# Tag Info

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### Using brushless motors for very high torque

Your expectations are rather aggressive for a DC motor. First - 40Nm (350in-lbs) is A LOT of torque! Ex: A max rated torque for 1/4-20 bolt is only 75 in-lb (8.5Nm). Second - The mechanical power ...
• 725

### Struggling to understand Jacobian Inverse Kinematics

You will find it helpful to keep the physical robot and the math separate. The kinematics equations map joint parameters (which are often grouped as a vector $q$) to Cartesian coordinates ($x$,$y$,$z$...
• 4,435
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### Choosing stepper motor for hand

I have used MicroMo's stepper motors in the past. You can find their information here: http://www.micromo.com/products/stepper-motors/stepper-motors-datasheets However, I don't know if a design ...
• 4,386

### What are the equations of a s-curve position path?

The S-Curve profile can have several divisions along the time axis 7 divisions as per this image. This example has a constant positive jerk zone, a constant acceleration zone, a constant negative ...
• 671
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### How can I draw a line using rotation of two circles?

Made a quick diagram and a couple of calculations in matlab, let me know if it works for you. First of all, I am assuming you are considering your piece of paper as your reference coordinate system (...
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### Will this have more or less lifting strength

Every action has an equal and opposite reaction. Each motor/joint in a linear chain of actuators (snake) needs to be capable of supplying the appropriate reaction forces. This mean that, if you have ...
• 16k
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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 ...

### Which kind of motors and how powerfull should they be for a robotic arm

This type of question "how much torque does my robot arm need" has been answered many times on this site: Simple equation to calculate needed motor torque Design and construction of universal robotic ...
• 5,855
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### What are the equations of a s-curve position path?

To come up with a mathematical expression of the position reference $x\left(t\right)$ as a function of time $t$, we can inspect the profile of the acceleration $a\left(t\right)$. It is piece-wise ...
• 4,005
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### Specification calculation for choosing a proper stepper motor for Ball Lead / Screw system

When looking for motors, you usually are trying to figure out specific things with specific requirements. Holding Torque Torque at Speed Resolution (for steppers) NEMA size Positional Accuracy vs ...

### How to know what type of stepper motors to use when designing a robot

Math is the short answer. You need to figure out what you want the motor to do, i.e. how much it needs to lift, amount of torque etc. You also need to consider how it is going to be powered. If its ...
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### How to make a stepper motor rotate and come to a position of certain degrees (say for 90 degrees) from any initial position?

You're in luck. Stepper motors do not have absolute positions. There is no 0-degree mark, nor 90-degree mark, etc. Everything is relative to the current step, so you don't have to query where the ...

### How to find Friction or Viscous force b (nmsec) in DC motor

When no other load is on the motor, any torque that the motor is producing is to overcome the friction. If you know how to calculate your friction from the torque needed to overcome it (I don't), then ...
• 331
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### What is the best way to plug in more than 3 stepper motors into a Arduino Uno board?

Each EasyDriver takes two digital inputs - step and direction. These do not need any particular protocol so you can use any pin capable of digital output. The Arduino uno has 14 digital outputs and ...
• 531

### 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

### How to reduce the small free rotation/movement of a stepper motor shaft?

Adding a worm gear to connect the output shaft to the load you are trying to move might solve your problem, since worm gear arrangements are "self locking". Here is a reference for you: http://...
• 186

### How to reduce the small free rotation/movement of a stepper motor shaft?

It's a geared stepper, which means that it's a stepper (64 steps, I gather) followed by a 64:1 (approximately) gearbox. What you're seeing is almost certainly backlash in the gear train (see where I &...
• 1,891
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### Which motor to use for self-balancing-bot?

40 degrees is pretty good. I believe that you need motors with more torque as well as more speed. Which means that you may also need a new motor controller. The motors I don't have the information ...
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### Struggling to understand Jacobian Inverse Kinematics

Without using the Jacobian, inverse kinematics provide joint angles to put the robot at a desired pose. But using inverse kinematics to move from one pose to another does not say anything about the ...
• 4,386

### Encoder attached to output of gearbox of stepper motor

Here is the response from stepperonline about their closed loop stepper controller. Glad to receive your inquiry. You can't install the encoder on the output of the gearbox. This is uncorrect and ...

### Why my stepper motor doesn't move when I attach a blade?

I will take a wild guess - your accellerating to fast for the mass of the blade / power of the stepper motor. You can check this by trying to step much slower - perhaps 1 step per second for testing
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### Stepper drive resolution

G'day, For question 1, your knowledge of the standard convention for notation is correct. However, it's worth noting that the listing for the gearbox ratio isn't 1:64, it's 1/64, which is a slightly ...

### How to make a CNC machine from scratch?

How does a controller translate a move x 20 units to moving the stepper x amount of steps and keep dimensional accuracy? If the CAD G-code says move 200 mm in the x direction, how to you translate the ...
• 6,662
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### Stepper Motor: Direct Drive vs. Belt Drive vs. Geared Stepper Motor

Vibration is a matter of optimal motion control problem, not the type of motor that is used (as long as you used more than 16 micro steps for your steppers). You already used AccelStepper which is the ...
• 1,567
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### Why use timing belt drives in Stepper Driven Robotic Arm

Even at zero speed, stepper motors have a max torque, called the holding torque. If your design needs even higher torque than that, you could use a bigger (heavier, more expensive) motor. ...
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### Which part handles the acceleration of stepper motors?

The short answer is all components in the chain you described have some effect on the acceleration. The CAM software defines the waypoint through which the tool center point passes. (Let us ignore the ...
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### How to attach plate to stepper motor?

Have a Google at double flat drive couplers, sometimes called oval, or dual drive flat. Something like this might do the trick: Also see How can I attach an arm to a double-flat drive stepper motor?
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### What type of actuators are needed for a high accuracy, low load weight robotic arm?

Ask yourself if you really need accuracy or precision. Because I think precision is easier to achieve than accuracy for most arms. I am not sure I would be as worried about the actuator as the gear-...
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