How To Make a Mobile
More than any other type of bird, gulls appear to fly just for the fun of it. While other birds always seem to have somewhere to go, gulls ride back and fourth along cliff edge updrafts and soar in thermals for no apparent reason other than that they love to be airborne. This is the effect that I was hoping to create with this mobile.
Andy Slater, a Hot Wire enthusiast from the UK who runs TerraGenesis, has put together this “how-to” for making a foam mobile. Though he used birds, you can make it unique by creating butterflies, stars, airplanes, hearts, Christmas ornaments, etc!
The gulls on my mobile are eight inches long, and in its entirety the mobile spans a massive 5 feet, yet because it’s made from polystyrol (aka Cellofoam, though if Cellofoam is not available, regular EPS foam can be sliced to the desired thickness using the Hot Scroll Table) and pine strips, the whole thing weights less that 1 ounce (30g) and is easily fixed to the ceiling with nothing more than a push pin. Of course you don’t need to make yours that big and you might prefer to make butterflies, stars, airplanes, or the various planetary bodies in the solar system. You could also do seasonal objects, from Christmas ornaments to Valentine hearts to Autumn leaves. The choice is yours!
Making a Pattern: I began by finding suitable pictures on the Internet, sketching them onto thin cardboard, and cutting them out with scissors. Once I’d got shapes that I liked for the body and wings of the gulls I pinned this cardboard template to my polystyrol sheet and cut out my gull shapes simply by running the wire of the Hot Wire Foam Factory Sculpting Tool around the edge of the card. I used 3mm polystyrol and cut three sheets at a time.
Having cut out the pieces for six gulls I attached the wings using low-temperature hot glue. Hot glue is ideal for this because it sets in seconds. If you use a slower setting adhesive then use modelling pins to hold the wings while the glue dries. (Please note low temperature hot glue often comes undone in warmer temperatures, i.e. near a ceiling where heat accumulates. We recommend using low temp hot glue for temporary tacking, but then applying a permanent glue like our Foam Fusion – see here for Glue FAQs)
Balancing the Models: Each model, be it a gull, planet, butterfly, or whatever, needs to be attached to a thread and I used ordinary white cotton. The cotton needs to be attached above the model’s center of gravity if it is to balance and the fact that the models are made from foam makes this easy to do:
Thread a needle and hang it from a door frame using a blob of Blu-Tak. The needle hangs straight down. Push the needle into model. In my case I pushed it into the the back of the bird somewhere near the back of the wings. The polystyrol grips the needle enough to hold the light weight of the model and just hang there. If it hangs straight: great, you’ve found it. If it doesn’t hang straight then try another spot.
When you’ve found the right spot, push the needle right through, secure the thread with a dot of super glue, and move on to the next model.
How to Balance the Mobile: Having balanced all of the birds on threads, the next step was to hang them on the ends of the pine strips and add a dot of superglue.
Now in theory I should have been able to hang each of these pairs from the center of the strips, but it would be foolish to rely on that. Of course if you models are of different shapes and sizes then they are unlikely to have equal weight. Once again though, we can do it by trial and error:
Take a pine strip and attach a model to each end. Now attach a loop of cotton to the top of your door frame with the strip passing through the loop. Start with the loop roughly in the middle of the strip and if it doesn’t balance, move the look towards the lower end. when you’ve found the balance point, use a dot of superglue to secure it. After that it’s just a question of how big you want to make the mobile!