# Questions tagged [motors]

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96 views

### How do DC motor parameters scale with motor size?

Consider the following DC motor parameters: Rotor resistance, $R\ [\Omega]$ Motor constant, $k_t\ [\mathrm{V/rpm}]$ Inertia, $I\ [\mathrm{kg\cdot m^2]}$ How do they scale with motor size? Do $R$ and ...
20 views

### clockwork motor output in joules formula

I'm trying to understand the output of clockwork coils in joules or watts for different coils. You know the pullback car or windup pocket watch mechanism. I have heard it also called power in the ...
136 views

### A round, plastic pinion in a lock?

I'm looking at a teardown of a Masterlock. The guts look like this What's strange to me is the black, plastic pinion that appears to be smooth and a strangely shaped cam: Here's the cam magnified: ...
36 views

### Finding Supply/Nominal voltage for Torque Motor BLDC

I'm a bit confused by torque motors datasheets as it never mentions any nominal voltage. I would like to run a torque motor on a 24 V battery. The required max torque is 150 Nm (=21000 ...
167 views

### PID control of a DC motor with PWM from Raspberry Pi - how to cross dead area?

I'm driving a DC motor (actually a linear actuator) with a Polulu motor controller from a Raspberry Pi. The motor drives if you ask for anything between 20 and 100% duty cycle, so there is a dead zone ...
144 views

### Quick return mechanism for spring-loaded screw

Looking for a way to convert rotary motion to linear, but it should take less energy to get back to initial position than when going from initial position to the end position. Specifically, a screw ...
90 views

### How to calculate torque requirement for vehicle with Mecanum wheels?

What are the changes specific to mecanum wheels when calculating torque requirements for a vehicle. I have the data for the vehicles mass, top speed and top acceleration.
77 views

### How do I calculate the velocity of the piston?

I have a system with a motor connected to the trapezoidal lead screw. The lead screw is connected to the tube which is connected to the piston. The piston has to pump 1000cc oil against a pressure of ...
144 views

### How does a two dimensional elevator work?

If you watch this video, you can get a sense of how an elevator can operate in two dimensions. But, what I can't figure out is how it is driven. If you consider a conventional elevator, there is a ...
64 views

Below I attached two BLDC motor commonly used for skate boards, I am confused with the calculation of stall torque for these two motors,What i need to know, What is the maximum weight lifting ...
48 views

### Rotating four cylinders with one motor/actuator

I have a setup with 4 cylinders placed next to each other in following configuration. The cylinders are made of .2mm stainless steel. I would ideally want to rotate them along their axis using a ...
299 views

### Angular Velocity of motor shaft as function of Angular Position

I have a set of shafts that need to be rotated at a high frequency (~1000 RPM) but not at a constant speed. That is to say, the angular velocity of the shaft needs to be a periodic function of the ...
40 views

### Standard name for “retargeting” behaviour in motor controller

Over the years I've encountered a number of motor controllers (e.g., controllers in the NI Motion series) that incorporate what I usually refer to as "retargeting" behavior. Specifically, if the ...
80 views

### How do I calculate the best mass for the highest linear speed?

I have a motor whose specifications say that its torque is 190g*cm. If I have the formula for the mass of the wheel vs radius, is there any way I can find the radius to get the best linear speed? The ...
56 views

### How are small refrigerator compressors started?

Small refrigerator compressors in the US generally all have exactly the same design and I am trying to understand their starting mechanism better. How exactly does it work? What I generally ...
340 views

### Upgrading to a brushless motor

I have a mini-lathe with a 500W 3/4 HP variable speed motor, that is run by a controller at two different gearings. However, even at the LOW gearing I find the torque to be a little inadequate. Is it ...
100 views

### Validation of transfer function

I have developed a second order transfer function model for a permanent magnet dc motor in terms of speed and voltage. I had performed open loop no load experiments on the dc motor and derived the ...
23 views

### DC motor Magnetic axis of armature winding vs EMF

When considering the cross section of a DC motor we have: I notice that the Magnetic axis of the armature winding is aligned with direction of the EMF that will cause the rotation. Is there a ...
45 views

### Problem with transfer function in DC Motor

I'm trying to verify whether the transfer function in this control diagram is the one stated in this document. I tried solving it and got this: Shifting the armature current $$I_a$$ feedback point ...
22 views

### Which type of motor can I use for my project?

I am working on a project of linear positioning where a bed is coupled with a motor driven high pitch multi-start back driving lead screw. I need the bed to be freely moving when the motor is not ...
55 views

### Need to produce vibration amplitude of 200 um (approx) at natural (resonant) frequency, can be any frequency between 100 to 150 Hz

In order to conduct study, I need to produce controlled vibrations with amplitude (maximum) approx 200 um (micro) at frequency between (100-150) Hz. Vibration amplitude must be controlled with input ...
64 views

### Measurement of ICE torque

I'm seeking a precise description of engine torque. We talk about torque in terms of the twisting force that the piston exerts on the crankshaft with a radius equivalent of the rod throw. Assume ...
21 views

### Correct terminology for a zero turn stator winding on a BLDC?

I'm designing a BLDC motor with some unique geometry constraints (~250mm long, ~45mm diameter with a ~35mm bore down the center) and am considering using straight copper bars carrying high current ...
22 views

### Calculating the proper power of a motor

I'm trying to build a filament extruder with some basic available tools and materials. Simply the main principle of the machine is to insert some amount of plastic raw material ( ABS in our Case ) to ...
178 views

### How to regulate torque/RPM on an IWD vehicle

Generally, I'm interested in simple (DIY) electric vehicle design problems. I saw some photos of electric vehicles as in the following pic: or also you could check this youtube video. The vehicle is ...
66 views

### Choose a DC Motor for a skateboard

My body weight and that of the skateboard is $M = 90\text{ kg}$ I want to move 10 meters in 4 seconds. \begin{align} x(t) &= (at^2)/2 \\ x(4) &= (a\cdot4^2)/2 = 10 \\ &= a\cdot16/2 = ...
505 views

### Determining brushed DC motor inertia for modeling a motor

I'm making an model of a DC motor, and following the guide for measuring motor parameters: I am having trouble measuring the motor's inertia, as the guide for this section is vague. This is a graph ...
60 views

### Spinning a balanced load with DC motor

Enclosed within a consumer electronic, I would like to spin a small balanced load. The device will be rotated relative to gravity, but no other direct forces will be applied to the load. A coreless ...
44 views

### Servo drive gear placement relative to the body

Is there a universal rule for servo drive gear placement? I'm planning to use this servo for a robotics project, but I need to know exactly where the drive gear is located relative to the body. The ...
21 views

### Carnot cicle problem

I'm trying to solve this problem in elementary Carnot cycle study: I have two (hot and cold) heat fountains of a motor, in air, at temperatures $T_a = 1500^0$C and $T_c = 10^0$C, respectively. The ...
37 views

### FOC current ripples with angle dependencies

I implemented the FOC (Field Oriented Control) algorithm to control a BLDC motor at low speed. A phenomena I observed is, that at different electrical angles, the torque producing current breaks down ...
424 views

### FOC algorithm for BLDC motor and rotor position estimation via IMU

I would like to implement the Field Oriented Control (FOC) algorithm on my STM32 board for controlling a 3 phases sensorless BLDC motor. By googling I found a very interesting Application Note from ...
55 views

### Feasibility of a motorized 3-axis gimbal for visualization

Recently some friends and I conceived of a method for visualizing in real-time the pitch/yaw/roll of an aircraft where a model aircraft is mounted inside a gimbal; then, the controller for the gimbal ...
33 views

### two parameter equation to approximate torque v.s rotor speed curve of AC induction motors

Like the title states, I am looking for a way to approximate the torque vs rotor speed curve of an AC induction motor using the standard specs given in a specs sheet: LRA Pull-up torque break down ...
111 views

### Motor for inverted rotary pendulum

I'm building a rotary inverted pendulum to demonstrate reinforcement learning principles, however I have little experience with mechatronics. I will be building something similar to this. However ...
366 views

### Gearing for Multiple Forward / Reverse on Single Drive Shaft

This model illustrates my question: Red is a motor Green is the drive shaft Orange are nylon straps Blue are spools for the straps I want to be able to drive multiple spools in multiple directions ...
13 views

### How to obtain transfer function of servo?

I am using a servo motor and controlling it via arduino. Servo motor is part of a control system and I have to use System Identification techniques in order to obtain the servo's transfer function. ...
16 views

### Rotating vertical pole setup

software person here, venturing for the first time in the design of a mechanical system for a hobby project. Please note I have some experience in disassembling, fixing, reassembling mechanical ...
50 views

### Calculating needed motor to spin a disk at low RPM

I'm designing a machine that I need to spin a horizontal disk at low RPM using a motor and gearbox. I'm not good at physics so I need help to find a motor/gearbox to fulfill my needs. It's a ...
16 views

### How To Obtain The Correct Differential Gears With Motor Shaft Adapters

My knowledge in gears in limited to their types (bevel, spur, etc). I am trying to combine the power/torque of two DC motors using a differential gear. I have a good handle on the idea and design ...
48 views

### Get engine rpm using accelerometer

I'm studying the possibility to read an engine RPM by reading the vibrations of it. Basically an engine is "oscillating" on a car chassis on all 3 axes (X, Y, Z) but mostly on the Y one. When ignition ...
30 views

### off-scale torque measured - what is my torque arm?

I have assembled a benchtop torque measurement stand for evaluating electric motor and controller efficiency. The motor is 49kV , 5kW brushless outrunner. Input power reading is taken from motor ...
21 views

### Generally speaking are inrunner motors better generators than outrunner motors or vice versa?

Using a motor as a generator but looking to test something I understand that outrunners have a higher torque but would that be neccesarily good for generating electricity or not?
17 views

### Hub Mount Motor to Flange Mount

I have spec'd out a pneumatic motor with acceptable torque for a tension application. The motor has a 1.25" hub with set-screw indent for it's mounting method. Since this a prototype system, I don'...
35 views

### Starting of direct current Motor

what happens if starting arm of starter does not return to "OFF" position after a temporary supply failure?
20 views

### Borewell motor water outlet adjustment

Recently we put 500 feet borewell in our area, it's hot summer season now. Person who drilled the borewell told me that we can get 1.5 inch of water now. During winter season we can expect at least 2 ...
22 views

This may be difficult to answer but, theoretically, if you had a car with a sterling engine that produces say approximately 300 horsepower how much of any specific heat source would need to be used if ...
57 views

### Is there a motor design where a rotor gradually moves into a stater?

I was wondering if there is a motor/generator design where the rotor moves gradually in and out of the stator along the axis of rotation, or the stator over the rotor. If so, I'd like some resource(s)...