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15
votes
14answers
25k views

What kind of math do engineers really use? [closed]

I am from the mathematics StackExchange section, many of my students are engineering students at University. I was wondering what kind of calculus do you real engineers use? I have known two engineers....
3
votes
1answer
238 views

Motor Driver board: limited current

I'm having some trouble using a motor driver board. I'm pretty sure its being driven properly since there is ~3V @ the output v.s. none when its off. However it should be supplying ~2A (rectifier ...
5
votes
1answer
134 views

Question about “uncertainty”

I'm a bit confused about all the different "definitions" of uncertainty? One can calculate "uncertainty" of a single measurement by simply checking how accurate the tool that is being used to do the ...
6
votes
1answer
156 views

Scale models of thermal plumes

I want to look at the thermal heat plume of a human in still air in a room. So I have a tank of water with a heating coil/cylinder in it. How do I calculate what the heat output of my heating coil ...
2
votes
1answer
173 views

How to divert solids from a downward vertical pipe

I am an electronics engineer trying to build one small underwater mechanical device (about 12 cubic cm) as part of a personal automation project. I have figured out the electronics for this, but I am ...
3
votes
1answer
1k views

How to design electronics to mitigate tin whiskers?

Tin Whiskers are a major problem in the design of electronic circuits and the manufacturing of electronic hardware. What are Tin Whiskers? How can electronic products be design to mitigate the issue ...
8
votes
2answers
2k views

What is the practical limit on the number of storeys in residential buildings built with monolithic reinforced concrete?

I have recently bought a flat in a 25-storey building. I wonder what is the practical limit for the number of storeys in a mass-produced residential buildings built from monolithic reinforced concrete?...
22
votes
4answers
6k views

What is a reason that handlebars fit to a motorcycle and steering wheel fit to a car?

What is the reason that handlebars are installed on motorcycles and steering wheels are installed on cars? Notice that the way to use both handlebars and steering wheels are quite similar, but a ...
3
votes
1answer
4k views

Is it acceptable to paint weathering steel?

Weathering steel is not typically painted, because it produces a thin rust layer that protects the rest of the steel from further corrosion. Would painting weathering steel be an acceptable additional ...
0
votes
1answer
557 views

Thoriated tungsten TIG electrodes were in use 45 years ago.What were their specific use and problems?

Some TIG electrodes in use in the early 1970's were marked Thoriated Tungsten and Non-Thoriated Tungsten. What were the specific purposes or properties for these TIG welding electrodes?
7
votes
1answer
1k views

Are standard structural bolts acceptable for all cold climates?

The specifications for standard (ASTM A 325) bolts do not list minimum service temperatures. I am thinking of outdoor applications like Alaska or Canada (lows of -60F) and wondering if the cold ...
5
votes
1answer
217 views

Best traffic control device/system for given situation

I am familiar with the round-a-bout/traffic light pros and cons, however, I've been tasked with deciding on a solution for the given parameters below. Currently, there is a two-way (four lane) road ...
10
votes
3answers
5k views

Why is it unwise to choose cylindrical horizontal beam

I heard that it is unwise to choose cylindrical horizontal beam. My question is why?
1
vote
1answer
343 views

What type of sensing element is used in Water Quality Monitoring Meters?

What type of sensing element is used in Water Quality Monitoring meters such as those pictured below? I might not be using the correct search terms. Some of these meters monitor Total Dissolved ...
3
votes
1answer
1k views

Tankless air compressor for electronics desoldering station

I purchased a Weller WSD161V soldering station (similar to this one, at least with regards to the pneumatic system I'm about to describe -- sorry, I was unable to find a manual for my specific model ...
0
votes
2answers
129 views

Is making a toilet flush backwards problematic? [closed]

The Coriolis effect impacts the way water tends to circle before going down the drain. Many (most, all?) toilets are designed to work with the Coriolis effect. I am considering a line of toilets ...
5
votes
1answer
83 views

Where to insulate Underfloor air distribution system in a temperate climate

I have a proposed underfloor air distribution system (UFAD) for a one level office in a temperate climate. Typically the demand for heating and cooling in this climate is about even for offices. ...
9
votes
3answers
838 views

Could air-launched space planes reach escape velocities?

Rockets like the Ariane 5 weigh hundreds of tons, but with about 85% of that weight being fuel, the payload fraction is only about 3% (~10-20 tons). Virgin Galactic is building suborbital space ...
4
votes
4answers
667 views

Can you get quality welds from a multiple metal wire feed welder, or do you need separate units for steel and aluminum?

The job site requires welding both aluminum and steel (each to themselves only) for different areas of the project. The contractor has a dual purpose wire feed welder (aluminum and steel) but I am ...
5
votes
3answers
1k views

What is the densest ceramic?

I know ceramics are generally considerably less dense than pure metals or alloys but sand is used in barbells for its probably cheapness, user-friendly and easy availability but its a decent density ...
12
votes
3answers
3k views

Measuring longer distances with high accuracy

I am involved right now in the fabrication of steel structures on the order of 5-50 feet long. Presently, we measure these structures with garden variety commercial tape measures. Most of the time, we ...
7
votes
3answers
1k views

Motor for a hydraulic pump in a hydraulic system

I am a complete beginner to hydraulic systems, and I've wanted to learn more about this area. I'm designing a hydraulic system that involves using hydraulics to push/pull objects using pistons. I have ...
2
votes
2answers
9k views

How do I manufacture a fillet?

What are the most popular and the most efficient ways to machine a fillet on an external edge of an object? If I were to use a CNC mill, what tools can I use for it, and how would the method change ...
7
votes
4answers
4k views

What bolts should I specify with Weathering Steel?

When using weathering steel (COR-TEN) on a project, what sort of bolts should I be using? I have yet to see fixings made of weather steel; presumably because the way it uses a sacrificial layer to ...
3
votes
2answers
238 views

Ensuring even flow in liquid pumping in distribution circuit under suction

I have a liquid circuit which looks a bit like that: The system is under suction, and the flow rate through each unit should be about 10ml/min. However, we noticed that unit ...
10
votes
3answers
2k views

Could a gold/{second metal} crown be created that would pass the Archimedes test cost effectively?

Many people are familiar with the story of Archimedes submerging a crown in water to identify if the volume of the crown was consistent with the volume of the same amount of gold. The test was to see ...
4
votes
1answer
178 views

Name of spring actuated component

I need to get another component like this but I can't seem to find any manufacturers / retailers. To describe it: It is spring mounted on a shaft and retained by bushing on the top and an enlarged ...
13
votes
1answer
1k views

Why are hyperboloid towers not popular anymore?

Hyperboloid towers were very popular in the end of 19th and the first half of 20th centuries - water towers, powerline anchor towers, sometimes tall radio towers were built using this design. The ...
7
votes
5answers
6k views

How do you attach something temporary to a smooth metal shaft?

I want to attach something small to the smooth metal shaft of a small motor (2-3 mm in diameter), like fan blades, but I want it to be temporary. If I make it too loose, then the fan won't turn at ...
5
votes
2answers
114 views

Can the production rate of labs-on-a-chip ever reach the production rate of silicon chips?

Labs-on-a-chip and silicon chips both have the potential - and in some cases have already reached the potential - to drastically scale down tasks, in these cases performing chemical reactions and ...
6
votes
2answers
705 views

Creating smooth shaft resistance

I am trying to emulate the resistance of a hand wheel which moves a table via a series of shafts and chains which turn an acme screw. I am switching to a CNC system that will allow the user to keep ...
5
votes
3answers
975 views

Mounting and Coupling an Encoder

I was wondering how to mount a small rotary encoder to a platform in order to measure how far a small treaded robot has traveled. We're using this tread/wheel set: We've tried epoxying the encoder ...
16
votes
5answers
822 views

Meshing of complex geometrical domains

When using the finite element method, I have always used either already meshed domains or very simple ones. From what I've heard, meshing complex geometries is often outsourced to specialized ...
0
votes
2answers
542 views

Possible Hazards of Software Controlled Systems (Ex. Airline GPS/Elevator)?

I am currently reading through a book on Software Engineering principles, with a lot of the content having to do with proper approaches to software development methodologies and project management ...
4
votes
1answer
1k views

How many units of HB are used for steel bridges?

Bridges in the UK can be assessed (to standard BA34/90) using an HB vehicle (to standard BD37/01). The HB vehicle is 16 wheel loads, each of 2.5kN times "units". For concrete bridges the number of ...
31
votes
3answers
18k views

How fast does solid waste fall in vertical drain pipes?

Some building are really tall, if you flush the toilet and the contents go into a pipe and straight down, there could be a lot of energy, potentially enough to cause harm to the sewer pipe at the end ...
9
votes
2answers
1k views

Soil swelling and mass/volume relationships

Given moisture content, Specific gravity of solids, initial volume, and weight. I'm asked to compute the moist unit weight, dry unit weight, and degree of saturation of this compacted soil. This is ...
9
votes
2answers
1k views

How do I form a budget for a mechanical research project?

I'm a mechatronics engineering student currently on workplacement. I've put forward a research proposal to develop an improved mechanical gripper used for automated product handling. The company likes ...
19
votes
4answers
5k views

What makes suspension bridges unsuitable for railways?

I recall reading in an old issue of Model Railroader an article about railroad bridges. In it, the author mentioned that you shouldn't have a model suspension bridge for a railroad track on your ...
6
votes
2answers
207 views

Cutting mechanism for a robot in confined spaces

I'd like to build an exploratory robot that can fit within confined spaces1. As the robot moves along the inside of a 4" pipe, it's likely to encounter some obstacles that need to be removed. ...
0
votes
2answers
335 views

Final speed of a truck on a slope?

I have a truck which weighs 190 kg and will travel 100m down a 38° slope. How I can find the trucks speed at the end of the 100m?
6
votes
2answers
108 views

Traction mechanisms for a robot in confined spaces

I'd like to build an exploratory robot that can fit within confined spaces1. What traction mechanisms should I consider to propel a robot along the inside of a 4" pipe? The pipe to be traversed will ...
19
votes
6answers
8k views

How to make smoke for a small wind tunnel?

I am making a small (desktop) wind tunnel for educational purposes, I want to have 10 fairly thick smoke-streams about 3cm apart. I have experimented with incense but the stream is not thick enough ...
2
votes
1answer
95 views

What is the name of the part that allows a steam wand to have a moveable joint?

On espresso machines, there is some kind of pipe joint which allows the steam wand to move while maintaining its seal. What is this component called?
6
votes
1answer
248 views

Controlling hydraulic cylinders with variable delay

Electro-mechanical systems typically used in robots have very low delays and are quite simple to build servo controllers for. Hydraulic systems are much less common in robotics and have delay due to ...
8
votes
1answer
723 views

What is the focal distance of an optical mouse?

I am trying to build an optical sensor for my old school, state property, standard french watt-o-meter. EDF ( Electricité de France ) has a gig which turns a wheel depending on watt consumption. The ...
2
votes
2answers
2k views

What are the longitudal tolerances of thread on metric nuts and bolts?

It's not exactly my area of expertize and I've spent a couple hours ears deep in norms, and I'm not really sure if what I found is correct (the figure I found was to the order of 1$\mu$m). When using ...
19
votes
2answers
2k views

What are the major differences between Engineering degrees and Engineering Technology degrees in terms of employability?

What difference in education occurs between two graduates, one with an Engineering Technology degree (be it Civil, Mechanical, Electrical...) and the other with the equivalent Engineering degree "...
8
votes
5answers
637 views

How can I measure the thickness of a sedimentation layer in a closed tank?

Biogas slurry often contains sand and grit and organic matter that eventually sediments. Clearing thetank from sedimentation is expensive (plant downtime, additional equipment) and dangerous. So it ...
3
votes
1answer
52 views

How is the long term reactivity of implant materials evaluated?

Various materials are implanted within the human body as a result of of medical need. Dental implants, stabilizing plates, arterial stents, and orthopedic replacements are all common examples where a ...

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