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Questions within the problem domain of mechanical engineering. Mechanical Engineering can be a broad field; consider choosing more specific tags if they apply.

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1answer
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Punching of soft materials

The process of punching a soft material uses a hallow punch with beveled and sharpened edges that is driven into the material. The backing material is usually a soft metal or wood. I am working on ...
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0answers
13 views

Why increasing the coefficient of friction results in evenly distributed load in rolling machines?

I'm designing a rolling machine for reduction of steel ingots of $5 mm$ to $1.96 mm$ thick. I can convince myself using equations why increasing the coefficient of friction (in case of lubrication ...
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0answers
28 views

how to choose a good motor based on application

I'm new in motor industries. I have a project which is to spin a platform disc which is the weight is 1kg and the maximum speed I need is 10000 rpm. Could you suggest what kinds of a motor is good for ...
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1answer
23 views

Calculate the torque needed to turn a rod it's own axis

If a rod is turned around it's own axis, force/torque is needed. Let's assume the rod it self has a diameter $d$, a length $l$, the mass $m$ and should be turned by a motor on one side. The other ...
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0answers
8 views

Why the internal forces in section exist in its plane and equal to load applied

I am new to mechanics of materials.I am learning shearing stress from beer and Johnston mechanics of materials.In this book,when they have applied two opposite and equal transverse loads P and P' in a ...
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0answers
15 views

What are the challenges in building a 'sports car' frame and body?

Clearly if it were easy to produce attractive looking cars for cheap, there would be a lot more 'modern' and good looking cars on the road. While beauty certainly is in the eye of the beholder in ...
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0answers
9 views

Modeling Rotation and Translation of surface B.C. in Abaqus

I am trying to model a test which has grips that can translate in X and Y directions, as well as rotate. I have been trying to model this using constraints and a reference point but have not been able ...
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2answers
29 views

Microspeaker enclosure design for headphones

I want to embark on an acoustic project of designing an enclosure for some 40mm microspeakers, identical to ones found in a typical on-ear headphone solution. Are microspeaker enclosures treated in ...
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0answers
26 views

How do I figure out how much force a screw is applying to a wedge?

I am looking at Mitee-bite Uniforce clamps, model no.60750. How would i calculate the force applied by the wedge. So if the center bolt was tightened to 50 inch lbs. What would be the amount of ...
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0answers
34 views

Science of Lock Picking: bump hammer - gimmick or scientifically superior? [on hold]

Premise In the lockpicking community, there are mixed opinions about bump hammers. Some say it is merely a gimmick, while others boast of its superior performance. Where there are product reviews, ...
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1answer
50 views

Why all watches hands are stacked in that specific order ? Can it be changed?

It's just a matter of curiosity, but I find hard to justify why every single watch keep the hour hand below the minute one; from a user perspective, it seems a poorly design decision for those times ...
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1answer
31 views

What is the type of hinge used in fold-down car tv's?

I am trying to find out what type of hinge or mechanism is used in fold down car TV's. I need to buy one for a project I'm working on but dont know the name. See picture above.
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0answers
30 views

Finding equilibrium positions (All)

I have tried to calculate the Kinetic and Potential energy of the given mechanism. I would be glad if somebody could have a look and confirm if it's correct. One of the equilibrium positions would ...
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0answers
38 views

Finding constraint condition + Kinetic and Potential Energy

I am trying to find the Kinetic and Potential energy of the slider-crank mechanism shown in the fig. I am not sure what I have calculated is correct or not. I would be glad if somebody could confirm ...
2
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0answers
34 views

4 Gears in a Circular Pattern - Calculating the Proper Distances for Meshing

I have recently been working on a gearbox for a robot. I have this pattern of 4 gears with each gear connected to its 2 neighbors. It looks like this: You will probably notice something though. ...
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1answer
57 views

Analytic expressions of the kinetic and potential energy [closed]

A homogeneous rigid circular disc (radius R, mass ms, center point S) rolls without a slip on a plain with a small angle of inclination alpha against the horizontal. A point mass MG is fixed on the ...
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0answers
17 views

geometry and meshing [closed]

I would be grateful if you could explain me the process of the geometry and the mesh of the following system: A cubic cell of which edges having full cylindrical forms (the diameter of the cell is ...
1
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1answer
29 views

How can we calculate torque required to rotate the wheel (mass unknown)

Is it possible to calculate torque required to rotate wheel but weight of wheel is unknown?
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0answers
51 views

Eigen-Modes for a homogenous, non-conservative mechanical system

$$ M\,\ddot{y}+D\,\dot{y}+K\,y=0\\ y=\begin{bmatrix} y_1&y_2&\cdots&y_f \end{bmatrix}^\top\\ M=M^\top>0,\quad D=D^\top,\quad K=K^\top\geq0 $$ Equations show a homogeneous non-...
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2answers
32 views

Method for permanent adjustment of pitch and roll of a mounting plate

I have a 2D lidar mounted to a plate on a robot. I am looking for a method to adjust the pitch and roll of the plate so the plane of the laser is parallel to the ground. Currently, I am using thin ...
1
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1answer
28 views

Shear force and bending diagram un-uniformly distributed load

I already got great help on this topic, but I'd like to make sure that I get it. For example, take a beam of length 6 meters, left side fixed support and right side rolled support. There is a load of ...
2
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4answers
302 views

Looking for the name of a part

I'm looking for a name of a part. It looks like a cable inside another cable. The idea is that you can just pull on the inside cable and get the force at the other end. You can just attach the outside ...
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2answers
42 views

Thermoelectric Module Not Working Properly!

I have a TEC-12706 thermoelectric peltier module. I am making a mini refrigerator (simple box refrigerator). I'm using this peltier and heatsink of equal size as compared with the peltier. I have ...
1
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1answer
38 views

Calculating force exerted on plate by link

I am currently involved with a project using a mechanism similar to that seen in 'table tilters' and we are struggling to work out how to begin resolving the forces. The image shows the state we are ...
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2answers
39 views

Practical rugged method for elevating water 7 feet high? [on hold]

At a very low-tech, rustic forest camp, I've built a 'water tower' connected to a gravity-fed water filter to provide something like a clean water faucet. It's basically a 5 gallon bucket on top of a ~...
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0answers
37 views

Build and visualize Pitch, Roll and Yaw from 9dof data offline

I am trying to build pitch, roll and yaw from sensor readings of a 9 degree of freedom sensing device. The data look like that (in a .csv file): ...
2
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1answer
27 views

Deflection of a stack of disks under applied force/pressure

I'm trying to calculate the deflection of a stack of metallic disks, when subjected to a force. In the case of the figure below, representing a valve for a shock absorber, the force is due to a ...
0
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2answers
41 views

what thickness steel sheet for a motorcycle turntable

i have a 300kg motorcycle with a 1630mm wheelbase. I have a lazy susan 1000kg bearing, which will be centrally mounted on the steel plate. what is the minimum thickness steel plate at 350mm wide i ...
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0answers
28 views

Manufacturing line Efficency

This is my first post, if there is a different section this should be posted in please advise and I will move it. Here's my engineering problem, So I've recently run into a problem at work, and it ...
2
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0answers
28 views

How to prevent movement in this 3 DOF setup?

I have a 3DOF platform that I'm trying to make more stable. It's difficult to explain in words what the issue is so I've added a GIF below. Any ideas of how I can get rid of this wobble? The DOF arm ...
2
votes
1answer
41 views

Rigid circular disc equation of motion

I am working on an assignment and I have a doubt in a step in my problem. Could someone please help me understand it? Question and its solution is: . My doubt is in the part which is underlined. How ...
0
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1answer
34 views

Designing a horizontal pressure vessel

The question reads Design a horizontal pressure vessel with hemispherical head supported by saddle support and fitted with 2 nozzles welded to the head. It's used for storing and delivering fuel ...
2
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1answer
48 views

What material is it? [closed]

I'm designing a coordinate measuring machine for my FYP. I need to know what is that black zigzag flexible cover usually made of. Is that leather, rubber or some other material? And how is it ...
2
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1answer
22 views

Shear strength polymers

I was looking for some shear strength properties of common polymers/plastics.... I have not found any usefull information yet. I know polymers aren't that linear elastic, but I expected to find some ...
3
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1answer
57 views

How to couple/connect shaft to disk?

I'm new to part design/mechanical engineering and I have the following question. Blue: steel shaft, 5/8" diameter, connected to a motor Green: aluminum disk, 10" diameter, 1/2" thick, 3" hole Goal: ...
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2answers
78 views

Finding out torque in a viscosimeter

I am solving problems through Fox and McDonald.Here is the problem I tried by finding out the torque due to viscous forces which is $$\tau_1=\mu(2\pi Rh)\frac{R\omega}{a}$$ and the torque due to ...
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1answer
34 views

What does the torque curve of an engine mean?

I have been trying to understand the torque curve and power curve of an engine. From what I have read and understood I know that the torque curve and power curve is has a peak at a particular RPMs(RPM ...
1
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1answer
38 views

Linear actuator on a scissor lifting table

I am designing a scissor lifting table and I have an issue with the linear actuator. This table should be lifting 100 kg. I studied the problem in two ways : a static study and a power study. My ...
1
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1answer
24 views

Two intersecting prisms

Case 1 The development of Case 1 of this problem in which the axes of the prisms intersect at right angles, is shown in Diagram 1. Note that inter-edge lines are required for the development of both ...
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0answers
33 views

press fit ball joint

I enjoy creating mechanical designs but I am not a trained mechanical engineer. I have a technical issue with a joint design that needs to be permanently retained using a press (snap) fit. Any idea ...
0
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1answer
25 views

How can I calculate headphone driver excursion?

I'm a headphone enthusiast, and once I tried to open up my headphones to see how much they move when I play my music. However, I was really surprised to see that the sounds that I could "feel" ...
2
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0answers
31 views

How to join two beams rigidly?

Hi I am making a beam model using Abaqus. There are two beams created. I wanted to join two beams rigidly in the connection to transfer moments between beams. However, I do not know what connector or ...
2
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2answers
52 views

What is this V-shaped strut on the landing gear for?

On this video from Captain Joe, you can see that the landing gear of the airplane has got some sort of v-shaped strut connecting the two moving parts. I think that I saw the same thing on some vespas ...
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2answers
17 views

Dimensioning Confusion

Can someone help me with the dimensioning convention used here?Usually the coordinates are given as cartesion X,Y,but I am unable to understand this convention. Also each individual hole size is not ...
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1answer
32 views

Cruise Control Project on Toy Car

I finished taking my control theory course, and I want to build an RC car that has cruise control. So I started off with the force analysis, and I got external forces that are constant. For example if ...
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0answers
51 views

Why do cornering vehicles need yaw motion to turn when facts prove otherwise?

Considering what we know about rotation, laws of motion and using a few examples below, is yaw motion even needed for the cornering vehicle to turn? Vehicle dynamics claims the need for yaw motion ...
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0answers
35 views

Using an unstable controller that gives a stable closed loop performance

I have system with controller (a state-space system with 0 reference input; this is the equivalent transfer function representation) $$\frac{9.1 s^2 + 73.5 s + 125}{s^2 + 17 s - 30}$$ which is ...
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1answer
11 views

Calculating NPSHa for a pump

NPSHa formula - h(sp) +/- h(s) - h(f) - h(vp) h(sp)- static pressure head (absolute) applied to the fluid h(s)- elevation difference between fluid level in reservoir to pump inlet h(f) - friction ...
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1answer
27 views

Using place command in MATLAB using different state representation

I had a transfer function $$\frac{10s+20}{s^3+10s^2+24s}$$ and I found the state space representation of the above using MATLAB. Using $place(A,B,[poles])$, I found a gain matrix K that corresponds ...
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2answers
35 views

How does bell housing guarantee the concentricity of the shafts?

I'm talking about IEC motors-gearbox alignement. Here are an example: I found the drawing in cross hydraulic website, so it's quite reliable. What i don't understand, is, how this design makes sure ...