Those who like basketball in general and/or have a favourite team, might be interested to build this clock. It works as an alarm clock (obviously), looks (and behaves a bit) like a basketball (please watch the video). You can also put the logo of your favourite team on the dial.
The principal players are : "Styrofoam Shere" (outer diameter 100 mm, bought at a shop for handicraftsmen. You can observe the marking for cutting segments) and "Clockwork Mechanism" (ex-"Orange", joke) that I took from a cheap electric clock, its oscillator is quartz stabilized, though. Such clockworks are also available online.
Step 1: Cutting the Segments
You should cut two segments with their base diameters 80 mm. I did this job using an exacto knife, but you are free to choose the technique. You will need only one segment, it will be glued to the modified sphere after the operation described in the next step.
Step 2: Making a Pocket in a Segment
You will make a pocket in the segment that will be glued to the lower part of the sphere. The pocket is 15 mm deep and has diameter 50 mm. I gave the rough form to the pocket using cut the knife and refined it with sand paper. This work should be done carefully, otherwise the pocket could be deeper than the segment itself. Then I put decorative concrete into this pocket, thus making a counterweight. Then I weighted the segment and the reading was 25 grams.
Step 3: Making a Pocket for the Clockwork
You will make a pocket in the sphere where the clockwork will be placed. The clockwork that I used has dimensions 55 x 50 x 15 mm, I made the pocket accordingly (please refer to the drawing attached). You also observe a narrow groove on a side of the sphere, it's the groove for the 'alarm on/off' handle, its dimensions are 15 x 1.5 mm.
So, I made a 55 x 50 x 20 mm pocket for the clockwork. First, I drilled several holes about 18 mm deep with a 10 mm diameter drill bit ( I did it very carefully, holding the drill bit in my hand; fortunately, I drilled styrofoam, not granite). Then I cut remaining material with a knife and refined the surface using sand paper.
After this I made the pocket for the second counterweight, please refer to the drawing. I used a piece of M12 bolt, 50 mm long, its weight is 35 grams. The weight of the clockwork with the battery is 45 grams. I used a drill bit, a knife and sand paper to produce this pocket, the technique being the same as for the first pocket. The counterweight holds in the pocket because it's inserted tightly enough.
Step 4: Making Openings in the Sphere
I marked and drilled 3 openings in the sphere: one for the 'time setting' shaft, one for the 'alarm setting shaft', one for the alarm sound. The exact positioning of the holes depends on how the pins are situated in your clockwork. I also made a groove 15 deep and 1 mm wide on the side of the sphere where the 'alarm on/off' pin of the clockwork will be situated.
Step 5: Making Shafts and Handle
You observe the following items in picture 1: A - time setting shaft, B - alarm setting shaft, C - alarm on/off handle. I made the shafts of empty ball pen refills, and the handle of 0.8 mm diameter steel wire. I had to increase the inner diameter of the shafts to put them on the clockwork's pins (diameter 2 mm, length 3 mm).
When you need to take the clockwork out of the sphere to change the battery you slightly push on those shafts.
Step 6: Making Dial
The dial is cut of orange paper, its diameter is 80 mm. It's glued on a circle made of 0.8 mm thick plastic, this circle being then glued to the clockwork.
Step 7: Painting
I painted the sphere with orange acrylic paint and drew the lines with black wax crayon; then I covered the lines with colourless varnish. You can observe the result in the video.
Step 8: Video
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