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35

The relationship between a motor's electrical characteristics and mechanical performance can be calculated as such (note: this is the analysis for an ideal brushed DC motor, but some of it should still apply to a non-ideal brushless DC motor). A DC motor can be approximated as a circuit with a resistor, and voltage back-emf source. The resistor models the ...

23

A motor with 1 kg.cm torque is capable of holding a 1 kg weight at a radial distance of 1 cm. Here is a diagram to explain. Torque is the cross-product of force and distance: $\tau = F \times d$. So the same weight, at twice the radial distance, will require double the torque. Note that the measurement 'kgcm' is 'kilograms-force × centimetres' and ...

18

Torque is a measure of "twisting force". Power is a measure of twisting force x speed. Torque is usually expressed as a Force x a distance So for the same Torque if you double the distance you halve the force to get the same answer. So kg.cm is kg force x centimetre distance. In fact kg are a mass and not a force BUT kg are sloppily used as a force in ...

12

This isn't a real answer, but is too long for a comment. Since you're in 9th grade (that would be freshman in high school here in the US), I'll explain what you did wrong instead of just downvoting your question to oblivion. Serious problems with your question are: "KGs" makes no sense here. You may think "Eh, capitalization doesn't matter", but it does. ...

11

Conceptually, you have to think about this slightly differently. The way I think you are thinking about this is kind of like torque in a vehicle. A car with more torque is going to accelerate more quickly and is associated with an increase in speed. In other words, you press on the gas pedal to increase the speed and you need torque to do that. However,...

11

After 4 years using and studying electrical vehicles I figured out that "gradeability" (ability to raise a slope of specific grade) depends on motor torque, and torque depends on current. Voltage instead "regulates" how fast a motor can run: the maximum speed a motor can reach is the speed at which the motor generates a voltage (named "Counter-...

11

Fix a lever of a precise known length to the specimen and add calibrated masses. Measure the deflection with a dial gauge. Perpendicularity might be a concern and could be addressed with geometry... However, the error that introduces is probably small compared to other sources. The sources of errors may well be worth checking. I know that for the ...

10

When the armature of a dc motor rotates , we call it torque because of rotational movement about the fixed axis. So where is speed? We don't call it torque, we call it speed aka rpm or rotational speed. The force that it takes to spin at a certain speed we call torque and usually, for a dc motor high speed means low torque and high torque means low speed....

10

The data is all given on the page you linked. The relevant quantity is the "Stall Torque", which is the maximum torque the motor is able to exert. Note - as the warning text, below the table, says, you should not plan to operate at this stall torque for more than a few seconds at a time. To convert stall torque to "a weight", take the stall torque in ounce-...

9

Torque is how hard you push, and speed is how fast it goes. In a electric motor, torque is proportional to current, regardless of the applied voltage. Think of a motor as the coils that cause the torque in series with a voltage source. The coils are always the same, and the torque produced by the magnetic interactions inside the motor are always ...

8

kgcm would be kilogram-centimeters, the motor is very old or the manufacturer does not like SI units. Anyway, 1kgcm is 0.09807Nm. The weight that your motor will be able to lift will depend on how big the pulley is. If the pulley is 2cm diameter (1cm radius) the motor will be able to lift 3kg. If the pulley is 20cm, the motor will be able to lift ~300g. If ...

7

In any motor, the basic principle is very simple: rotational speed is proportional to voltage applied torque is proportional to current pulled A 100 volt motor is a motor that can take a maximum of 100 volts, and a 50 volt motor a maximum of 50 volts. Since the 100 volt motor can take more volts, if all else is equal, it can give you a higher maximum ...

7

Since the table already has a crank, it's pretty easy: just use a spring scale to measure the force on the crank as you pull it through a complete cycle. Be careful to keep the axis of the scale at right angles to the crank arm at all times, and record the highest value you see. The torque is the value on the scale, multiplied by the length of the arm.

7

The motor controller acts as a buck type switching regulator with the motor windings acting as the inductor. Since the voltage across the windings when stalled is only the resistive drop from the current passing through them, there's no back EMF to overcome from mechanical work being done, the controller will be switching at a (fairly low) duty cycle that ...

6

Note that your question states that you want to reduce the starting torque, but you actually want to reduce the starting current. There are a few ways to reduce the starting current of a three-phase induction motor. In rough order of cost: Reduced Voltage starters These methods apply a reduced voltage (say 50%) to the motor on first starting. This reduces ...

6

It depends most on what and how you are fastening. Many different materials will have different properties. For example, the compressive strength of FR4 material is at least 460MPa, or 460N/mm^2. That number is one you want to stay well clear of, especially if you have multi-layer boards (since you don't know the exact specs of the prepreg your fab uses). ...

5

Assuming that you can find a gear reducer with an effective moment of inertia within the motor's range, you can probably crush soda cans with a 3v motor. At some point you're so geared down that the actual load is all but invisible to the motor, and you're simply driving the gear reducer. BUT, to crush a soda can this way, it might take an extremely long ...

5

You seem to be confused about what you want. If you want to decrease the motor speed, but you still want maximum torque, then you must apply full rated electrical power to the motor, and put a mechanical brake on the motor until it slows to the speed you desire. Or, you must somehow make your motor less efficient. I don't think that's what you want. Think ...

5

Calibration of equipment in manufacturing and other professional environments, when done "by the book", is governed by ISO 17025. This not only governs the procedures and methodologies, it includes things such as labeling and traceability. This standard should be a good starting point for your research into calibration.

5

Of course having the generator produce electrical power puts a load (torque in opposition to rotation) on the shaft. Without such load, there would be no mechanical power transferred into the generator, and it would violate conservation of energy by producing electrical power. Electric generators, which can be thought of as mechanical to electrical power ...

5

The short answer: they were both designed to do what they needed to do. One just cost more to do it. The long answer: Horsepower is proportional to speed. If you could spin that industrial motor as fast as the Tesla motor could spin, it might get close to the same horsepower - just before it shatters into a thousand flying pieces. The industrial motor was ...

5

Calculate separately the powers you need for acceleration (simple Newtonian physics) hill climbing (ditto, once you decide what speed you want up what gradient), rolling resistance (you'll need to research that, for the ground surfaces you're crossing. It depends on speed, ground surface, type of tyre, wheel size etc, you'll find plenty of info online to ...

5

I think you don't fully understand the specs of the motor. Stall Torque = 20 Kg/cm The unit is Kg*cm. And when a wheel of 4" diameter, i.e. 2"=5cm radius is directly mounted to the shaft, the "force" is 20Kg*cm / 5cm = 4kg. This means: If you put a string around the wheel and use it as winch, it could lift a weight of almost 4kg (8.8lbs) before it stalls....

5

In a permanent magnet or shunt-wound DC motor torque is directly proportional to current, and the torque constant (Kt) is the inverse of the velocity constant (Kv). If your motor does 12000rpm at 12V unloaded, then (assuming no-load current is 'small') Kv = 1000rpm/V or 105rad/s/V. The inverse of that is 1/105 = 0.0095N-m/A or 97g-cm/A. At 1.2A it would ...

4

Electric motors can be designed over a fairly wide range of voltage and current for the same speed and torque out. Just comparing the intended operating voltage of two motors doesn't tell you much about what those motors can ultimately do. Motors designed for high power do tend to work at higher voltages, but that is mostly so that the current can be ...

4

Rushing. More later maybe ... Note that "stall torque" is often used to mean locked rotor 0 RPM torque BUT you use it in the sense "dropout torque at a given speed". That's entirely fine as long as you note that some references will mean the former and not the latter. Criticism (kind / constructive) welcome. Written at a rush and unchecked. Better is ...

4

simulate this circuit – Schematic created using CircuitLab This is a steady-state approximation of a dc motor that works fairly well with some types of dc motors(see comment by supercat). Since steady-state, the armature inductance $L_a$ is neglected. We have the following: \begin{align} V &= \text{input dc voltage}\\ R_a &= \text{...

4

Assuming you are referring to the motor slowing when you increase the field current (in a motor with a separate field winding, rather than a permanent magnet motor: Remember what controls the speed of a lightly loaded motor : the speed increases until the back-EMF approximately equals the driving voltage. The back-EMF is generated by the motor acting as a ...

4

Relating a motor's current to a fan output airflow requires you to know details about the motor, the fan, the mechanical system surrounding the fan, and the ambient atmosphere. The motor current depends on the motor speed, as shown by a speed vs. current curve. The motor speed depends on the motor's speed-torque curve vs. the fan's speed-torque curve. The ...

4

I use a TackLife 1-4 Nm adjustable electric torque screwdriver. 1 Nm is too much torque for standard PCB material to handle before cracking if your screws don't strip. I'm assuming most PCB material is similar in composition. 0.6 Nm torque adjuster is required at work when assembling PCB components, 1 Nm for body/frame connections (metal on metal). Our ...

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