# 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.

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### Calculating reaction force of pipe elbow

I am currently studying for the mechanical FE exam. There is a problem in the fluid dynamics section that is not making sense to me. Problem statement: I solved it using momentum balance and I got 50....
0 votes
1 answer
39 views

### Need to find beam deflection of a steel tube

So i have a square tube of 40mm, 3mm wall thickness with a length of 1 meter. Both ends are fixed 25mm inwards. Load is 3kg centerpoint. Steel is SJ235. I need to know the deflection of this beam. ...
0 votes
1 answer
157 views

### Pressing and strapping of a step-wise object

I am not a mechanical engineer and I would appreciate a bit of help on the following matter. Namely, suppose there is a step-wise object with shape and dimensions provided in Fig. (a). In fact, the ...
0 votes
1 answer
57 views

### Principle of RF MEMS switches

I am studying mechanical engineering at university and am trying to design an RF MEMS switch. In "RF MEMS Switch Li-Feng Wang, Qing-An Huang, and Lei Han" says "When an adequate voltage ...
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0 votes
1 answer
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### How does the mechanics of left-handed scissors differ from right-handed/standard scissors?

So I've read that my right hand with a left-handed scissor "pushes the blades apart" (same with my left hand with right-handed/standard scissors), but I couldn't find out why this happens or ...
2 votes
0 answers
19 views

### What is Drift flux in two phase flow (Fluid Mechanics)?

I recently started learning about two phase flows. While studying I came across relative velocity, drift velocity and drift flux. I understand the first two terms, but I don't understand the concept ...
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0 answers
29 views

### Electromechanical connection for lamp

I need help with a project and would appreciate any advice or recommendations you can provide. I'll do my best to explain my concept and the issue I'm facing. Concept: I have a pad with a heavy ...
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0 votes
1 answer
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### Showing where the axis of a spindle is pointing

I have a spindle which is about 200 mm in diameter. I want to indicate where the axis of the spindle in pointing. I can attach any laser pointer etc. on the circumference of the spindle. Is there any ...
1 vote
3 answers
268 views

### Calculating velocity of two different weight in a system with spring

I get a question like this. But what if the angle is given as theta=60° and I'm required to find the velocity of each weight. I tried the work energy equation but it doesn't seem to work since there ...
0 votes
0 answers
30 views

### Coupling two motors to get more Power

Can I couple two motors on the same shaft to get more power, in order words if I couple two 5HP motors on the same shaft will I get more then 5HP at the shaft. If yes what calculation will I have to ...
1 vote
1 answer
84 views

### Why is FEA used for structural analysis?

Is there a reason for using FEA to perform structural analysis over for example Finite volume method for example?
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1 answer
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### CFD numerical methods (FEA, FVM, FDM,…)

I just read the answer from this question and have a question please: What I read: Computational Fluid Dynamics (CFD) refers to the use of the numerical techniques to solve fluid dynamical problems. ...
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1 vote
0 answers
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### Forces on a catenary cable span

This relates to an unusual action on a catenary cable span and is not covered by the many available calculators or standard formulas. I'll add a diagram 'tomorrow' if attention warrants. (0400 now - ...
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1 answer
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### Button activation on turning gear mechanism

Description of the mechanism: By turning a manual crank the mechanism activates a microswitch to activate an electronic circuit. The rotation is continuous and the microswitch must remain activated ...
0 votes
2 answers
51 views

### Finding zero-force members of truss system

My instructor gave the below example for identifying zero force members in truss. The members marked with the green zeros are the zero-force members, according to his solutions. I cannot understand ...
0 votes
0 answers
32 views

### Understanding mesh for a cylinder

I came across this video on YouTube, and would like to know more about the mesh, such as the internal structure. Is there a reason to do it that way? Am i correct in saying there is an o-grid around ...
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1 vote
0 answers
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### What is the fastest way to move a 720 ton statue for a distance of 500 km from Cairo to Luxor with modern technology?

The ancient egyptians could do it but we don't know how long it took them. What would be the fastest way to do it with modern technology? How long would it take? https://en.wikipedia.org/wiki/...
0 votes
0 answers
35 views

### How to attach plates (my design) to the stator core of the machine more efficiently and precisely?

I am working on an electrical engineering project. However, I have come across a specific mechanical engineering problem. I have attached an image to describe what I want to do. I have primarily a ...
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0 answers
48 views

### When to use MPC Contact formulation in Ansys?

I was suggested to use MPC while analysing with beam elements. It's for an analysis of a table to be used in harsh shock conditions.
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0 answers
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### Suggestions for estimating Heat Load (watts) in an evaporator (antifreeze - hot fluid, R744 - cold fluid)

I am working on simulating an evaporator for an R744 refrigeration cycle. Here, I have inlet conditions of R744 with low pressure (around 30 bar) and low temperature(-8°C) and that of antifreeze (35% ...
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0 answers
21 views

### Attaching a flat, round, large diameter cover plate to a hollow casting

A 200mm diameter, 10mm thick bearing plate needs to be attached to a hole in a 10-15mm thick walled, hollow cast iron (or more likely cast steel) casting. The plate needs to sit flush to the surface ...
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0 answers
37 views

### What is the general approach to having three hands on a clock all rotate on the same axis but at different speeds? [duplicate]

I want to build an art piece which would have three disks rotating all about the same axis at different speeds. Mechanically this would function just like a clock with hour, minute and second hands (...
1 vote
2 answers
44 views

### How does an expansion valve cool fluid?

How does fluid loose temperature after leaving an expansion valve in a refrigeration cycle? Where does this heat go?
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0 answers
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### Need for diaphragm carburetors in small internal combustion engines that run on gasoline

I have seen that hobby internal combustion engines that run on gasoline always use diaphragm carburetors instead of the very simple carburation system used by glow engines that generally consist only ...
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0 answers
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### Determine moment and shear stress door

Determine shear stress and moment of bolt: Internal Height of Door = 198.2 cm Internal Width of Door = 89.9 cm Thickness Door = 3.9 cm Weight Door = 45.76 kg or448.9 N Elasticity = 9.8 GPa or N/mm2 ...
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0 answers
27 views

### Making ellipsoids fall with the longest axis down

Lets say I have a box full of ellipsoids. They vary in size and shape but are smaller than marbles. I want these ellipsoids to fall so that the longest axis points straight down. Preferably, I also ...
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1 answer
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### Trying to detach a detachable handle on a meat grinder

I'm trying to detach the handle from my meat grinder. I'm not sure what this kind of lock is called but it had a crescent/half moon shape that locks against the grinding (clockwise) motion. In order ...
0 votes
2 answers
37 views

### Looking for bolt with press nut

I'm looking for a bolt without a thread that I can attach to an object using a kind of press nut. Whats the name of these kind of bolts and nuts? Can't find any information about it?
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1 vote
0 answers
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### Please see image and calculate for combined stress and deformation

This image is from an assignment I am struggling with this question. help would be much appreciated The cross section of the I-beams truss structure is 0.0031771m². The forces from left to right are, ...
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0 answers
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### How can I determine the best thicknesses of a circular plate to achieve minimum weight and high strength?

I want to design a circular plate made from iron ductile material, So I want to determine the best thicknesses of the profile (t1,t2,t3,...etc) as shown in the image tyo achieve the best plate weight ...
0 votes
1 answer
29 views

### What would be the consequence of operating a mechanical transmission at low temperatures

Is there any risk of mechanical failure or other detriments resulting from running a mechanical transmission at low temperatures? The transmission in question is connected to the vehicle's coolant ...
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### What is the recommended Nylon washer thickness, OD and ID for M2.5 screws?

I am using two different M2.5 screws. One has head of diameter 4.5mm and the other has a head diameter of 4.75mm. If I want to use Nylon washer to distribute the load evenly, what is the recommended ...
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### ASTM B209 does not list Aluminium Alloy 1070

This is my first post. We manufacture products using various grades or alloys of Aluminium sheet, one of our common alloys is 1070. In referencing the ASTM B209/209M-21a standard I do not see 1070 ...
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2 answers
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### What is the difference between maximum principal strain and maximum in-plane principal strain?

For the purpose of answering/explaining this, it does not need to be restricted to strains (i.e., it can be stresses too). I am mainly trying to understand when to use which one (i.e., if I am ...
0 votes
1 answer
52 views

### How to balance an irregular shape on a motor shaft?

I have an irregular shaped object about 100g in weight and 3x3x3 cm in size that I'd like to mount on a shaft (eg of a small motor) and spin. The trick is, I'd like it to be pretty close to perfectly ...
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0 answers
34 views

### Are there pressure vessels with hand inserts?

I'd like to work with some bike-tire parts while at moderate pressure (60 psi), so I'm hoping to use a pressure vessel, but it has to be transparent and have inserts so I can use my hands to ...
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0 answers
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### Can the volume of fluid flow affect a strain gauge's measurement accuracy?

I have two machines for testing solenoids, one new and one old. When a bypass is connected to both hoses (the input hose is connected to the output hose), I get ~1:1 for the input output pressure; the ...
0 votes
1 answer
31 views

### Deformation Due to Material Removal and Residual Stress

Suppose I have a piece of metal (of arbitrary geometry) with some residual stress profile. I then remove a chunk of the metal and the piece of metal deforms (due to the residual stress). For ...
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### Checking if a Residual Stress Field Achieves Mechanical Equilibrium

Suppose I told you the Cauchy Stress Tensor at every point inside a chunk of metal. And, yes, I know this means that I would need to tell you about an infinite number of points - let's ignore that ...
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2 answers
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### Connect two motors to different planes and rotate them on the same center point

I am trying to design a kinetic art sculpture. I want to rotate two independent planes at the same center point and control both their speed and direction independently. So I've found that having two ...
0 votes
1 answer
50 views

### One way bearings

I want to use one way bearings for a project, but there are some things I just can't figure out about them. So I know that a one way bearing restricts rotation of an axle in one way and allows ...
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0 answers
33 views

### How to add compressor curve in Aspen HYSYS for a centrifugal compressor with IGV and only one efficiecy 65% is given in data sheet at 400rpm

I am trying to check the adequacy of existing centrifugal compressors in a gas train. The adequacy check is required due to a new tie-in in an existing gas train inlet, from a new source of "...
0 votes
1 answer
36 views

### In a lead screw mechanism with a fixed travelling nut, will the screw and its driving mechanism move instead?

https://www.youtube.com/shorts/tUkkOStjz8o Imagine this but upside down. Since the platform bolted to the travelling nuts will be pressed against the ground and will have nowhere to go, I reckon the ...
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0 answers
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### Impact on high frequency radial forces on ball bearings

Dear Stackexchange forum, Do high frequency radial forces (e.g. 6kHz) do significantly increase wear and reduce the life span of ball bearings? I am looking for an expert in ball bearing research ...
-1 votes
2 answers
68 views

### Will a lid hovering above bursting air bubbles catch smog particles

The bubble bursting phenomenon goes like the above describes: At 1, the air bubble is under water. At 2, the bubble emerges above the surface, with a thin film of water rising to keep it from bursting....
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1 answer
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### Continuous swinging machine

I'm making art piece that is hanging from roof and I would like to have it in continuous swinging motion. What kind of mechanism could be used in this case? info about the art piece about 16kg shape ...
0 votes
2 answers
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### Is there a way to add a DIY knock sensor to an engine?

I have a Rotax 914, a type of aircraft engine which is basically a 1980s turbocharged carbureted 4-cylinder boxer. There is no knock sensor, but considering the absolute devastation that detonation ...
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### Metal casting simulation and the solidification analysis

Casting process analysis Mold filling affects the quality of a casting. The fluid flow phenomena are closely related to the casting quality and surface finish. The dimensional accuracy of a casting ...
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1 answer
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### What is the name for a design element which includes trusses within a member?

I cannot think of what to call this design technique, where a truss-like structure is used within a member to provide strength and rigidity with minimized weight. I’ve included a picture which ...
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### A mechanism that modifies the sine wave so it is flattened at its peaks

Piston displacement as a function of time produces a sine wave. I need to modify the motion so the time the piston spends at both the bottom of the stroke and the top of the stroke are extended. The ...