# All Questions

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20 views

### Is there a loss in light transmission when using acrylic lens, instead of glass, for collimating a led light beam?

I've got a led headlight for illuminating a small spot region at 30cms distance from my head. I've let it fall and the glass lens chipped. So I unscrewed the lens and got a piece of acrylic rod which ...
15 views

### How to calculate the torque for motors for a Core XY movment?

I am trying to design a simple setup that follows the core XY movement shown: I have been researching the statics behind this movement in order to calculate the minimum torque for the motor so I ...
12 views

### Distance of raft foundation outwards

Can you tell me (for USA) which code (or standard or guide) and in it where exactly I can see the distance required for the raft foundation, as far as how much it should extend horizontally beyond the ...
30 views

### I posted this before. I need help with the sequence. The sequence that I've gotten is quite weird, or I should say is messy

The link from the video: https://www.youtube.com/watch?v=ASNa_mxQbS4&feature=youtu.be I am trying to deduce the sequence and processes from the video. Something have gone wrong. I know this ...
25 views

### How to determine the stiffness matrix for finite element matrix

I'm having difficulty understanding how the stiffness matrix for finite elements is obtained. I am only having a difficult time understanding how to obtain the matrix values for K from the given ...
7 views

### FEM matehmatical methods

Are all advanced methods used in FEM, other than the Direct Stiffness Method, also ultimately based on Direct Stiffness Method? If not is there still a common starting point? Why did other methods ...
8 views

### Why do the anti-resonant filters in servo controllers operate on the velocity output and not position?

I've been looking into implementing a cascade controller for a motor control application that has a position, velocity, and torque control loops. Because the system we are positioning can experience ...
32 views

### Pump Power Question

Consider I have a pump sized to deliver 200 gpm of a fluid with a specific gravity of 0.7 and a total differential head of 60 ft of water. What is the hydraulic horse power? To calculate the hydraulic ...
16 views

### What are the major differences between the Instruction Set Architectures of a GPU and a CPU? [closed]

I have to give a presentation as a class assessment on any of the architecture features of a GPU (like hardware arch, ISA etc). I have decided upon ISA of AMD's GPU. I am not sure though what are the ...
13 views

### Mathematical definition of elastic materials [migrated]

Physically, elastic materials are materials which return to their original state upon complete removal of applied mechanical loads under isothermal conditions. In the book "Mechanics of ...
13 views

### Applying finite element analysis to solar panels [closed]

I am new to finite element analysis, but I was wondering if it would be effective to use finite element analysis to map the heat of solar panels, and draw conclusion based on data?
16 views

### What is theoretical (physical) limit of maximum data stored in MicroSD card?

There was time (more than decade ago) when I got 8 MB (yes, not GB) SD card for Nokia. At that moment, the maximum storage on ...
39 views

### 0 energy one way valves [closed]

Is there such thing as a check valve that takes no energy from water for water to pass through? What is the name of this/these check valve type/s? I barely know anything about engineering, just have ...
29 views

### Is there an upper limit to how fast a self balancing one wheeled vehicle can become while also being able to safely stop?

I've recently come across pictures of segway/hoverboard like self balancing motorcycle type vehicles that were supposedly able to become as fast as a street legal scooter. I kept wondering how they ...
47 views

### Fiberglass camper plus steel trailer

Hello to all of you with more expertise about engineering than me...and anyone else that is curious. I like to fantasize about projects, so this may be more of a thought experiment, but I'll throw it ...
24 views

### Where can I find the best mechatronics forum? [closed]

Where can I find the best mechatronics forum in the Stack Exchange or are there any other better forums out there besides Reddit?
24 views

### Why do some metals with bcc structure show ductile-brittle transition in charpy impact test?

I was learning about the charpy impact test and came across the graph on this webiste that shows the impact energy for bcc and fcc structures as a function of temperature. I tried searching for an ...
64 views

### How to measure absolute zero vacuum in pumps

Note this is a pure water pump, a 100w 8 meter regenerative turbine pump. Not a vacuum pump. Maybe the reason it cant get lower than 20 inHG is because its not a vacuum pump? Or is the analysis the ...
22 views

### detachable press magazine lock case

detachable press magazine lock case Any idea of what is the proper name of this locking mechanism ?? I been searching for it and can't see to find the same one I'm looking for( note this has nothing ...
21 views

### Type of mortar question [closed]

What type of mortar to be used for historical building? Is it low strength mortar? Historic mortar? Are they both the same? How about type K? Or type O mortar?
35 views

### Are these oscillations normal in a boiler?

I recently helped upgrade an old (±20years) 4ton boiler (heavy fuel oil) with some monitoring instrumentation. I decided to have a look at the data and I'm not sure if these kind of oscillations are ...
31 views

### Does the strength of a servo motor depend on the motor or the power?

I am making a life-size robotic dog, and i am having trouble with getting it to walk as it is too heavy for my 4 micro sg servos. Can i make the servos more powerful with more power? If not i can just ...
21 views

### Can you get the ratchet mechanism out of a socket wrench by itself? Anyone know where if so?

Title pretty much says it all; looking for a reversible ratchet hub for a special latch that I'm designing. Definitely open to any ideas/sources that the community at large might have. Thanks!
30 views

### Mesh generation in FEM [duplicate]

When a frame structure is analyzed using a FEM computer software, does the program still generate mesh, even as a line mesh, on frame members, or we must do it ourselves?
42 views

### Does Finite Element Method use direct stiffness method?

Does Finite Element Method use direct stiffness method? Or it is another mathematical method? We definitely use direct stiffness method to solve frames. FEM is based on entirely this or depending on ...
505 views

### What is a tolerable amount of elongation in steel?

I was looking at the elongation of various steel alloys, and the numbers were in the 10-20% range. Is this the amount of elongation at the point of failure? If so, what is the percentage of ...
61 views

### Can I safely cook on High temperature paint?

Like a million others, I have a set of enameled cookware that has seen enough use that the enamel has boiled, burned, or chipped off down to the cast iron substrate. Surprisingly, the outer painted ...
34 views

### Braking movement of a chain through a pulley or sheave

I am attempting to build a rotating climbing ladder, similar to the one below. The structural supports will be different, but the mechanism of chain (or cable) running in a loop over pulleys/sheaves ...
22 views

### How to make a 500+ psi water gun staff

I would like to create a life size lego Bionicle Aqua axe(gali nuva Type or gali master of water Type). The problem is unlike The trident in this video: https://m.youtube.com/watch?v=NK6MWt7vpVE&t=...
43 views

### How can I find deflection in a member that doesn't have a constant area moment of inertia?

I'm trying to calculate the maximum deflection in a simply supported member with a uniformly distributed load. The trouble is this member does not have a constant area moment of inertia. I've drawn a ...
18 views

### What is the use of streamlines in Fluid Mechanics when velocity fields seem sufficient?

So, streamlines are a family of curves which, for every instant in time, are the velocity field envelops. And in general, envelopes of a vector field are the curves whose tangent vector at each point ...
23 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 ...
43 views

### What is the maximum temprature that could be achieved by compressing air?

We know that compressing air produces heat but is it possible to achieve temprature of 700degree C just by compressing air. If not what will be the maximum temprature that could be achieved?
26 views

### Best solution to fix loose bolts problem, on delicate/ fragile surface?

Most common practice to fix loose bolts is using washers, but while using washers and tightening the delicate surface gets damaged, so what are better alternatives to fix loose bolts problem
18 views

### Can air be ionized using microwaves?

I have been doing a good bit of research lately into a new form of electric "jet engine" developed by researchers in Wuhan, China; in the article summarizing the technologies used to produce ...
35 views

### I'm trying to deduce how this Automated Packaging System from the video works in terms of the sequence, the cylinders used and the instruments used

This is how it goes..... Link to the video: https://www.youtube.com/watch?v=ASNa_mxQbS4&feature=youtu.be For the cylinders, I guess they use Cylinder A for activating an effective mechanism to ...
21 views

### Simplifying the soda gun mechanism

I'm looking to design a push button mechanism similar to the soda gun where water is forced to pass through a single passage based on which button has been pressed. What are the different approaches I ...
8 views

### Import Coordinate System as Marker in MSC Adams

A very simple question, yet I couldn't find an answer: I created a simple part (e.g. in SolidWorks) with one solid body and two Coordinate Systems. I would like to place my Joints, Revolutes, etc. in ...
20 views

### Transformer Phase Fault

I have a transformer for troubleshooting. It is a 3 phase DELTA-WYE Step down (11KV/400V) transformer, the low side voltages (secondary) are Line to line voltages: RED-YELLOW : 400 V YELLOW - BLUE :...
502 views

### Is it possible to build an efficient Electric Vehicle engine with minimal to no computing control systems?

First of all, I am neither an electronic nor a mechanical engineer, so if some of what I say sounds ignorant, that's most likely because it is. I have been thinking about this for a while now. I love ...
24 views

### How to interpret the phase plot from an accelerometer on vibrating machinery

Attached is a plot of amplitude vs frequency and on the inset phase vs frequency. I have constructed this phase plot via $\arctan\left(\frac{Im}{Re}\right)$ How can I interpret the phase plot or ...
34 views

### Modeling the structure vs FEM

When you model the structure to be analyzed with a structural analysis program, indicating the beam elements, shell elements, nodes, rigid links etc... The analysis is still called Finite Element ...
53 views

### How high will a flywheel catapult launch a payload?

First off, this is not a homework question or anything like that. I'm trying to build a catapult to launch a payload using a flywheel as an energy device! It goes like this: The flywheel spins up to ...
16 views

### What is the pressure of water-dew resulted from cooling of atmospheric air down to dew point temperature?

Suppose, In a room, Air is at 1 atm presssure. So should be the pressure of any water surface in the room. If the room temperature is cooled downed to dew point temperature, vapor (moisture) will ...
16 views

### how to Implement linear tetrahedral elements for finite element computations? [closed]

I am trying to implement 3D tetrahedral elements in my finite element code (which works fine for linear triangles and quadrangles in 2D). But my simulations are crashing with tetrahedral elements. My ...
15 views

### Can the signal reflections from seismographic surveys be intercepted and interpreted to produce valid results

I am watching the news about Turkey conducting seismographic surveys in the Eastern Mediterranean and from day 1 I have been wandering if a "listener" can record the sound produced by the ...