3/18/2023 0 Comments Wooden work clock movementAn infrared emitter and receiver was added behind the back panel, aligned with two holes in the panel. The clock was running fast by about 18 seconds per hour. Stay tuned for several attempts to rescue the project. I was not about to commit the thing to the trash after all this blood and sweat of machining many parts. That seemed to sink this project altogether. The internal reduction gear was said to be 1:64. The specifications of the stepper motor were WRONG. What is going on? Hours and hours of Internet searches resulted in a surprise. The next morning, the mechanical time was several minutes faster than the RTC clock said. I calibrated the hands with the electronic time and walked away. Running the clock, things seemed to be operating just fine. The associated Arduino sketch is not included here for a very good reason. We need to obtain the date and time, control the OLED display and take actions as push buttons are pressed. Every second, 8 pulses are sent to the stepper motor which rotates the second shaft by 6 degrees. The basic functions in the Arduino sketch dealing with clock drive are very simple. A small OLED display is also used to show the date and time on the control box.įinally, 6 push buttons can be used to adjust the RTC and run the mechanical clock fast forward or fast reverse.įor the time being, ignore the section of the schematic labeled "IR Circuitry" The stepper motor (28BYI-48) is driven by a small controller board (ULN2003). It claims to accurate within less than a minute per year. This real-time clock (RTC) senses the surrounding temperature and uses a capacitor bank to switch in different capacitor values depending on the temperature. It obtains the date and time from a high-precision crystal clock (ChronoDot). The driver for the clock is based on an Arduino Uno. I know of at least one designer who cut out the hears with a scroll saw. This not intended to be a course on CNC routing. Usually, I prefer to make at least two passes, a rough cut with a larger end mill such as 1/8", followed by a finish cut with a 1/16" bit to achieve almost square inside corners.ĭesigning and machining a total of six wheel-pinion pairs took represents the major mechanical work and took several days. The latter program was used to make up the toolpaths for the CNC router. One image shows the CorelDraw final version of a typical wheel.Īfter finishing the drawing, it was exported from CorelDraw and imported into VCarve Pro. Final touchups were added such as the hub dimension and hold-down holes for CNC routing. The program outputs a DXF file which I imported into CorelDraw. It requires just the shaft distance and the number of teeth for wheel and pinion and it is done, well almost. The program "Gear Template Generator" by Mathias Wandel is a fabulous tool to design gears. It is rather a discussion on how to overcome obstacles and adversities when a parts supplier publishes erroneous data. Please note that this is not a complete Instructable in terms of showing all construction details. Next, we will look at the principle of operation. Studying the design, it was fairly easy to reverse-engineer the parts while maintaining total freedom for dimensions, design and machining software as well as the manufacturing tools. However, I commend DickB1 for writing a very detailed Instructable. If a published design limits you to proprietary methods, in my opinion, this is violating the fundamental ideology of this great site. Instructables caters to the do-it-yourself community. So, if you own or want to use some other machine, you are out of luck. The files cannot be converted into any other format. The design files can be purchased from CarveWright and can be used only if you own a CarveWright router. All mechanical parts of his clock were designed by proprietary software from CarveWright. However, in lieu of driving the clock with a magnetically pulsed pendulum, I used a small stepper motor.įirst, I need to get a major gripe with DickB1's design out of the way. This design was inspired by DickB1's Instructable (shown here at the bottom).
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