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1500 questions
4
votes
2 answers
Multi-position bi-stable solenoids in a small form factor
I am looking for multi-position bi-stable solenoids. So far, I have only found one vendor1 with a 3 position bi-stable solenoid.
Are there multi-position bi-stable solenoids with more than three positions? How can a 3 position bi-stable solenoid…
Mahendra Gunawardena
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4
votes
3 answers
Why do we need continuum approximation in fluid mechanics?
We know that a fluid in reality is not continuous. It has spaces and voids between atoms and molecules.
Continuum approximation is a famous approximation that is taken in any fluid mechanics textbook. It says that even though the fluid has spaces…
Harshit Rajput
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4
votes
4 answers
Direction of fluid flow
Consider water flowing in a pipe, and I don't know the direction of flow. How to determine the direction of flow?
My approach-
I can use a pitot tube but for that I have to drill a hole in the pipe and I can't use this approach for fluids whose…
MechaTrex
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4
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2 answers
What is the cause of this cracking pattern in a simply supported beam?
Background
On May 5th 2022, a bridge was struck in Brantford, Ontario, Canada by a commercial vehicle. This vehicle struck a reinforced concrete protection beam placed on the on-coming side for the traffic lanes passing under the bridge. The beams…
Forward Ed
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4
votes
1 answer
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 on the internet) with a DSX80 desoldering…
swineone
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4
votes
0 answers
Maximum Slope of Truck Parking Lot
What is the maximum grade/gradient allowed for non-temporary (overnight or longer) parking/vehicle storage areas in parking lots for heavy-duty vehicles such as semi-trucks and buses?
All I could find is that the International Building Code allows a…
4
votes
2 answers
Cooling system to maintain 0.5 °C at 95% humidity
I am looking for some guidance on a redneck cooling system.
I need to store seeding trees at a temperature just above freezing, and at a humidity of close to saturation.
I only need the system for about 2 months of the year.
At present I use…
Sherwood Botsford
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4
votes
1 answer
What is this strange "French balcony" on a newly built house in California, USA?
While randomly browsing around in Google Street View, amazed by how surprisingly cozy they managed to make this neighborhood, I found something very strange. What looks almost like a "French balcony", but with no actual door that opens. It's just a…
Stoehr
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4
votes
1 answer
Best Practice for Tracking Vendor Firmware Rev
My employer has had me create a model of a vendor product (using OnShape) and make a simple drawing with some overall dimensions that we can hand to customers. However, they want to include the firmware revision of this product in the drawing. I'm…
Optimum
- 41
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4
votes
2 answers
Do yielded columns buckle?
A sufficiently slender column will fail under compression below yield stress by bowing, releasing it's axial elastic strain. This is called buckling. Depending on the slenderness of the column, the buckling may be fully elastic, or may involve some…
Abdullah
- 166
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4
votes
2 answers
Why does light bend after travelling half of the lens?
As light enters a denser medium from a rarer medium, it bends towards the normal. Why does the light bend after passing through point F & not E?
S.M.T
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4
votes
2 answers
What is the purpose of dead coils in the middle of a compression spring?
What purpose do dead coils in the middle of a spring serve? For example, this spring from a ballpoint pen has two dead coils at each end and two in the center of the spring. Why add dead coils in the middle? What advantage does this create, or what…
CBRF23
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4
votes
3 answers
Why shouldn't we use Bernoulli beam theory if deformations and rotations are large?
I was going through the basic assumptions made by Bernoulli beam theory. I realized that one of the most important assumption in this theory is that the deformations and rotations of the beams are supposed to be small, not large. I couldn't…
Rameez Ul Haq
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4
votes
1 answer
How to determine the dynamic response of a spring-mass system?
The Problem
I have the following system for which I would like to determine its dynamic response, taken from these lecture notes pg.20:
where the forcing functions are $u_1 = 1-U(t - t_0)$, $u_2=0$, and $u_3=0$, $U(\cdot)$ is the unit step function…
kostas1335
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4
votes
0 answers
DIY BLDC ESC problem is causing MOSFETS and motor to get very hot very fast, HELP
Hey everyone this is my first time reaching out to the community for help to see if someone can show me what I'm not seeing on this. Basically I am trying to make my own ESC for a BLDC and before anyone says the commercial solution is cheaper and…
Harry_CL
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