# Questions tagged [mechanical-engineering]

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

4,370 questions
Filter by
Sorted by
Tagged with
7 views

### I was solving fluctuating load problems and the word "static" confused me

Here's a snippet of the question that was asked a couple of years ago in university exam: A cantilever beam made of cold rolled steel for which ultimate tensile strength =540 MPa and Yield tensile ...
17 views

### Can I use logarithmic decrement to get damping ratio when given data is acceleration?

Since I was going to get the damping ratio from time domain, the first thought was using logarithmic decrement method. But I'm not sure if I can use it when the given data is acceleration-time. Can I ...
• 1
11 views

### Flow in vent of a pipe

I have a horizontal pipe of diameter 2000mm (uniform cross section), the pressure of gas flowing in the pipe is 1.2bar and the flow velocity is 15m/sec. there is a 100mm diameter vertical vent ...
13 views

### Confusion in deriving von Karman equation for strip rolling

In the derivation for von Karman equation for metal strip rolling, an infinitesimal element is chosen as shown in the picture above. The equilibrium equation for the element is as follows: Upon ...
16 views

### Anything about Linear Modules? [closed]

We produce the linear modules and we can talk any about this here. does anybody need this product?
• 1
55 views

### How did mechanical punched tape readers work?

How can a purely mechanical mechanism distinguish between holes and non-holes in the tape, without deforming/ripping the paper, and then effect a larger difference depending on the sensed bit with ...
• 111
23 views

### Some questions at interpreting FRF from vibration test

Currently going through impact hammer test of cantilever beam(200mmx20mmx2mm) which is made of particulate composite(Epoxy/PZT/CB). Hammer sensitivity is 2.25mV/N and accelerometer sensitivity is ...
• 1
35 views

### How to calculate the material and thickness I need for a certain force on it?

I am trying to figure out how to design how thick a material has to be so that the bar shown in picture 1 stays intact when a user is running on it. Background: The project is a treadmill and the user ...
1 vote
102 views
+50

### Mechanical mechanism to store and update state of fixed state transition table

Given a state transition table like this: 1->3 2->1 3->4 4->2 (If the system is in state 1, next change to state 3 etc.) In my actual use case there ...
• 111
1 vote
20 views

### If building a DIY screw jack, would it be beneficial to add a gimbal to the jack nut, and/or to the screw attachment?

The screw jack will be used twice daily. It will be made out of M24 8.8 grade threaded rod and nut. The nut will travel 300mm, to raise a weight of 50kg by 800m, via a pivoting lever arm. The parts ...
1 vote
58 views

### How do lifts remain steady as passengers embark/disembark?

I'm referring to the kind of lift that takes people up and down floors. I notice lifts are very stable as people get on or off. Since the lift is presumably stationary because the tension in the cords ...
• 145
5 views

### Help Needed: Looking for Sample Phase Change Material (PCM) Calculations

I am working on implementing a Phase Change Material (PCM) system for a cold storage facility. While I'm familiar with traditional refrigeration systems, I'm relatively new to PCM technology and would ...
1 vote
23 views

### Parameters to characterize heat dispersion

I'm working in a team to model some production machinery in a factory. They ask me to find a way to describe and quantify the heat loss to be able to make an initial and approximate comparison between ...
• 11
11 views

### Calibrating the commercial bar-type load cell for measuring weight at tilt

The commercial hobbyist bar-type load cell you buy at ebay for about 3 dollars or so has 4 strain gauges (two at the top and two at the bottom) for measuring weight that is perpendicular to the load ...
16 views

### Why Volumetric efficiency is not considered as a performance parameter in case of 2 stroke engines

This mentioned in almost all standard books that for two stroke we use scavenging efficiency and trapping efficiency, but does not mention the reason, why volumetric efficiency is not used.
21 views

### Dictionary of Mechanical Engineering Part Feature Vocabulary

Anyone know of a good Dictionary/ Compendium of the technical names of Mechanical Engineering part features? EG. Standoff, Draft Angle, Truss, Axle Bore, Pivot, Etc. I'm an inventor and I'm designing ...
84 views

### Where do engineers find the manufacturing processes of objects?

I'm an engineering student and we have a reverse engineering project going on. We need to disassemble a simple object and understand how it is made: which processes are used, why, how much it costs... ...
68 views

### Would placing sand bags on top of a car's strut housing reduce the jarring impact felt when the car hits a pothole?

I live in an urban area where many of the streets have pot holes and some of these streets have some very large and deep potholes. I have been wondering lately if it would be worth the effort to try ...
• 281
39 views

### Tesla's resonator -- would that work?

Note: One bio, by an engineer and therefore I think taking a more sober approach (no "woo" science) is by Carlson (Tesla: The Inventor of the Electrical Age) describes Tesla turning on his ...
• 119
43 views

### What is the hole tolerance in hand tap guide?

What is the tolerance for through hole to match the UNC 1/4-20 tap ⌀ 6mm? (tap shaft diameter ⌀ = 6mm) I want to make the diameter of the hole such that the tap stands in the hole and doesn't fall ...
• 103
32 views

### Example of Extremely Tiny Amount of Horsepower

I just took an exam and messed up the horsepower calculation acting on a pinion and got 0.059 hp (correct is 1.67 I believe). I should be fine grade wise I am simply curious about an example of ...
33 views

### Do tensile and compressive stresses create moments?

Below are 3 examples I designed. My question is about the tensile and compressive stresses that occur in 3 examples under the influence of a horizontal force F=100N (earthquake force). I ask my ...
1 vote
44 views

### Mechanical linkage to tilt a monitor around an edge

I am not an mechanical engineer, but would need a construction to attach a monitor to a wall and be able to tilt the monitor around the lower edge of the frame. I want to achieve, that the rotating ...
• 11
12 views

### Addressing Variations in Stress Levels for Accurate Fatigue Analysis of Crankshafts

In analyzing the fatigue resistance of a crankshaft, how should we account for the variation in stress levels throughout its 360-degree revolution? Given that the crankshaft is subjected to different ...
21 views

### How to create mechanical arms with joints and resistance

I want to create a mechanical arm with several sections connected by joints. Think exoskeleton kind of. This arm will have a handle at one end and the user holds onto this handle with their hand. Now ...
16 views

### Calculating the torque of multiple nuts

I need to press hockey puck scr to a certain force, so I must hold it between two plates and by bolting plates apply that specific force to the hockey puck. I am using the torque wrench and 8 bolts, ...
17 views

### Can this new AC motor/generator design work?

I'm currently in the works of developing a vertically suspended flywheel, and I'm trying to figure out the best method to convert rotational energy to electrical energy and vice versa. I don't want to ...
• 105
83 views

### Would you wear out the/a clutch in a modern automatic transmission if you drove 5000 km at 1 km/hr?

If you drive a (modern or old) manual transmission car for 5000 km deliberately at 1 km/hr, you will burn through the clutch (long before you reach your destination). The idea is this. If you attempt ...
• 441
32 views

### Connecting rod sizing

Good evening, it is possible to calculate the dimensions of a slow connecting rod with an H section, having a force applied on the cylinder head of 634kN, a speed of 300 rpm, the length of the ...
14 views

### How does an impact driver hammer and spring mechanism cam backwards when loosening fastenings?

For an electric impact driver / impact wrench, how does the hammer mechanism cam backwards and forwards? In reverse (loosening fastenings), the spring twisting would cause spring extension, not ...
50 views

### Static Equilibrium of Rigid Bodies

When we talk about the idea of static equilibrium in engineering mechanics we consider the idealized case of a body which is a rigid body, meaning it cannot deform. Then we solve for the 3 equilibrium ...
• 1
82 views

### Did anyone ever make training wheels for the original Segway personal transporter device?

I am curious to know if Segway, or any other company, has ever made front and rear training wheels for the original version of the Segway personal transporter device. To help illustrate what I mean by ...
• 281
1 vote
62 views

### How to calculate the torque disturbance of an unbalanced flywheel?

I would like to understand how an unbalance of a flywheel affects the dynamics of a simplified mechanical model. Assuming that the mechaincal dynamics can be modeled as (neclecting inertia of the ...
• 11
15 views

### High temperature in seal oil vacuum pump (not in the bearing), steam power plant. Why the seal oil vacuum pump suddenly increased in temperature?

Seal oil vacuum pump in steam power plant, suddenly have temperature increased, it's in the pump's body, not in the bearing. Why is that happen? I noticed that temperature of main seal oil tank in ...
18 views

### What does the resonance frequency mean in inertia matching

Like Kollmorgen shows in this PDF how you can calculate the resonance frequency of a motor coupled to a load. But with what can I Compare this frequency? It is clear that a higher resonance frequency ...
• 1
1 vote
20 views

### -AN Fitting Compatibility

I have a -6 AN fitting on the end of a hose. I am not familiar with AN fittings and I don't understand how to interpret the table at the bottom of the Wikipedia page on this subject. Does this table ...
1 vote
48 views

### Which aluminum alloy is used in cheap commercial load cells?

I am planning to simulate a load cell in CAD and was wondering which aluminum alloy are cheap commercial load cells made of? I noticed there is no huge difference between the common aluminum alloys in ...
36 views

### Free body diagram problem: Linkage w/ magnets and friction hinge

I am a bit stumped on a IRL problem, which i simplified in the diagram below: There are left and right beams (gray) linked together by a friction hinge. The bottom beam (black) is connected to the ...
• 21
42 views

### How to make Peaucellier–Lipkin linkage work?

I tried in math.stackexchange.com and they send me here. First: Don't crucify me for not "doing math", or asking a dumb question. School was a long time ago, and lose what you don't use. My ...
1 vote
37 views

### Elongation before plastic deformation

As far as I understand elongation is the lengthening of a metal in % of it's initial length right before it breaks. But what is in practice more interesting (for some aspects of my bike use case) is ...
• 23
17 views

### I have a question about INISTATE Code (Analyzing a curved plate)

I'm studying welding-induced residual stresses for curved steel plates. So, I need to use the INISTATE code taking initial stresses. This is the picture that I want to analyze. I divided a curved ...
34 views

### How does the thrust rating of a push rod/linear actuator (I've seen it in both kg and N) relate to the amount of weight it can move?

I'm working on a custom RC project, and I'm needing to move a lever with a "weight" of 5 lbs. 5 lbs is required to actuate the lever, and I need to push it 5 mm. Gravity does not affect the ...
34 views

### How can I modulate rotation speed of a wind powered device?

I am building a kinetic sculpture. In part of the sculpture I have an axle in a sealed bearing. At the end of the axle are three fan blades that catch the wind and rotate the axle. I can configure the ...
46 views

### Mechanical fasteners for HDPE pipe and sheet?

I need to fasten pieces of HDPE together but I’ve heard gluing HDPE is difficult. I've bought sheets and pipes to make a feeder for a tortoise. I will be using the sheets for covers for the pipes. The ...
51 views

### How accurate is axisymmetric beam theory for modeling plate bending?

I often have to do a quick estimate of circular plate deflection and max stress under simple loading scenarios – uniform distributed pressure, central point load, line load, distributed annular ...
• 781
27 views

### Book claims one can derive USCS mass unit "slug" from temperature equation shown in screen shots below

In the screenshots below, the author claims that one can derive the mass unit "slug" by somehow using the equation shown in the first picture. I understand how could derive a slug if you ...
203 views

### What are the benefits of using a spring as a drive screw in this electronic deadbolt?

The Schlage FBE365 electronic deadbolt uses a DC motor attached to a helical screw to raise and lower the C-shaped piece shown. The way the rest of the mechanism works is not important for this ...
• 67
37 views

### Identify pairs of points of constant distance between them, placed on two moving (rotating) rectangles

Let there be two squares (or rectangles, but say its squares for simplicity). These squares are attached to an axis (bellow, marked red) around which they can rotate. For simplicity, let's say they ...