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12 votes
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Can RC servo motors continually rotate?

In a nutshell, servo motors and stepper motors are not technically the same things. The link you posted is only for servos and not stepper motors. A servo motor assembly does not rotate freely like a ...
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6 votes

Can RC servo motors continually rotate?

Whether a motor can spin continuously depends how is is constrained by other parts of the system. An rc servo like the MG995 will typically have a motor, a gearbox and a limited travel potentiometer ...
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5 votes
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What is the required theory behind building a robotic arm?

There are 2 (or 3, depending on how the planned lifetime of the robot is) thing thats you have to consider. Static load: The motors stall (zero revolution) torques have to be able to hold the weight ...
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3 votes

Smart Home Model with Raspberry Pi

Though, there is not much information about your servos let's assume that they consume at least 1A each. This value will probably be higher given that you want to move doors and that requires torque. ...
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3 votes

Minimising lateral drift in a PID (Arduino) controlled quadcopter using a 6DOF IMU

IMUs have accumulating error and can not be a reliable sensors by themselves if you want to measure velocity or even worse, position. I believe your safest bet would be doing a sensor fusion between ...
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  • 306
3 votes

Minimising lateral drift in a PID (Arduino) controlled quadcopter using a 6DOF IMU

Unfortunately, with just an IMU there's virtually no way for your quad to know that it's drifting so it can't stop it. For outdoor flight you can add a GPS to detect the drift. For indoor flight, ...
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3 votes
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Pulse Position Modulation as used in RC controls

Many (perhaps most) radio control transmitters multiplex all the "RC PWM" channels into a single physical wire, using a system called "RC PPM" (radio-control pulse position modulation). (a) (b) (c) (d)...
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3 votes
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Controlling digital servos

Digital servos accept the same pulse width and pulse repetition rate as regular analog servos. a b With many RC servos -- both digital and analog -- as long as the "frame rate" (how many times per ...
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3 votes
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2DOF arm with quick movement: Stepper, servo, or DC motor?

Servo mechanisms are not the "popular" RC-Servos (not-only). Servo is a closed-loop control, not only for motors. Even Steppers could or not be servo-motors. RC-servos are in major cases a DC brushed ...
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3 votes

Biped Robot not getting on one foot

You got the second picture by physically manipulating the robot to get the center of mass above the rotated foot. What you need to do is to get the robot to shift its own center of mass in a similar ...
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3 votes
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How can I use an RC servo to rotate more than 360 deg and still maintain positional accuracy?

While originally creating this question I ended up finding an RC servo that can do this. HiTECH makes an RC servo (HS-785HB) that uses a muti-turn potentiometer rather than a standard rotary ...
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2 votes

What to use as electrovalve?

Generally you won't need a servo. The more common way to throttle a flow is to use pneumatic solenoid valves (which are either open or closed) and control them with PWM. See (for example) this ...
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2 votes
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How can I power a wheel but let it spin freely when not under power?

You can use a magnetic clutch. When the strain on the horn passes a particular mark, it overpowers the pairs of magnets holding the clutch plates causing it to slip without damaging the gears. You can ...
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2 votes
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Finding the position of a servo

Servos are by definition, in the position you told them to go (or in a fault condition). This is the difference between a servo and a stepper. You tell a stepper to move 1 step at a time and do not ...
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2 votes

Pulse Position Modulation as used in RC controls

Multiple channels are time sliced onto "one-wire". The real wire count is usually three. Typically there is a positive voltage wire (may not be there depending on whether both ends have their own ...
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2 votes
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Overheating/Jamming MG996R servo

You might be driving the servo beyond its limits. As noted in the pololu.com article “Servo control interface in detail”: If you keep making the pulses wider or narrower, servos will keep moving ...
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2 votes

What is the required theory behind building a robotic arm?

It sounds like you are developing a robotic manipulator from scratch so I also assume you will be writing software for position control too. Both the design and control depend on not only the dynamics ...
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  • 1,357
2 votes

Smart Home Model with Raspberry Pi

Raspberry Pis can be used for a huge range of things! And I like your idea! Although, you could use an Arduino Pro Micro board as that has everything you need and doesn't have unnecessary items like ...
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2 votes
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Biped Robot not getting on one foot

You might be able to use the the opposite foot to begin the rotation of your chassis, but it will be dependent on your chassis and foot geometry. Using your photos for reference, the left foot would ...
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2 votes
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Mounting gear on a servo

The attachment of something that's screwed in is not so much the screw, as it is the friction between the material around the screw (the "faying surfaces.") If you have good friction, and the load/...
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  • 710
2 votes

Mounting on servo horn

While all sorts of things get used in experiments, screws really intended to tap into plastic have larger more aggressive threads than those intended to go into a pre-tapped hole in a harder material ...
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2 votes

Biped State Space Implementation

The problem with most papers about LQR controller is, that they are describing only the half of whole problem. The key aspect of understanding LQR is that an additional "Finite State Machine" (FSM) is ...
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2 votes

Why are some motor shafts stiff while others spin freely when not powered?

IMHO it depends on two factors: if there is gear on the servo (so to motor rotates fast, the result is slow precise motion with high force), then moving it manually even little means to rotate the ...
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2 votes
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Arduino RC Kids Ride-On car: wiring help needed

I suspect that you will need a more powerful motor controller. This one is a 10 amp controller, and I suspect that the motors will have a higher stall amperage than that. The RoboClaw 2x30 amp motor ...
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2 votes

Servo motor power consumption issue

Firstly consider the servo torque limitations, if loading increase from specified limit the it start stalling and even can gear get fail and burn servo itself, possibly. And another concern is with ...
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2 votes
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How should I power my servo motor with the Adafruit PCA9685 chip?

Have you tried to connect the PAD supplied with the HSB servo the fifth picture on this page? It is not necessary but in the case that your battery is fully loaded it an cause an overload if you don't ...
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2 votes
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How to balance a humanoid robot on one feet?

Humanoid robots balance and motion planning are not trivial tasks. I believe you will learn a lot if you read about Zero Moment Point (ZMP). Basically, it is a specific point of contact between the ...
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2 votes

Servo motor vibration problem

In my experience, when a servo is shaking, that's how it tells you its power source (battery, etc) is inadequate. Especially if the servo hums or buzzes at around the command frequency (50 Hz in your ...
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2 votes
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Can inferences about servo torque or applied force be made by measuring servo current drain?

Yes, measuring motor current will give you a rough indication of torque. However, there are some caveats. Any gear train that you have between the load and motor will decrease the usefulness of ...
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  • 5,215
1 vote

Is my servo fried?

Yes it's absolutely fried. Check the tech specs of your servo next time. Power requirement: 4.8V or 6V (from receiver) Power consumption: 6V 8mA (at idle)
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