Questions tagged [mechanical]
189 questions
8
votes
3 answers
Mechanical advantage of the 3-ring release system
I'm quite curious about the 3-ring release system used in parachutes, as described in this Wikipedia article:
https://en.wikipedia.org/wiki/3-ring_release_system
I wonder why is this system so popular? I've been told it's nearly ubiquitous in the…
S. Rotos
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6
votes
1 answer
Identify this bomb disposal equipment
A recent news item featured this photo of a WW2 bomb being prepared for detonation.
Can anyone identify the purpose of the large widget sitting on the bomb? it's got a lot of cooling fins on it, and there appears to be fan on the right hand side.…
ConanTheGerbil
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5
votes
3 answers
Why does this thing that is not a screw have a screwdriver slot?
I am (partially) disassembling an old sewing machine to clean it up.
While removing the bobbin winder, I found this thing that has a screwdriver slot, but it isn't a screw.
This is the part:
It came out of here:
It is actually held in place by a…
JRE
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5
votes
1 answer
Quick return mechanism for spring-loaded screw
I am looking for a way to convert rotary motion to linear, but it should take less energy to get back to initial position than when going from initial position to the end position.
Specifically, a screw mechanism pushes a spring with multiple of…
PSz
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4
votes
1 answer
How does this pawl mechanism work?
From 507 mechanical movements, No. 63, we get the following diagram and description.
Jumping or intermittent rotary motion, used for meters and revolution-counters. The drop and attached pawl, carried by a spring at the left, are lifted by pins…
Sam Gallagher
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4
votes
1 answer
4 Gears in a Circular Pattern - Calculating the Proper Distances for Meshing
I have recently been working on a gearbox for a robot. I have this pattern of 4 gears with each gear connected to its 2 neighbors. It looks like this:
You will probably notice something though. Large gear on the right and the small one in the…
Ben L
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4
votes
2 answers
What is Saint Venant Principle?
I am having problem with the application of Saint Venant principle.I have heard that quite often we use that knowingly or unknowingly.I would be very greatful to anyone who would explain this very explicitly to me.
Rajorshi Koyal
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3
votes
1 answer
Why/when do we use a transition fit?
I'm self-learning a bit about preferred fits and tolerances and was wondering why transition fits were even a thing.
Clearance fits I understand, applications where you don't want parts to touch and "clear" each other.
Interference fits are for…
TwoWaySpeedOfLight
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3
votes
2 answers
Parallel beam load cells, force transfer and maximum load
I'm going to experiment with a parallel beam load cell like this one: https://cdn.sparkfun.com/datasheets/Sensors/ForceFlex/TAL220M4M5Update.pdf. I've read somewhere that for a setup shown on this picture:
the response of the cell is largely…
Paul Jurczak
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3
votes
3 answers
Torque and RPM calc
started by designing the gear meshing, and now I need to calculate some parameters to determinate if this meshing works for me.
The system considers an electric motor, which technical parameters are:
- Power supply: 220V/50 Hz
- Motor power:…
Joaquin Osses
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3
votes
1 answer
Clutch role in a micro hydropower
I've recently visited an old (about 60 years old) micro hydroelectric standalone installation. Total electric power is about 3 kW A/C.
A local told me between generator + fly-wheel and turbine there is a clutch.
Question is: what is the role of a…
mattia.b89
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3
votes
3 answers
Moments of Fixed-Fixed Beam
I have a quick question related to the topic of mechanics of materials.
If I were to have a beam that is fixed at both ends and has a central point force, do moments develop at the fixed supports?
e.g.
I was thinking, wouldn't there be an absence…
Justin
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3
votes
2 answers
Why do 2-stroke engines burn more oil?
Of course, most 2-stroke engines require oil to be mixed with the fuel (I appreciate there are 2-stroke engines that don't require this). Therefore, it makes sense to me that oil will be burnt during the combustion process, given it is mixed with…
PhysicsGuy123
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3
votes
1 answer
Scanning and modeling my personal vehicle for aerodynamic simulation
I have this pickup truck that I love dearly. I often change the aerodynamic configuration of the truck when I use my camper shell, or roof top tent, etc.
Is there a reasonably easy way to create a mesh model of my truck from images so that I can use…
C Jones
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2
votes
1 answer
Torx, Hex, Philips or Slotted screws
I mostly use M2.5 size screws. I got some brand new Torx screws but when I tightened them for the first time, either they stripped or the bit of the screwdriver got twisted. What could be the reasons? I used to use hex head bolts. This is my first…
lovedrinking
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