Questions tagged [motors]
Questions regarding motors. All types of motors, their gearboxes, how to drive an electrical motor etc.
537
questions
25
votes
1
answer
85k
views
Understanding required torque for a motor lifting a weight
This is a continuation of me trying to understand torque and stepper motors in my other question. I'm trying to understand the torque a motor would be required to generate to lift a small weight, and ...
- 559
18
votes
5
answers
52k
views
Effective ways to drive a single shaft with multiple motors?
To head off the "why not use a bigger motor" question, I'm a high school mentor for an FTC (First Tech Challenge) robotics team, with a bit of a soft mechanical / hardware background. They're ...
- 281
15
votes
2
answers
3k
views
What is this small rotating part from a cell phone?
What is this tiny rotating piece of hardware that I found inside my Samsung GE1202? It has E9C written in blue on it.
- 153
11
votes
1
answer
628
views
Avoid snapping an electric cable from too much rotation
I recently built the basic construction for a crane out of lightweight material. Basically the head of the crane contains an electric servo motor which spins the head of the crane by pushing itself ...
- 387
10
votes
1
answer
4k
views
How to calculate Power of motor when used as a generator?
How can you calculate how much power can be generated by a motor when used as a generator (like a motor used in a wind turbine)?
Does the power depend on how fast the magnet is rotated? If so, is ...
- 313
9
votes
4
answers
2k
views
How does load force impact load inertia?
I am trying to simulate a winch as a speed-regulated motor that works through a gearbox to lift a mass. The output of the gearbox is a drum, which rotates to accumulate cable.
I feel comfortable ...
- 3,575
9
votes
2
answers
2k
views
Air compressor that doubles as a pneumatic motor?
I am working on a compressed air energy storage system. The size and weight of the system are heavily constrained; nothing should (ideally) exceed a few pounds. For this reason, I would like to store ...
- 93
8
votes
2
answers
3k
views
Why does public transport uses compressed air to open doors instead of electromotors?
System with compressed air seems more expensive and harder to build and integrate neither using simple electromagnetic drives to open public transport doors.
- 445
7
votes
1
answer
142
views
Which is more durable in sandy desert conditions: electric motors or hydraulic pistons?
If we have a tracking system placed in a tough desert environment with occasional sandstorms and temperatures that go as high as 50C, which actuator would be better: a hydraulic piston or an electric ...
7
votes
2
answers
212
views
Under what circumstances would one need or not need an electronic brake for a permanent magnet motor?
My company was asked to design a custom product several years ago. The original requester never bought it, but we've sold several a year through distribution. It's been a small side-line for a while, ...
- 1,675
6
votes
5
answers
28k
views
What is Starting Torque?
I'm having a hard time finding an answer from the internet. What does starting torque mean?
- 61
6
votes
4
answers
3k
views
What is the use of gears in a device with a fixed gear ratio?
From my understanding, there are two uses of a gearing system: to change the speed of output rotation (trading it with torque), and to change the axis of rotation. Now, in a car, for example, it is ...
- 221
6
votes
2
answers
15k
views
Calculating torque needed to climb a graded hill
I've been designing an electric skateboard which is driven by only one of the rear wheels (for the moment). As I was picking out motors for the board, I soon realized I would need to find a balance ...
- 67
6
votes
5
answers
1k
views
Ways to brake an axle
I am currently studying Mechanical Engineering and am doing an assignment where I have to design a wire rope tensioner where a wire rope is unspooled from a drum, but the wire has to be at a specific ...
- 61
5
votes
2
answers
4k
views
How can I calculate the power and torque required for the motor on a wheeled robot/vehicle?
How can I calculate the power and torque required for the motor on a wheeled robot or vehicle if a particular acceleration or movement up an incline is required?
- 5,237
5
votes
3
answers
2k
views
What would happen if we tried to run a motor in space when it is not attached to anything to provide support to it?
I know that when a motor runs it generates torque and that torque can be used to do useful work. On the other hand, the motor needs strong support that absorbs the reaction torque. In our case let us ...
- 53
5
votes
2
answers
1k
views
Lifting a cabinet using actuators or scissor lift
Disclaimer: I am not an engineer - just a DIY guy looking for some advice or help please, so please forgive me if I use incorrect terminology :)
I am building a cabinet that has a hidden inner cabinet ...
- 153
5
votes
1
answer
417
views
Power and motor current
This is a follow up question to my question here about torque and stepper motors.
There Olin explains:
Note also that torque isn't the only criterion for a motor. Power is
another important one. ...
- 559
5
votes
1
answer
71
views
Why would a specfication for a motor require that overtemperature protection be realized by modeling heat generation and not with an embedded sensor?
I'm reading the procurement documents for the R211 railcar contract, which is for electric multiple unit subway cars designed for rapid transit applications in New York City. The railcar's propulsion ...
- 153
5
votes
2
answers
143
views
How can I tell if a motor is defective?
I recently bought two 12 V DC motors from Amazon. After I received them today, I tried testing them. One of the two motors run fine but the other motor shows erratic behaviour. It gets very hot within ...
YaddyVirus
5
votes
1
answer
175
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 ...
- 540
5
votes
1
answer
590
views
Quick return mechanism for spring-loaded screw
I am 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 ...
- 93
4
votes
6
answers
4k
views
Does a motor suffer damage when resistance to the intended motion is met?
I'd like to create something similar to a hydraulic press. I know I need some sort of motor, but I was curious about a fundamental question about motors when used in a system where the force required ...
- 141
4
votes
3
answers
2k
views
How does a windshield wiper work?
Basic Googling on the mechanical generation of oscillating motion (moving something back and forth in the manner of a windshield wiper or a flapping wing) from a source of circular motion comes up ...
- 143
4
votes
5
answers
527
views
Preventing a DC motor from stalling
My team is trying to build a mechanical cannon for a final project for a course and we are running into some problems with our motor stalling.
Our motor stalls when the plate hits either side of this ...
4
votes
1
answer
783
views
Working out Motor torque
I need to calculate the required motor for a mobility scooter with the following user requirements.
The mass of the scooter with passenger = 120kg
Max Speed of scooter = 9Km/h
...
4
votes
2
answers
96
views
What do I need to operate this motor?
I am currently designing a tennis ball launcher. I am looking to use the friction wheel approach, where you have the ball passing through 2 spinning wheels and being launched by the frictional force. ...
- 49
4
votes
1
answer
302
views
What is this contraption?
If this is the wrong place for this question, please migrate it to someplace where it's more suitable.
So one of my old teachers from my previous school sent me a contraption to try and figure out ...
- 143
4
votes
1
answer
275
views
Are typical worms and worm gears self-locking?
Does anyone know if typical/common worms and worm gears self-locking (plastic or metal)? Are the self-locking ones specially designed (with specific angles) in order to be self-locking? By self-...
- 351
4
votes
2
answers
3k
views
How to connect a motor shaft to a plate
I'm trying to drive an aluminium plate using a motor via a 20mm-wide 2mm-thick stainless steel tube. The tube is driven by a 6mm motor shaft via a pulley and the torque will be around 5Nm at most. Is ...
- 1,033
4
votes
3
answers
737
views
Can Fast Fourier Transform be used to monitor for fault vibrations in a hard disk?
We want to monitor hard disks for present problems or pending failure.
Can the Fast Fourier Transform (FFT) of a given hard disk in question, then, be compared with a reference FFT for a perfectly ...
- 275
4
votes
1
answer
146
views
High RPM - Stepper vs Brushless Motor
I need to spin a threaded rod to raise a picture on a frame. The weight of the picture + the parts that it hangs on will be around 6 pounds. Two motors are going to be used to lift it via threaded ...
- 143
4
votes
2
answers
89
views
How do electric vehicles' motors run at high speeds above 10000rpm?
For example, for a squirrel cage induction motor, the speed of operation is given by
Ns = 120*f/P
depending on the number of pole pairs and supply frequency. Now the supply frequency is 50/60Hz while ...
4
votes
2
answers
2k
views
DC Motors synchronization
I would like to know how to synchronize two (nearly)-identical DC motors (approx. 1 Amp/12 VDC each) with permanent magnet, while they are driving on the same surface (railroad Track).
The problem is ...
- 41
4
votes
1
answer
2k
views
How to couple a motor to a screw drive?
I have a simple linear translation stage that is driven by a screw, and I would like to attach a stepper motor to the screw drive. The axis of the screw and the axis of the motor are approximately ...
- 6,386
4
votes
1
answer
55
views
Starter direction for methanol engine
I am having a small 2.5cc methanol 2-stroke engine that I am building an electric starter mechanism for. From my research I was under the impression that for a 2-stroke engine like the one that I have ...
- 195
4
votes
1
answer
441
views
What is the required torque to rotate a 50mm aluminimum plate of weight 100g?
I have a aluminium plate of radius 50mm and thickness 4mm. How much torque is needed to rotate it?
In case additional information is required :
I have a RS 380 motor, but I guess torque required is ...
- 41
4
votes
1
answer
3k
views
How to calculate if a motor is strong enough
I am building a machine for a project that should slowly tip a screen forward about 95 degrees, hold for a couple of seconds, and then slowly return to vertical. The design I am working on uses two ...
- 41
4
votes
0
answers
96
views
Is there any side effect to soft start an AC motor?
I have a ground to water heat pump for my home heating/cooling (scroll compressor). The 3-phase 15kW-peak motor can be soft started but this option is off by default.
I'm aware of all the positive ...
- 141
3
votes
2
answers
10k
views
Type of motor for a small lathe
I am working on a design for a small lathe that could double as a horizontal drilling machine like a Westhoff.
My plan is to have specific geared speeds, rather than continuously variable speed.
I am ...
- 1,625
3
votes
4
answers
140
views
How can you make a solid box jump up with no external forces?
Let's say I have a box lying on a flat surface.
Inside the box, I make a heavy mass hang from a spring attached to the top of the box.
If we pull the mass all the way down and let it go, I believe it ...
- 33
3
votes
2
answers
2k
views
AC Motor On/OFF Control using SSR instead of contactor
I would like to control a 1-phase 3HP motor using a SSR ( the reason being, I need to switch it on/off using a signal (0-5VDC).
Are normal SSRs (ex:Fotek 40A model) capable of handling the starting ...
- 113
3
votes
1
answer
80
views
Are all motors controlled with G-Code?
So I have laser cutter. And I am thinking about buying a control unit (this one, to be exact).
But my concern here is the following: If the input DXF file contains splines, they will be converted to ...
- 133
3
votes
1
answer
264
views
Why servomotor has such low torque compared with stepper motors?
It is easy to found stepper motors with torque over 2NM for a few coins, however, only expensive industrial servomotors achieve this torque.
Examples:
Stepper motor: 10usd for 1.3nm with 2.8V at 3....
- 338
3
votes
1
answer
39
views
Design decisions for variable speed motor switch settings (vs., say, rheostats)
Why do some variable speed motor switches have the highest speed setting next to the off setting instead of the lowest speed setting next to the off setting?
For example, most 3-speed household air-...
- 519
3
votes
1
answer
219
views
What sensors should be used to analyze vibration of a hard disk?
What kinds of sensors can be used to monitor the condition of a hard disk?
We want to be able to detect when a hard disk is not operating correctly.
Unexpected vibrations may be caused by spindle ...
- 275
3
votes
1
answer
249
views
A couple of questions about making an electric hobby car from scratch [closed]
So I'm a high school student doing some competition (a wallet-sized one, unfortunately) and I'm supposed to make an electric car. Think an RC-car, (about that size) without the remote control. I want ...
3
votes
1
answer
5k
views
What determines the maximum torque of a DC motor?
What determines the maximum torque of a DC motor?
How is this related to the equations
$$E=k\omega$$
$$T=kI$$
where
$E$ is electromagnetic force / voltage (V)
$\omega$ is rotational speed (rad/s)
$...
- 540
3
votes
2
answers
448
views
Pneumatic Actuators - System Reversibility. Is it possible to use an actuator to store energy?
I'm very much new to pneumatics and I was wondering if there was such a thing as a reversible pneumatic actuator?
I'm designing a system that has to be lightweight, pneumatic and use a mechanical ...
- 61
3
votes
3
answers
5k
views
How can I apply a load to an electric motor to simulate realistic conditions for an experiment?
I am trying to perform some experiments with a motor and I want to run it under realistic conditions (or at least not unloaded). Is there an easy way to load a motor?
A couple ideas I had include: ...
- 31