# Questions tagged [torque]

For questions about torque as it relates to electronics. Consider using in conjunction with related tags such as "motor" (and more specific motor-related tags), if applicable.

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144 views

### Reverse engineering a torque sensor

I am trying to reverse engineer a torque sensor. I have found the two data lines that are providing the torque value output to the ECU. Here are the waveforms that I have captured that show max. ...
49 views

I need to test several BLDC motors and their ESCs, primarily to determine the motor's capability and power consumption, as well as the ESC's ability to drive the motor at higher current. Aside from ...
140 views

### Transfer function of two frequency spectra

When you have two amplitude frequency spectra (fourier spectrum), in this case of a torque ripple, how do you define the transfer function (or the ratio) between both? How do you "divide" ...
150 views

### Testing DC motor with a torque wrench

How can I measure the torque of a stalled DC motor @ 6V using a torque wrench? I'm trying to test my DC motor with the torque wrench method (regular torque wrench used for cars).
1 vote
65 views

### Motor peak and continuous torque calculation

Given these motor characteristics for a BLDC motor ( maximum speed = 2000 RPM), what is the achievable continuous and peak torque with 24V input at very low RPMs (<50 RPM)?
1 vote
170 views

### Accurate Static Pulling (with electric motor?)

I am trying to see if I could accurately apply a static pull to a cord to create tension. I should not be measuring the tension directly, only be sure that the pull I apply is the force in Newtons ...
155 views

### Motor controller structure for constant torque starting and then switching to constant speed

I need to design a field-oriented-control (FOC) controller for a permanent magnet synchronous motor (PMSM) with position sensor. In the starting process where the motor goes from zero speed to rated ...
177 views

### Is the calculation of weight to be suspended inorder to produce electricity from an alternator correct or not?

I bought a alternator with the following specs: power: 5 hp rpm: 1800 voltage: 220V The formula for finding the horsepower is: horsepower= (RPM X Torque)/5252 By substituting the value of horsepower ...
217 views

### How reliable are motor power ratings through time (old motors vs new motors)?

I'm making this question here because I'm a little bit confused with what I've been seeing from some old and new 1/2 hp motors. I've bought a 1/2 hp induction motor (4-pole, single phase, capacitor ...
1 vote
228 views

### Achieving zero torque from DC motor

The current project I am working on requires a motor to provide ~2 Nm to a spinning shaft and then upon command provide ~0 Nm, hence acting like a bearing. The motor will have an attached encoder, and ...
210 views

### Measure torque with a BLDC motor

I'm trying to build a bench test in order to measure the torque required to put and keep in rotation a brake which function with friction. The rotational speed for this test is slow (15 RPM) to be ...
47 views

### Scaling up a Motor

If I take a DDR motor (Direct Drive motor like a washing machine 3 phase DC motor) and make a larger version of it so the diameter is 2x and the magnets and coils are correspondingly wider for the ...
263 views

### DIY Ebike BLDB motor controller, low torque, is it my motor?

I've designed a 3 phase inverter for driving a BLDC hub motor. The design (if anyone wants to look at schematics, is here). This works well, the motor spins up and down fine, no worries. However, if I ...
49 views

### Induction motors torque measurement

I am to calculate the running efficiency of a 3-Ph squirrel cage induction motor. I have the rated data for the motor. I have the load speed of the motor but I need output torque to calculate the ...
2k views

### Why are stepper motor phase currents a sinusoildal waveform?

I don't know if this is a really dumb question or not, but I've seen all kinds of torque, peak-current and RMS discussions related to current drive output for stepper motors. I acknowledge that for a ...
38 views

### Motor and Controller to spin Camera Array

I am in over my depth with respect to motors and drive hardware. Problem The motion control solutions I have tried have failed due to torque insufficiency and noise. Seeking I am seeking motion ...
537 views

### How to find BLDC motor power and torque rating with torque constants and other given parameters

I am currently working on simulating a solar pv fed bldc motor in simulink software. I have the datasheet values of bldc motor from a iet journal as Number of poles, P = 6; rated speed, Nrated = 3000 ...
320 views

### How to determine if a motor will be powerful enough to drive a drift trike

I am planning on building a drift trike and I am trying to work out the best motor to use that is right for my budget. I have seen: a 2000w (48v - 4300RPM - 4.44 N.m torque) a 1000w (48v - 3000 RPM -...
50 views

### Do eddy currents in a rotor core of an induction motor create torque proportional to the coil current of a squirrel cage?

In a rotor of an induction motor, the core plates and wire coil conductors have non-zero thicknesses. Therefore, eddy currents non-zero too. And they approximately proportional to the coil current of ...
4k views

### How to calculate torque constant and back EMF constant of a BLDC motor?

I have a BLDC motor to run for a fan. The parameters are as follows: Electrical frequency measured: 61.936 Hz Pole pairs: 8 Line voltage measured: 70.365 V RMS Line voltage peak: 99.51113732 ...
57 views

### through bore slip-ring torque rating

Planning to use a through bore slip ring for my project. Can some one please explain what does this rating mechanically mean. Torque ≤0.88 gm (for reference)
1 vote
395 views

### DC motor efficiency

I would like to build a Moment of Inertia machine: A machine that rotates an object (with a DC motor) and can also record the angular velocity and use this to find the moment of inertia. Initially I ...
119 views

### What's the difference between a direct drive/torque motor and a stepper?

A torque motor is 'either a rolled-up linear motor or a classic servo drive with a large number of poles'. As I understand it they are ironless 3 phase supply motors, though perhaps neither of these ...
283 views

### Is there a large difference between full-step and half-step stepper motors' torque at very low speeds?

I'm using a NEMA 23 for a solar tracker, which means my mechanism will move a single step every 5~10 minutes, and the step angle is 1.8 degrees which I need to bring down to 0.01 degrees. Now I need ...
256 views

### Slip Control vs Constant V/F Control for 3-Phase ACIM

I am trying to understand how is Slip Control different from Constant V/F control. If I need to control the speed of 3-phase ACIM then its slip would obviously change with its rotational speed then ...
146 views

### Is motor size an important factor in output performance or torque by keeping the same consumed power and voltage?

I have a problem comparing two sample motor's performance metrics . Two motors with same wattage ang voltage but different size. Big bulky motor Example: Bosch 1250 W Size Ref #1 1380 W Size Ref #2 ...
221 views

### torque-speed characteristics of induction motors

I have come across a website which says that zero staor resistance makes the maximum torque constant for different frequencies while keeping v/f ratio constant. And a non-zero stator resistance affect ...
1 vote
60 views

### Does "Torque control" using FOC consider input (battery) voltage drop?

All information related to Torque Control using FOC technique consider a current control, so they suppose a correlation between req_Id (Id desired) and requested mechanical torque. PI regulators ...
1 vote
497 views

### Difference between lower and higher current rated ESCs and electric skateboard questions

I am starting a project and would like to build an electric skateboard. Here are the specs for the parts that I have gathered so far: a. Two 90mm wheels that each contain a built-in BLDC motor. The ...
428 views

### Correct understanding of torque constant for BLDC using FOC

I have a BLDC motor with sinusoidal windings that I drive with FOC technique. With my recent knowledge earned by implementating FOC, I got confused with the typical motor constant given in ...
2k views

### Should startup torque be higher in value than full load torque in an induction motor?

I found out values of my 3 phase delta connected induction motor for full load torque, maximum torque and startup torque. My maximum torque was higher than my full load torque, but the thing I'm ...
170 views

### finding the right torque and motors

I am trying to find the right motors for the following case: I want to have a total of two motors on opposite sides of a board. The board will have a maximum weight of 150kg (330 lbs) and needs to ...
71 views

### Is power low for a high speed fan?

Got a question for my lab telling that the power consumed is low at higher speeds, why is it so? couldn't find any source backing up this statement too I did find this graph of torque vs speed, so I ...
311 views

### How to find the back-EMF constant of BLDC motor from a motor technical data?

I have a BLDC motor with these info (please don't pay attention to the striped column): How from these info, how can I get the Back-emf constant ? Is it just 36V/4krpm = 9 V/krpm ? Thank you a lot.
1 vote
106 views

### How do I find the torque of a simple electrical motor?

I created a simple electric motor following Khan Academy's tutorial, and now I am trying to figure out how I can find the torque from it (which should be quite small). Here is an image of the setup ...
51 views

### Maximum torque conditions

Suppose the following machinery : The induced torque is given by the following formula : where K is a constant which depends on the motor construction. Bs is the constant (in magnitude and in ...
158 views

### Torque in kg·cm vs N·cm (servo vs rotary switch)

I don't understand the different specifications of the maximum force of a servo motor vs the torque of a rotary switch. In the following example, there is a servo spec'ed at "Maximum Torque at 6V:...
1k views

### Torque control of a BLDC motor

Please forgive my lack of perfect electronics knowledge. I am here to learn. I understand I am clearly missing and misunderstanding something important. The aim of this question is to find out what it ...
122 views

### Designing a unipolar stepper driver using STM32 MCU, lack of torque

I am working on my first robotics project which will hopefully become a desktop sized KUKA iiwa. Unfortunately, I have only just completed the first year of my electrical engineering degree so have ...
64 views

### What is rotor torque in the stepping motor context?

I have the following datasheet for a stepping motor. I am wondering what "Rotor Torque" means in the stepping motor context. My first guess would be the torque produced by the rotor under ...
4k views

### Calculating the torque and RPM requirements for a DC motor

Say I'd like to calculate the motor specs required for lifting a 1kg weight at a rate of 1 m/s. How much torque and RPM should the motor have, assuming a wheel radius of 1cm? My calculations are as ...
249 views

### How do I calculate the RPM and torque of a 12 V DC motor that gets 5 V?

I have a PCB that outputs 5 V to each of the two motors. It was part of a robotics kit that included two 12 V 360 RPM motors. I want to attach a 12 V DC motor with 3500 RPM. How do I calculate how ...
1 vote
89 views

I work with compressors and usually the starting characteristic for fixed speed machines with starters is that the machine starts unloaded (star starter), after that the compressor unit is loaded and ...
35 views

### Can you design a DC motor with any arbitrary torque speed curve?

Title pretty much says it all. I have a low-rpm (30-160) and moderate-torque (2 N-m) application. These characteristics are pretty easy to hit with an off-the-shelf dc motor + gearbox. But let's say I ...
125 views

### Can not get maximum torque (stall torque) when current reach peak current

I am using FOC to control torque of 220V AC servo (SPMSM) with 36V power supply at low speed (100-200rpm). I tested with some servos (different manufacturers) which has specs as the below table. But I ...
1 vote
70 views

### Will running four motors (two high speed and two high torque) get the robot rolling? [closed]

I've been building a 2WD robot for 3 months now and been switching the motors frequently and been running into the same issue - low torque. I had these low RPM, high torque motors around and thought: ...
370 views

### What happens to DC Spindle horsepower at lower voltages?

I am running a shapeoko2 from inventables and bought a 300 Watt quiet cut DC spindle to run on it. The operating voltage range is 24V to 48V. My power source is adjustable to 48V but can only deliver ...
40 views

### VFD Driving a 40HP Inverter Rated Motor showing high Torque, Output Current at Low Speed

I am having some difficulty troubleshooting a Toshiba VFAS3-4300PC. I am using it to run a 40HP inverter rated motor that is driving a VRU Screw Compressor. I have the frequency range set for 12-60Hz. ...