The reason I chose this plan over others with a real 0.993 m pendulum (which is what you need for an oscillation period of 2 seconds) powered either by a conterweight or a spring, is that it uses a short 0.33 m pendulum assisted by a simple 1 transistor battery powered electromagnet coil circuit to push a magnet on the pendulum ever so slightly to counter the inertia lost to friction. However the circuit does not control the accuracy or timing of the clock, but rather a weight adjusted up or down at the bottom of the pendulum to adjust the period of the oscillation.
Wow, that is awesome! So I wasnât crazy when I thought the pendulum as the power-source. I will have to look more closely at that Magica Wooden Clock! That looks like a really amazing power source with the electromagnet.
Well if you think about it, somewhere in your gearbox there will be an axle that is turning at 1 rotation per hour, and that is your minute hand. The distinction is all in your mind: Where does the gear drive end and the clock face start?
You can increase the runtime of your clock by adding more gearing to your gearbox, limited only by friction. Of course, the pendulum period has to be adjusted accordingly.
I went ahead and glued the wheels and pinions together to allow them to spin freely on the axles. I attached the face-plate (with some spare parts I had lying around) and cut out some frame braces to hold everything together.
I am really surprised at how well it all works together! I do not have a weight to drive it or a pendulum to regulate it yet, but the gears all work as expected. It has made for pretty cool clock model.
The escapement prevents me from spinning the gears forward (as expected), but it will let me spin them backwards rather easily.
I ordered some brass rods for when I try to make the real thing. I will use those for axles instead of the dowel rods and bamboo skewers I am using now.
It sure would be cool! Everyone loves a video of goodness put into motion!
It took me a bit because I wanted to replace the spare parts with printed spacers (and apparently videos are very limited here, I had to edit the video four times to get it to work!)
Edit: Looking back on this with what I have learned, the escape wheel and escapement ARE on backwards.
Yes, the model is made entirely of draftboard. I had a few nuts and bolts holding stuff together at one point, but I replace them with custom spacers and press-fit tabs.
The whole thing works WAY better than I ever expected. The hour gears stick a little too tight to the drive shaft, causing the minute hand jerk when it builds up enough torque to free itself. Other than that, if I put a pulley and pendulum on it, I think it would work (but I donât think it would keep time.)
If I turn the gears forward they get caught on the escapement and will be regulated by the pendulum. I did not expect it to be able to turn backwards so easily, that was just a happy accident for me
Right now the design (minus the pendulum and weight mechanism) all fit on a single medium Draftboard.
I was going to try to make it larger for when I really try to make a working clock, but this size might work. I just need to make a few adjustments and make sure I adjust for kerf with the sizing.
That is a good question⌠I donât know yet. I definitely want to experiment with acrylic too. The warping kind of scares me a bit, but it sounds like the draftboard will have that issue to, over time.
I have been looking at playing with some Delrin. I think if I want smaller gears that is probably the direction to go?
In all seriousness, the only experience I have was with a full size that actually used brass (looking) chains. Like a necklace. They sell that stuff on reels in craft stores and walmartâŚ
goodness put into motion!
medium Draftboard.
, but I am not sure if it would be long enough⌠(I can always extend it.)