Miniature Tabletop Clock

I wanted to create a miniature tabletop clock to send to my high school engineering teacher as a final gift before I moved off to Purdue University this fall. So I took apart an existing watch that I had (parts found listed below) and I modeled all of my pieces through Fusion 360 to create a miniature clock for my Project Lead the Way (PLTW) Engineering Design and Development (EDD) class.

(I am entering this competition as a current student of Brownsburg Highschool)

Needed Materials:

1x GL-22 Watch Movement

1x Watch Battery

1x Watch Stem (typically included with movement)

1x Set of 0.7 and 1.0mm watch hands

1x 3d print of the EDD clock

1x set of 28x37mm glass

Needed Tools:

3d Printer

To make my watch movement work I had to first find the type of watch movement that I would use in the project. The one I found in the watch I had was a Miyota GL22 watch movement.

Once I Discovered this, I researched the part and found the technical drawing of the piece which is pictured above. Then I Recreated the part in Fusion 360. However, you cannot just simply recreate a part put it in a box and call it a day. Typically, 3d prints require a tolerance of about .3mm on either side to accommodate for this such as pillowing (printing your plastic too hot) or other inaccuracies.

So, I Created a piece I saw fit and then fine turned the measurements through a series of 4-5 test prints and eventually came up with the drawing to the right of the technical drawing that I copied.

The glass was an overall simpler process than the movement in finding the actual dimensions. This is because I didn’t have to look us the actual technical drawing of the piece I was measuring. Instead, I just used the dimensions of the piece that were listed on the website that I ordered from. 

The dimensions were listed online as “37.00mm Length – 28.00mm Width 100degrees” It also stated that the piece was 1 mm in thickness.

Through this information I was able to come up with the following drawing.

After I came up with the exterior dimensions I extruded the piece to 28.6mm. This accounts for the need .3mm on each side of the piece so that it can snap in place.

After this I created the exterior of the shell used as the EDD clock.

As a note this piece snapped in place on the first try and did not require a redesign to function.

Once I had a functioning part for the watch and the glass then I combined the two pieces to create a coherent “Clock.” The design features a EDD lettering so that you are able to tell what class this is for. Additionally, I added holes in a circular pattern so that you can tell what time it is. 

There is not a dial on this project because the printers at school are not able to print with the precision required. The piece required to hold the dial in place is smaller than the nozzle on the printer. So, I left the dial out.

Also, I think that it looks cool without one.

Then I added fillets and an angles base so that you can tell what time it is easier when the watch is laying down. Additionally, the fillets make it to where you are less likely to chip away pieces over time since the edges are rounded. The overall design is pictured below.

Prepare the watch movement and place it on the work station. Grab the watch stem and place into the movement. Attach the watch hands onto the watch movement. Once you have the hands on and the stem inserted attach the battery to the movement so they time aspect of the clock functions as needed.

3D print the files to prepare the remaining pieces to be ready to print.

Note: this project doesn't use glue so tolerances are generally pretty tight. You may need to sand piece to get to proper tolerances (should only be minor.)

The final Step for assembly requires you to to insert the watch movement into the case. Once this is done you can stap the glass onto the piece and then you are ready to enjoy your newly converted clock!