Animated Sheep
An #EssentialMechanism Project
Turn the handle on the 1:1 Mesh Gear box to make the sheep animation play! I designed the Mesh Gear to add to the Essential Mechanisms range, when I made a video of the box it was difficult to see the vertical shaft rotating, so, to make it clear what was going on I added the sheep animation, more on which later.
The Essential Mechanism section on the www.robives.com website houses a collection of starting point mechanisms ready to be used as a launch pad for your own paper animation projects. The 1:1 mesh gear joins a couple of other mesh gears with different ratios that include 11:23 and 12:32. Turn the handle on this project and the vertical shaft turns at the same speed as the crank.
Starting with the 11:23 Mesh Gear project I planned to come up with some new ideas for the website, the very thing that the Essential Mechanisms are designed for! First things first, I got out my sketchbook and drew a few possible ideas. In the mesh gear projects there is a box with a crank on the side. As the crank is turned the vertical shaft coming out of the top of box rotates. The vertical shaft rotates at 11/23 of the speed that the crank is being turned or just under half speed. So with the question “What turns around?“ in my head I put together some sketches.
I really liked the idea of the record player - put a pin in that one!
I also liked the squirrels chasing each other around the tree, something I see daily close to where I live, look out for that project in the future. First though, making a record player sounded like an awesome idea. I ventured into town and bought a 7” single from the local charity shop. Making some measurements it looked like when I cranked handles on existing models I was turning the handle around twice a second or 120rpm (revolutions per minute) A 7” single needs to be turning at 45rpm so the vertical shaft turning the record needed to be geared down. By changing the existing 11:23 project by replacing the 11 tooth gear with a 9 tooth gear the ratio was pretty close.
The hole in the centre of the record was close to 7mm in diameter so I changed the vertical axle from 8mm to 7mm, fit everything in a box and made a turntable for the record to sit on.
The tone arm has a sewing needle to trace the spiral groove of the record and a paper horn for amplification.
It looks great… but unfortunately, as is often the case with early prototypes, there are a few problems. The sound from the horn is very faint, the sound from the mechanism is loud and with the crank turning clockwise the record runs in reverse. The first two problems I have some ideas for and I’ll come back to that in a future newsletter. The direction of rotation is where the idea for the 1:1 Mesh Gear comes from. I’ve set aside the record player project for the moment and produced this new essential mechanism.
By convention the crank handle on the side of a box is turned clockwise, this is the direction that feels right. The existing design of mesh gears has a drive gear turning clockwise with the gear on the vertical shaft meshing with the teeth on the top of the crank gear. The end result is that the vertical shaft turns anticlockwise when viewed from above.
By fitting the gear on the vertical shaft so that it meshes with the lower part of the crank gear, the vertical shaft can be made to turn clockwise.
I have put together a gear box as a downloadable project so that you can choose which direction you want the vertical shaft to turn. The project is available to at www.robives.com or if you are a paid subscriber to this newsletter the pdf file can be downloaded at the end of this page - thank you for your support!
I’ve also included a file with just the parts as this is easier to open in suitable editing software should you want to make any changes to the design.
As mentioned earlier, to enhance the project I made a little four frame animation of a running sheep.
I used a piece of software called Procreate Dream, an animation package for the iPad, the software is cheap ($20) but very capable and easy to use, I found plenty of online tutorials and although this was my first time using the software I was able to make this perfectly serviceable animation in not very long. There are blank animation strips in with the mesh gear project file ready for you to try your own animations.
I hope you have enjoyed following along with my design process a little. Make sure to subscribe to hear about further developments of the Paper Record Player and other new projects. There might even be a squirrel!