Questions tagged [mechanical]
The mechanical tag has no usage guidance.
220
questions
10
votes
3
answers
4k
views
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 ...
- 2,269
6
votes
1
answer
211
views
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 ...
- 303
5
votes
4
answers
264
views
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 ...
- 151
5
votes
1
answer
664
views
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 ...
- 93
4
votes
2
answers
10k
views
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 ...
- 243
4
votes
0
answers
258
views
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 ...
- 51
3
votes
1
answer
3k
views
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 &...
3
votes
1
answer
66
views
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 ...
- 335
3
votes
2
answers
2k
views
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 ...
- 355
3
votes
1
answer
59
views
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 ...
- 33
3
votes
1
answer
353
views
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, ...
- 219
3
votes
1
answer
795
views
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. ...
- 33
3
votes
2
answers
524
views
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 ...
- 167
3
votes
1
answer
466
views
Calculate Torque Required
I am working on a school project that requires me to build a machine. I have designed the machine but I am stuck at torque calculation. The problem goes like this, the machine supposes to rotate a ...
- 31
2
votes
4
answers
105
views
Inverting motor polarities automatically to close and open a door
Hi,
I need to build a device that opens a chicken coop door.
The idea is quite simple, a motor connected to an axle that pulls a string up just like a wench. It would be activated by a relay timer ...
- 21