Fucking Machine Design
The glorious fucking machine is a popular project, and one solved in many different ways. Some of the common problems include range of movement, motor power, motor control, and many others.
Contents
Sex Machine Design Challenges
Motion Source
| Prime Mover | Advantages | Disadvantages | Learning Resources |
|---|---|---|---|
| DC Motor |
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| Stepper Motor |
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Jeremy Fielding - Beginners Guide To Using Large Stepper Motors: #087 |
| Servo Motor |
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| Pneumatic Cylinder |
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Mechanical System
Rotary to Linear
Most motion sources described above start often with a rotary motion. Generally, most machine designs will want to convert that rotary motion to a linear action. There are a few ways to accomplish this.
Crank
A fair number of machines solve the problem of converting a rotary motion to linear using a crank. This crank is often in the form of a disk. Attached to this will be an intermediate linkage which then attaches to a final shaft. The final shaft is constrained to a single plane, and the intermediate shaft allows for the change in angle as the crank shaft rotates.
| Example of Crank Mechanism |
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The stroke length is 2x the radius of where the intermediate shaft connects.
The force of the motor is reduced as this radius is increased.
Rack and Pinion
The rack and pinion setup is like a spur gear, with the larger gear laid flat. This is useful setup that has some control challenges.
Notable Uses:
Linear Motion Control
With the rotary motion made linear, generally there is a need to constrain the motion.
Linear Rails, Drawer Slides
Control
Simple power controls
DC motors are widely used because of their ability to be easily controlled. Voltage applied to the motor will start and maintain motion. Reversing the polarity of the voltage supply will reverse the motor.
Most sex machines utilizing DC motors will incorporate a speed controller. DC Motors speed control is accomplished by varying the voltage to the motor. DC motors described in this section are assumed to be Brushed Permanent Magnet DC Motors. Although the concepts are similar for other types of DC motors, there may be some specific challenges related to other configurations. Brushed Permanent Magnet DC Motors are the most common to be found in hobby sources, however brushless motors are now common in tools. These motors are usually AC Polyphase Permanent Magnet motors and require an appropriate controller to operate.
DC Speed controls can be found from many online retail sources, this allows control of DC motors without having to build your own controller.
Sizing A DC Speed Controller
The speed controller will have to operate at the correct voltage for your device. Often the DC controller is separate from the voltage source, so it will have a range of allowed voltages. Common voltages for hobby motors are 12vDC and 24vDC. These voltage levels are safer under normal circumstances. 12vDC will be most common and recognizable for hobbyists, however as 24vDC devices are common in industry it is possible to find many options.
The power rating of a DC Speed Controller will be expressed in watts or amperage (current). Watts are (in the simple form) [ Voltage x Current = Watts ] so it is possible to work with either value. The amperage of the motor will be specified as Full Load Amps (FLA) or Watts or Horse Power. To convert from HP to watts, multiply by 746.
Example;
- 1/4HP motor rated for 24vDC is [0.25HP x 746w = 186.5w]
- This lets us calculate the amperage at 24vDC, [ 186.5w / 24vDC = 7.8A ]
- For this example we would need a controller capable of at least 7.8 amps at 24vDC
- It is important to have additional current capacity, so it would be advisable to multiply the required by at least 1.25, giving us 9.75A minimum design requirement.
