Hot answers tagged

17 votes
Accepted

How can I calculate the power and torque required for the motor on a wheeled robot/vehicle?

I laid everything out so you should only need to read it from top to bottom and look backwards for variables, never forward. I also tried to lay it out so hopefully you know where everything is coming ...
DKNguyen's user avatar
  • 5,496
13 votes
Accepted

Calculating torque needed to climb a graded hill

I think you're overcomplicating things. To push 85 kg up a 15% slope against gravity of 9.8 m/s2 requires a force of $$ \sin (\arctan (0.15) ) = 0.1483 \approx 0.15 $$ $$F = 85 kg \cdot 9.8 \frac{m}...
Dave Tweed's user avatar
  • 6,874
9 votes
Accepted

How to fix this gear

Oddly enough, this problem can be fixed using a set of car keys and your wallet. Here are the steps to follow: 1) put the keys in the ignition of your car, start it, and drive to the motorcycle ...
niels nielsen's user avatar
9 votes

Does a motor suffer damage when resistance to the intended motion is met?

The answer depends on the specific type of motor you intend to use, but in general: when a motor is loaded down, it draws more current, which means its windings get hotter at the same time that the ...
niels nielsen's user avatar
7 votes
Accepted

Rotating two shafts together - coupling rod?

The usual solution is to use gears, possibly with a toothed belt or chain to connect them. A single connecting rod like you show is not sufficient — there's an ambiguity when the rod is at the ...
Dave Tweed's user avatar
  • 6,874
7 votes
Accepted

Meaning of O-slash in data sheet about gear diameter?

In the lower right corner of the document/drawing, you can see four (or five) lines of text upward: UNIT: mm Another piece of useful information in the data panel is the scale, shown there as 3:1. ...
fred_dot_u's user avatar
  • 7,055
7 votes
Accepted

Building an ultralight electric hoist, what gearbox reduction / motor combination for torque / power requirements?

Relatively low lifting requirements (100 kg) Relatively fast lifting speed (80 fpm -> .4 m/s) The first part of your power calculation was wrong. There's no need to go into pulley diameters at ...
Neil_UK's user avatar
  • 405
7 votes

How do I start looking for a cheap encoder?

In the past whenever I needed a rotary encoder, I took apart a computer mouse. I do not know if they will meet your requirements, but there's nothing cheaper.
niels nielsen's user avatar
6 votes
Accepted

How does load force impact load inertia?

Let's first compute the model. The control design is a separate effort. The torque applied to the drum is $n T_M $, where n is the gear ratio and $T_M$ is the output produced by the motor. $T_M= K_T ...
Suba Thomas's user avatar
  • 1,971
6 votes

Why isn't it possible to build a car moved by wind power?

The fundamental problem in this case is that the turbine in not powered by 'wind' as such but by the relative motion of the car through the air. This is not 'free' energy, because the turbine must ...
Chris Johns's user avatar
  • 15.2k
6 votes
Accepted

How does a windshield wiper work?

For having dismantled a wiper motor once, The basic principle is exactly as shown on the video, but the wiper is then linked to the to the rotation point of the rocking bar and not to the bar itself. ...
Jonathan's user avatar
  • 334
6 votes
Accepted

Why do the lights dim when I turn on a mitre saw?

The wires in your home have resistance. Current going through those wires causes a voltage drop. The startup (inrush) current of electric motors can be several times their normal operating current. It'...
BillDOe's user avatar
  • 335
6 votes

Working out Motor torque

The biggest unknown you need to determine or guess is the coefficient of rolling friction. For reference, a coefficient for rolling friction of 0.3 is already very high and is for something like for ...
DKNguyen's user avatar
  • 5,496
6 votes

Does a motor suffer damage when resistance to the intended motion is met?

It depends on the specific type of motor, as @nielsnelson mentions, but it also depends on what you use to drive the motor. In general, a motor that's designed to run continuously isn't going to take ...
TimWescott's user avatar
  • 2,522
6 votes

Ways to brake an axle

In the wire & cable business, the device you describe is called a dancer, for the way its components move about while regulating the tension in a rope or wire being unspooled from a large coil. ...
niels nielsen's user avatar
5 votes

Are typical worms and worm gears self-locking?

The vast majority of worm gears are self locking naturally, it wouldn't be considered a special feature, just something you should confirm in your final design. Generally any single start worm screw ...
Ethan48's user avatar
  • 4,531
5 votes
Accepted

What would be needed to make a tesla fastest car in the world?

Maximum speed in a straight line is largely determined by the vehicles maximum power output compared to its drag although once you get past about 200 mph dynamic stability can start to become a ...
Chris Johns's user avatar
  • 15.2k
5 votes
Accepted

What is this contraption?

It looks like it might be a air-powered propeller. You pump up the bottle with air, and the high pressure is used to run a air motor that spins the propeller. This might have been part of a toy ...
Olin Lathrop's user avatar
  • 11.4k
5 votes
Accepted

Contrradicting answers for relation of speed of a motor with current

For a DC motor, speed of the armature is inversely proportional to current. But at the same time, we know that torque of the armature is directly proportional to the armature current. Since speed can ...
Brad's user avatar
  • 318
5 votes

Electric go kart

This cannot be answered as is because almost all the critical information is missing. Mechanical Power required to move to the go kart is determined by the force and speed required Motor Power can ...
DKNguyen's user avatar
  • 5,496
5 votes
Accepted

Lifting a cabinet using actuators or scissor lift

In a scissors jack design, items one and three, you'll have the least mechanical advantage when the assembly is retracted. Using drawer slides or the equivalent is a good idea, but will not provide ...
fred_dot_u's user avatar
  • 7,055
5 votes

What do I need to operate this motor?

I recommend researching motor driver circuits. These motor drivers internal has a H-Bridge design and have both direct on of digital signal to manage both direction (forward, backwards) and stop. You ...
Mahendra Gunawardena's user avatar
5 votes

Two 3/4HP / 500W motors to run in opposite directions, at precisely the same RPM, controllable from zero to 5000 RPM?

Connect them with gears and they will run at the same speed - any sensor / control will have an accuracy range
Solar Mike's user avatar
  • 15.6k
5 votes

Is there a difference between a "brushless motor" and a "motor without brushes"?

I suspect this is just a Brushless DC Electric motor What Dyson seems best at is marketing their tech and branding it to sound exciting.
Tiger Guy's user avatar
  • 6,793
5 votes

Inverting motor polarities automatically to close and open a door

If I am not mistaken, you can use an H-Bridge for that. If you are using an arduino for example, there are a few motor drivers like L298N which do exactly that job (control the direction and speed of ...
NMech's user avatar
  • 24.3k
4 votes

Actuator recommendation for oscillating motion of a 6 kg object

Vertical position is: $$ y = A \sin{(\omega t)} $$ If your frequency is 20Hz, your angular frequency is $2\pi f$, or 125.66 rad/s. If your max vertical motion is 30cm, then you could say it's 15cm +...
Chuck's user avatar
  • 3,565
4 votes

Type of motor for a small lathe

If money is no object then there are a lot of advantages to using a DC motor for a lathe. The ability to have continuously variable speed control is a huge advantage for a lathe. Compared to other ...
Chris Johns's user avatar
  • 15.2k
4 votes

Setting up a "pulsing" motor?

There are 3 obvious solutions mechanical : have a second, continuously running motor connected to either a cam or a rotary contact switch which makes/breaks the power circuit. This sort of approach ...
Chris Johns's user avatar
  • 15.2k
4 votes
Accepted

Technical obstacles in making a noiseless thermic motor?

Considering the nature of what an explosion is, I doubt we can just suppress the sound at it's source. The only way is to use a different motor technology. However, car manufacturers tend to isolate ...
MaximGi's user avatar
  • 318

Only top scored, non community-wiki answers of a minimum length are eligible