, and make it a solid.

Now the ear is finished, but it is still in the middle of the bunny and that’s no place for ears. I also felt like it was too small compared to the rest of the bunny. First I used Scale to make it bigger. Then, using Body Move/Copy, I moved the ear to the side of the head, and rotated it outwards. Make sure that the end of the ear is fully intersecting with the head, so it will be easy to combine them later.

Step 5: Step 5. the Back Paw

The back paw has a shape very similar to a bean, with tips that can be seen as spheres. Using the first sketch, I made two spheres with Revolves. Then, seen from the back of the bunny, I used Body Move/Copy to move the lower sphere to the left. In order to connect the spheres, I sliced part of them away first. I did this by making a sketch of two straight lines on the top plane, then using Split line I projected this line on the spheres. I deleted the two inner halves using Delete Face.

In order to connect the spheres, I made one more sketch with another ‘bean-like’ outline. This shows how the paws should look as seen from the top. Then connect them with a Surface Loft. Again, use Tangency to face as the start and end condition. Using Knit surface, merge the surfaces and make it a solid.

I wanted the bunny to look like it was jumping, so I gave the paw a flat surface on the top (I imagine in a real bunny this would be the foot sole). I sketched one line for a Surface Extrude, that cuts through part of the paw. Then I used Surface Cut to cut away the top part.

Again, I thought the paw looked too small on the bunny, so I scaled it up and moved it to the side with Body Move/Copy.

Step 6: Step 6. Finishing Up

It’s starting to look like a bunny! Once you’re satisfied with the position and shape of all elements, use Combine to merge them together. To make it look a little smoother, I added a large fillet around the neck, and some smaller ones on the paws, ear and tail.

Now it’s still only half a bunny… Use Mirror to mirror it on the front plane and merge the halves. Since I wanted to 3D-print it, I wanted a flat surface for it to print on. So I sliced the belly with a surface, that just touched the paws. Now it has a stable surface for printing, and the tips of the paws also touched the build plate.

Finally, I cut two holes using Cut Extrude all the way through, one is for the eyes, the other is a small hole to hang the bunny from.

Step 7: Step 7. Design and 3D Printing

Now it’s time to decide on the lay-out of the mobile. I sketched a few lay-outs to find what I liked. I ended up using:

- 3 wooden dowels

- 3 birds

- 3 sheep

- 2 bunnies

- 1 elephant

- 11 clips (as provided by LeFabShop, not in the picture)

The stl-files of the animals can be downloaded from this Instructable. They can be scaled up or down if preferred, it shouldn't affect the print. In the end I thought they were a bit small so I scaled them up. I used Cura for slicing and printed them with the following settings:

- 0% infill (to keep the mobile light)

- Bottom and top layers 1 mm

- Brim of 8 mm

- Supports touching buildplate

After everything is printed, assemble the mobile by gluing the birds on the sticks, and use the clips to attach the animals and the wooden dowels with some string. Balance the mobile by moving the clips with the animals to the inside or the outside of the dowels.

I think the result is super cute, and it made my friend very happy!

Side note: Even though I used PLA to 3D print the animals, I would not recommend hanging this in reach of a baby to prevent them from putting the animals into their mouths.