5
votes
Accepted
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 ...
- 6,652
4
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 ...
- 16k
3
votes
Accepted
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 ...
- 705
3
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 ...
- 552
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 ...
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
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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 ...
- 123
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 ...
- 21
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 ...
- 1,991
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 ...
- 248
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 ...
- 1,377
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/...
- 720
2
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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
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 ...
- 121
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 ...
- 453
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 ...
- 572
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 ...
- 186
2
votes
Accepted
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 ...
- 66
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 ...
- 1,271
2
votes
Accepted
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 ...
Ben♦
- 5,825
1
vote
Accepted
Servo coupler size needed
RC Servos come with several different styles of exit shafts (often called splines due to the teeth that are cut into them). There are quite a few different styles. Tooth count (yes, 25T means 25 ...
- 705
1
vote
Accepted
How to create push and pull mechanism using Servo
Really simply - suppose you want to push-pull a switch.
You fix the servo and the switch (or any other manipulateable object) to some base.
Then set the servo to center position, put the plastic ...
- 453
1
vote
Accepted
DC Servos moving randomly
Short answer: your power supply is insufficient. You would be better off using a common wall wart charger.
If the servos are connected properly, they can move under three conditions: when they are ...
- 266
1
vote
Replace screws with motors!
You are best off using the servo's horn/hub (the plastic or metal disk or arm that you attach to the servo), and screwing the arm to the hub. You get buy some larger horns for fairly cheap, and that ...
- 266
1
vote
What happens when I connected my unpowered servo connector power wire to the powered arduino 5V pin?
Should be fine. If I remember correctly, the inputs to the ESC (more or less) control power mosfets. Putting input to a mosfet without power does not hurt it.
- 440
1
vote
Biped State Space Implementation
The servomotor is already a closed-loop servomechanism that uses position feedback to control its motion and final position. Your servo is an integrated servomotor, and then it contains the following ...
- 166
1
vote
Mounting on servo horn
With plastic holes especially on Servo Horns, the best solution is to use screws that are slightly bigger than the hole. Depending on the strength needed for this connection there are two methods ...
- 70
1
vote
Adafruit PCA9685 servo driver connected to Beaglebone Green Wireless generating erratic movement when driving multiple servos
The movement you are seeing is what I would expect to see if your ground was rising becouse of current draw. Basically as you turn on more servos you will see there current draw will make the apparent ...
- 1,919
1
vote
2DOF arm with quick movement: Stepper, servo, or DC motor?
any times when people say "servo motor" they are talking about the model airplane style square black plastic box. That is not what you want here. You would be looking at the industrial type servo. ...
- 446
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)
- 11
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