Questions tagged [motors]

Questions regarding motors. All types of motors, their gearboxes, how to drive an electrical motor etc.

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How can I map a global spherical position of a central normal vector to the rotation of 2 perpendicular motors?

I have a machine that rotates two concentric frames. The outer frame has a motor that rotates it relative to the global y-axis, and the inner frame has a motor that rotates it about the outer frame's ...
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4 votes
0 answers
77 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 ...
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4 votes
0 answers
79 views

Etymology of the term "journal bearing"

Typically the word "journal" refers to a collection of written records, experiences, or transactions. However, there is a common type of bearing known as a sleeve bearing, radial bearing, or journal ...
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4 votes
1 answer
462 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 ...
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3 votes
0 answers
127 views

PMDC Motor Characteristic Graph

I am trying create a graph similar to as shown below. However, I am confused as to how the torque is related to the characteristics. The graph that is to be replicated for certain parameters: The ...
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3 votes
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162 views

Is having a keyway in aluminium for 30Nm a bad idea?

I'm designing an aluminium shaft hub for a 16mm keyed shaft with a maximum torque of 30Nm. However, stress analysis tells me that the keyway can suffer too much stress: If my understanding is correct,...
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3 votes
0 answers
63 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 ...
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3 votes
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57 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 ...
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3 votes
0 answers
143 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: ...
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3 votes
0 answers
594 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 ...
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2 votes
1 answer
83 views

Calculation for Motor Selection

I need help with the selection of a motor and a motor driver I need to spin a 700g (65mm radius) round ball at 35,000 RPM. I need to bring it up to speed slowly, so I also need a motor driver/speed ...
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2 votes
2 answers
91 views

how much power is needed to move a linear axis

Ι need help calculating the power usage for a linear axis motor. it must move up and down at a maximum speed of 0.5 m/s a load of 50 kg What I did so far: The load (i.e. weight) acting on the motor ...
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2 votes
0 answers
427 views

Advice on spring launcher project

I found an ingenious design of a spring ball launcher on grabcad and I'm interested in adapting it to accelerate a $43.7 \mathrm{~mm}$ diameter, $45 \mathrm{~g}$ golf ball enough to reach $65.5 \...
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2 votes
0 answers
50 views

Overcurrent protection, limit for nominal current or stall?

Background: I'm currently working on a robotics design that will drill through soil. I have selected a 48V motor who's nominal current is 3.17A and has a stall current of 42A. I will be driving the ...
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  • 331
2 votes
3 answers
89 views

Relation between armature voltage and mechanical power in electrical Engineering

I am searching for an effect chain that leads to the mechanical power $P_{mech}$ of a DC motor, starting with the applied armature voltage $U_{A}$. My request also includes all the electrotechnical ...
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2 votes
2 answers
85 views

How can I model a hysteresis curve from data?

I have the task of modeling the current to torque mapping for a given motor. I have an experimental set up where I can retrieve current, torque pairs. Now my initial approach was to model the ...
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2 votes
0 answers
822 views

how to calculate required torque and rpm to through a 160 gram cricket ball horizontally at 160km/h velocity?

I am going to design a bowling machine. In this design, I'm going to use two motors that are being placed vertically and their shaft are attached with two horizontal identical wheels with a space of ...
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2 votes
0 answers
77 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 ...
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2 votes
0 answers
236 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.
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2 votes
0 answers
137 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 ...
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2 votes
0 answers
70 views

Mechanical engineering, Please help me finding the torque and answering other doubts too

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 ...
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2 votes
0 answers
461 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 ...
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2 votes
0 answers
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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 ...
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2 votes
0 answers
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 ...
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2 votes
0 answers
81 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 ...
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2 votes
0 answers
60 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 ...
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2 votes
0 answers
179 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 ...
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2 votes
1 answer
56 views

What will happen if we place a couple of separate, small stators around a long rotor instead of 1 large stator around a short rotor?

My original theoretical consideration was using the electric motor's rotor as drive shaft in a car. It led me to this question: "What will happen if we place a couple of separate, small stators around ...
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1 vote
0 answers
40 views

Why does an electric motor, of 800 kW at 400 V, have 7 connectors for power cables?

I found a Vybo electric motor and noticed that it has seven connectors for power cables. I also found a Variable Speed Drive, Altivar Process ATV900, System ATV960, 800/630 kW, 400 V and its datasheet ...
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1 vote
0 answers
40 views

Electromagnetism - DC Motor Design Question - EMF/BACK EMF

I'm not gonna lie - I don't have enough knowledge about EMF and Back EMF so I need you guys , my friend will soon build a DC motor for me but I currently have no idea what design will produce high ...
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1 vote
2 answers
119 views

Torque Required From Motor For a Project

The device I am building is responsible for supporting 200 lbs and is required to accelerate 10 feet per second. The device will have two 8 inch diameter wheels. I have worked out what I believe to be ...
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1 vote
0 answers
33 views

Equations of motion in matrix form and energy consumption

I am working on Lagrangian derived high-dimensional motion equations for a robot in matrix form. The structure of such an equation is known: $M(q)\ddot{q}+C(q,\dot{q})\dot{q}+G(q)=0$ In here, $M(q)$, $...
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1 vote
0 answers
66 views

How to design an outrunner BLDC motor

I've difficulties to find a good documentation or a book to how to design an outrunner BLDC motor. My propose is, defined RPM and approximative kW and some other parameters, which are calculation ...
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1 vote
0 answers
52 views

What are some techniques for improving stabilization given a mechanical time constant?

Problem: I have a self-stabilizing system that utilizes an intertial measurement unit (IMU) attached to the hull of a vessel. The system self stabilizes by performing matrix rotations based on the ...
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1 vote
0 answers
128 views

VFD or soft start to minimize power consumption on starting a motor?

I want to use the smallest generator possible to run a standard three-phase AC well pump. According to this website and others, it is advisable to use a generator capable of 3x the running kVA if the ...
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1 vote
0 answers
47 views

Building a custom indirect actuator, any thoughts?

I’m trying to create a custom indirect actuator, that is controlled by a microcontroller, for a custom robotics project. I have selected motor and gears (according to Fd = W = T2*pi) so that the ...
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1 vote
0 answers
42 views

Motor part winding start

I have a BITZER compressor type 4GE-23Y-40P, with a part winding start option Nennspannung = nominal voltage = 380-420 Frequ = frequency = 50 Betr. strom = maximal operating current = 43.9 ...
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1 vote
1 answer
207 views

Why are the synchronous reluctance motors not self-starting?

I have been studying synchronous reluctance motor since a month. I am curious to know why is this motor not self starting? If used with an inverter, this motor can be made self-starting. Or by adding ...
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1 vote
0 answers
56 views

How much torque is needed to mix melted marshmallow with rice krispie?

I am designing a robot to make rice krispie treats! More specifically, I want to use a fork to mix the melted marshmallow with rice krispie. I am currently specing out the motor, and since marshmallow+...
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1 vote
1 answer
160 views

Torque Required for a stepper motor to rotate a socket wrench ratchet around an axis point

I'm trying to build a kinetic machine that rotates socket ratchet tools (e.g. https://en.wikipedia.org/wiki/Socket_wrench) to make a bunch of ratchet 'clicking' sounds for an art project. I'm trying ...
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1 vote
0 answers
13 views

DIY device to repeatedly depress and release gas pedal on a vehicle

The pedal needs to be depressed about 1/2 to 1 inch, once every three minutes. I believe the best way to do this will be with a rotating arm of length 2 to 2 1/2 inches that has rollers on each end, ...
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1 vote
0 answers
23 views

Secure loads to gearbox shafts

I have a sculpture that is designed to rotate over 3 axes at max. 30RPM and is mounted on an aluminium disc. My plan is to use 3 of these geared steppers and secure the sculpture to the Z-axis shaft, ...
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1 vote
0 answers
36 views

BLDC Motor underwater ; weird behaviour

I recently was riding my e-bike (with a bldc hub motor) and decided to cool the motor (it -the stator- was approx 100-150 celcius I think) in the river. The controller is on the top of the bike and ...
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1 vote
0 answers
133 views

Given a BLDC motor with one shaft, where should I attach my encoder?

I have recently purchased an ODrive servo controller made for hobby BLDC motors. Since I had a BLDC motor at home, I did not purchase a dual shaft motor when I got the ODrive. My question is if I ...
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1 vote
0 answers
125 views

Wobbling DC motor head

I have used 250 watt DC motor, for DIY electric potters wheel. Motor rated with RPM 3300 and geared reduction to 330 RPM. The issue I am facing is wobbling of the motor head. This issue is with the ...
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1 vote
0 answers
23 views

Axis connection types

Complete hobbyist here. I have two questions I have a problem figuring out. I have hard time finding information about axis and types of connections they have. For example take this worm gear reducer: ...
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1 vote
0 answers
17 views

how do you calculate viscocity from torque arm load cell measurements?

I have a piece of company developed equipment that uses a pot mounted on a rotating base plate with a 0.15m torque arm and load cell, a mixing paddle is used to stir the mixture while the controller ...
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1 vote
3 answers
286 views

How to calculate the torque created by a rotating motor?

I have watched this video where the speaker explained how the vertical spin of a quadcopter is stabilized, and how it could be unstabilized to make the drone rotate. Here is a screenshot of the video,...
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1 vote
0 answers
116 views

Is it possible to have the load cell signal as feedback to the servo drive of the servo motor?

In my project, I have to control the linear motion in one of the two modes. It will be either in position control or load control. for the displacement control, The servo motor takes the quadrature ...
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1 vote
0 answers
97 views

The optical encoder resolution

The optical encoder has a code wheel with a single track of slots and two photodetectors. The photodetectors are positioned so that they produce signals with a 90 degree phase difference. I want to ...
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