JOURNAL 10/10/25

Homework

This week I will research methods of raising / lowering the fins attached to the garment. This will involve considering high / low tech solutions. Perhaps linear actuators / stepper motors?

to-do

Research high-tech solutions (Compile list of components w/ pros & cons)

Research low-tech solutions

Reflections and decision-making rationale

• AC Servo (~$200)
• PROS
• Smooth operation: uniform torque across their speed range
• High torque density: Produce more power relative to their size and weight
• High precision and can achieve high speeds
• Do not generate radio frequency noise
• High precision and can achieve high speeds
• CONS
• High Cost
• Complicated drivers
• Power quality sensitivity
• Sustained overload can damage the motor
• Larger and heavier
• Less starting torque compared to DC motors

DC Servo (Brushless DC $100 - $500)

• PROS
• High Accuracy AND Precision
• Lower cost
• Simpler control systems
• Cons
• High precision and can achieve high speeds
• CONS
• Can also become unstable or cause damage due to overload
• Less precise speed control
• Power quality sensitivity
• Generate radio frequency noise due to brushes - can potentially interfere with LED strips
• Lower efficiency

Stepper Motors

• PROS
• Precision and control
• Holding torque: Can hold a load in place when stopped in place
• Simpler control systems
• High precision and can achieve high speeds
• CONS
• Low efficiency
• Electrical Noise
• Lower power density

I dont think it is a good idea to incorperate any motors into our design. The dress already has a significant energy consumption due to the lighting circuitry. Additionally, any actuators or motors may interfere electrically with the LED strips. Incorperating a motor into the dress will likely involve an overly complicated pulley system. This is unreasonable to put under the dress, and likely wont fit without aesthetic alterations. I'm inclined to lean towards a low-tech solution. Perhaps some clear fishing wire attached to the sleeves?

During the next group meeting, we must discuss where / how far the fins should extend. The fins will sort of resemble a type 2 lever. Anything beyond 90 degrees from the vertical axis will require significant upwards force. This will make it harder to conceal any cables / motors. For instance, if we want the fins to completely extend towards the shoulders, wire must be adhered to the ends of the fins to provice enough force.

I am also concerned about the azumuthal instability of the fins. In the upcoming weeks we must figure out a method of stabilizing the fins such that they dont wobble when extended. To proceed with this research we must develop the form/structure of the fins better i.e what will they look like, how will they recess into the dress, etc.

Selfies & photos of your work

Details of the time you spent

(10/11/25) --> (10/13/25 ) Research motor methods

(10/14/25) --> (10/16/25 ) Built test-wire apparatus

(10/17/25) --> (10/20/25 ) Calculated tension requirements for low-tech wire method

(10/21/25) --> (10/22/25 ) Made diagrams of low-tech implementation

(10/23/25) --> (10/24/25 ) Researched alternative low-tech drivers for fins.