Questions tagged [design]
Questions about or related to design.
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What's the best way to design a joint with two fasteners?
When you're trying to design a relatively long joint with only two fasteners, what's the best way to arrange them? Since fasteners effectively radiate a circle of clamping force around them, what's ...
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What would be the best mechanism to rotate a plate from 0 to 15 degrees?
I'm designing a machine in a small university project that change position of a two-state gate. The two states shown in the Figure below are 0 and 17 degrees of elevation, correspondingly. The ...
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What is the difference between requirements and design specifications?
Working while employed at large companies, I was at times confused as to what was considered to be a requirement and how a specification differs from it. Upon reading more about it, I have discovered ...
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Using Density Correction Factors for Fans and Blowers
I've been researching fans/blowers and their use in pneumatic systems (particularly conveying systems), and I'm confused by the application of density correction factors. Let me describe a sample ...
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Help with scaling torque and forces?
I am currently designing a ground based digging drill, that hopefully will be accepted by a commercial entity. I am currently working on the preliminary design of the robot and am hoping to move to ...
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Limit state design/ LRFD of short steel columns
Why do we use the yield strength as the limiting strength in short column design when using limit state design.
Why is the full capacity of the material not utilized (as is the case with beams when we ...
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How is linear motion achieved in this automatic blackboard eraser?
In the animation shown below what can be the mechanism used for this purpose? I know it can be achieved by using rack and pnion gear arrangement. But how are this set up arranged in classroom ...
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product to tackle problem of senior citizens of our society who forget to take pills due to Memory Loss [closed]
For a lot of senior citizens of our society, taking medications is a necessity.
Although necessary,it can be tedious sometimes. More often, these
patients forget to take pills due to Memory Loss. Is ...
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Mechanical/electronic chalkboard cleaning device to replace the conventional duster to clean the chalkboard
The chalk board duster which is used by teachers to wipe the chalkboard seems very agonizing for them. What new mechanical/electronic devices can be devised to replace conventional chalkboard duster ...
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Is design of "Budweiser's bow-tie shaped beer can " feasible & unique from engineering point of view?
Is design of "Budweiser's bow-tie shaped beer can " feasible & unique from engineering point of view?
Can there be a better design than it?
Like the shape of can is inclined at ten ...
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Looking for specific bearing
I am new to mechanical engineering so I don't know the terms for different bearings.
I'm trying to make a honey extractor. I have a rotating basket made out of stainless steel that is going a maximum ...
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Wood Dimensional Stability
Between Glue Laminated and steel plate sandwiched between two wood beams, which one is more dimension-ally stable?
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What is "reversal" in mechanical engineering drawing?
I've come across these terms "reversals allowed" and "reversals not allowed" in a sample drawing while reading a GD&T course.
What exactly are these terms? What do they mean?
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Wind turbine that is efficiant from all angles [closed]
What shape propeller with a large surface are, would be best propelled from the wind from behind and from the side as well as the front while facing the sun?
I am thinking a pinwheel, but maybe there ...
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What are the factors considered in the development of the video game controllers over the years? [closed]
What are the ergonomics taken into account in evolution of video game controller over the years.
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How is mechanism used in modern projector different from intermittent mechanism used in conventional one?
Do modern projector used for digital class works on same old conventional intermittent mechanism and blocking of light
during change of frame.
What is principal used in modern projector?
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Would a centrifugal flyweight governor system slow down the descent of an object that is free falling down to the Earth's surface? (Revised design) [closed]
I am wondering if rotating flyweights would slow down the descent of a object that is free falling down to the Earth's surface.
Please reference the conceptual drawing below:
This drawing is showing ...
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How much torque is needed to mix melted marshmallow with rice krispie?
I am designing a robot to make rice krispie treats!
More specifically, I want to use a fork to mix the melted marshmallow with rice krispie. I am currently specing out the motor, and since marshmallow+...
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How the optical cd disc gets drawn in when we gently push it? what is the mechanism behind it?
We have seen CD drives that have slits. The CD gets drawn inside upon a gentle
push. how the CD gets drawn inside upon a gentle push? How it's mechanism works?
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Automated Teller machine detecting fake bank notes [closed]
https://en.wikipedia.org/wiki/Automated_teller_machine
Do ATM's detect fake bank notes and not accept / receive from customers giving them a "Fake notes detected" message on the screen?
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As a rugged and waterproof device, how does gopro dissipate heat?
I am new to designing rugged + waterproof products. I am curious about how to dissipate heat when the electronics are running and the ambient environment is even hotter. It seems like the mode of heat ...
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2
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Vertical gear shaft support
I have a question regarding how are the vertical forces on a spur gear shaft are supported. I am currently doing my undergraduate (in final year) and have only dealt with gearboxes where the shafts ...
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2
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Torque based bending on shaft
I wanted to see if the force acting at A (30 kN) would create a deflection from OB other than twist. In other words, would a force perpendicular to the axis of rotation cause anything other than ...
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184
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Choice of Datum Features and Number of Datum Features
Consider a rectangular stock section with a dowel hole and other features of size (FOS) on it. The dowel hole serves to locate the entire part.
Should my choice of datum features be what is most ...
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Switching a Circuit on-and-off In-step with the Rotation of a Drive-shaft (Mechanically)
I'm working on a project. The Salient part here is a drive-shaft connected to a bearing, onto which a simple circuit is mounted. I want to switch the circuit on every $π$ and off for the other $π$ of ...
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what is the difference between jblade, qblade, and xflr5 softwares?
I am working on a propeller design, and I've came through Jblade which helped me in the airfoil design, yet as I can remember, xflr5 can also do this...
doing some internet search, i found that Jblade ...
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Geometric constraints on Planetary Gears
I would like to design a single stage planetary gearbox using standard gears.
There appears to be three primary conditions to ensure the geometry of the gears will fit - correct center distance, ...
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2
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How did OXO manufacture this colander with such intricate wall feature?
Here's my guess, but I would love to hear another perspective.
I think this is injection molded. This colander has draft angles and the two mold halves use an intricate step-like wall pattern to ...
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Setup Invention Process in Engineering CAD Software
I need to develop a collapsible metal construction. I have a few specific prerequisites. Generally speaking, it will be something like a big construction toy, but not be a toy. It has the specific ...
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2
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Reduce stress on holes
I have an aluminium bearing holder attached to one end of an aluminium plate as follows:
The bearing holder is attached to the plate by two bolts on the bottom. The intended setup is to attach a ...
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214
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How are the electronics and chips inside the microwave protected from the microwave radiation/energy?
Let's say I put in an endoscope like camera with the lens at the inside edge of the box and the wire behind metal sheet. Here's a mockup:
Could use microwave reflecting or absorbing wrap to wrap the ...
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I need a roller setting where I input a 1 feet fabric and need it to be reduced and compressed about 9 inches and released back as 1 feet fabric
I have a requirement where I need to input 1 ft wide flexible 5mm thick fabric into a roller setting where my width is reduced to 9 inches and compressed and released back as 1 ft. I thought of using ...
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Technical term for loose drawers jamming more readily than those with tighter clearance?
A loose drawer or loose sliding parts in general jam more easily than ones with tighter clearance. There is a name for this problem but I can not remember what it is, and searching for "loose drawer ...
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How is motor torque related to capstan equation?
I know that capstan equation relates $T_{in}$ and $T_{out}$ as $T_{out} = T_{in}e^{u \cdot F_c}$, where $u$ is friction coefficient and $F_c$ is wrap (slip) angle. In my situation, the capstan is ...
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Cheap but durable design for a quick-to-assemble, portable globe?
This question has a bit of an arts & crafts / DIY flavour, but looking at those Stack Exchanges made me feel it fits better here. I have no background in any of these things, so apologies for my ...
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Could a Jacob's Ladder produce enough hot air for a hot air balloon?
I am curious to know if a Jacob's Ladder would produce enough hot air to keep a hot air balloon afloat, or in other words, that it could be a substitute for a standard gas burner used for hot air ...
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2
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Conservation of Energy (NO PMM's)
A consequence of the law of conservation of energy is that a perpetual motion machine of the first kind cannot exist. My question is this. Why is this concept so hard to understand for many people? I ...
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WEC linear inputs
I have seen some designs being made for linear generators for WEC(wave energy) applications. A buoy driving a shaft. But what if the shaft inside was a rack and pinion? If you converted the ...
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Does the rack for a rack and pinion often have or need to have the involute profile?
I am looking at designing a rack and pinion system that will be laser cut out of some plastic. While the cad system that I am using has a spur gear generator, I was looking at the design of the rack ...
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Why rotation factor of bearing for inner ring is 1 and for outer ring is 1.2?
V is a rotation factor to account for the difference in ball rotations for outer ring rotation vs. inner ring rotation.
V = 1 for inner ring rotation
V = 1.2 for outer ring rotation
From Shigley's ...
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When an elevator has two buttons next to it, ^ and v, what do they actually mean?
Both as a kid and as an adult, I've encountered elevators lined up next to each other, or single ones, which have two buttons on each floor (outside of the elevator):
...
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Permanant extension for Fastener
I have a fastener with an accessibility problem. At the time of installation, the fastener is at the bottom of a crowded box with obstructions varying stiffness (Metal Plates and harnessing). It is ...
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2
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Driving a lead screw using a universal joint
I have some issues regarding a lead screw.
It's used as the main driving system for a scissor lift which requires about 2Nm torque to operate.
This is the exact part if it matters:
https://www....
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Where can I get design specifications for phones?
I am designing phone cases for 3D Printing. I am fairly new to the field, however I cannot find design specifications for any phone at all, i.e. exact measurements for the positioning of cameras, ...
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What screw to use with 1.8mm thick countersunk brackets?
I have a few brackets that are 1.8mm thick with 4.5mm countersunk holes like this:
The countersunk machine screws that I've found have head heights of at least 2.2mm (some 3.2mm). This is taken from ...
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Stirling Engine Cooled Engine
Could a Stirling Engine replace the cooling system of an engine?
Instead of having a clutch and fan attached to the main drive shaft to cool an engine, could a Stirling Engine and clutch share that ...
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Design of fan pipe for propelling glitter
I am trying to create a prototype for a glitter shooting mechanism. It is worth mentioning that I have no experience with mechanical engineering or fluid dynamics. I think the below image describes ...
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Shaft Design for Motor Test Rig
I want to design a shaft for a motor test rig. The motor and generator are 48V and 1.5kW and the maximum torque produced by the motor is 18Nm. RPM varies from 2900-3100. What shall be my next steps? I ...
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Bendable flaps on sheet metal
I'm trying to cut some bendable flaps on aluminium sheets for hooking/clipping onto some fabric. The flaps I have in mind look like this:
Are these common features? Does anyone know the geometry of ...
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Why HMMWV's lights aren't located at the edges?
Hummvee has front lights located far from edges, closer to each other. That makes it harder to see edges of the vehicle in the dark.