RC SERVO REDESIGN
Time Period: October 2016 - December 2016
Course: Visualization for Design
Skills Developed: Critical Thinking, Drafting, Redesign
Software Used: AutoCAD
Project Background
I worked on a team with three other mechanical engineering students to redesign an RC servo, converting it to dual drive. We went through the design process up to creating drawings of the prototype. Our goal was to minimize production costs, increase energy efficiency, and design the servo such that both drive shafts spin the same direction. This is because when implementing multiple servos into RC products, the electricity is used less efficiently. When implementing multiple drive shafts, it is more common to have them rotate in the same direction as objects of symmetry. RC airplanes and RC cars require the same rotational movement on both sides of the line of symmetry in order to either move or perform small actions (i.e. move windshield wipers, eject airplane wheels).
RESEARCH
The initial step was to perform research on the current servo design. As a team, we took apart an existing servo to look at all the parts and how they work together to turn the drive shaft. We performed research online to understand how the potentiometer and PCB work.
We also decided it would be beneficial to research and identify uses for a dual drive RC servo. We found that remote control cars and airplanes are popular products that could dual drive servos. They currently contain two single drive servos which limits space available to other parts and increases the weight of the product.
SKETCHES
After taking measurements of the current servo, we created sketches for our design. The main goal was to minimize additional material costs and added size and weight. To do this, we designed the servo with three gear trains instead of 2 which are now symmetrically placed about the motor. This allows the drive shafts to spin in the same direction. We have kept the electrical components of the servo virtually the same; however, the motor is now connected to the middle gear train.
ENGINEERING DRAWINGS
The final step of this project was to create a book of engineering drawings that could be used for manufacturing. These drawings included full body assemblies, exploded views, and drafted drawings for each individual part that made up the redesigned servo.
Conclusion
In conclusion, using this redesigned servo is much better than using multiple servos for many reasons, the most important ones being:​ material/cost, energy efficiency, and packing efficiency.
The dual-drive servo deducts the additional motor, potentiometer, circuit board, and wiring that a second single-drive motor would require. The modified product’s casing will only take a volume about 1.3 times the original, while two single drive servos take about 2 times the original volume.
One motor and one potentiometer is used to do the work of what two of each would do if there were 2 single-drive servos.
The dual drive servo is more compact than using two single-drive servos. There is less material, so it takes up less space than 2 servos would take up to complete the same task.
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Were we to continue this project, the next steps would include 3D modeling and prototyping, testing, manufacturing, and supplying the product to distributors to sell.