Questions tagged [geometry]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers
45 views
+100

Type of Lyapunov surfaces corresponding to a specific Lyapunov function

Consider the following Lyapunov candidate function: $$ V(x,y,q_i) = \frac{1}{2}x^2 + \frac{1}{2}y^2 + \sum_{i=1}^{n}\ln\big(\cosh(q_{i})\big) \tag1$$ where $q_{i} = \sqrt{(x-x_{i})^2 + (y-y_{i})^2} - ...
Teo Protoulis's user avatar
0 votes
1 answer
48 views

Is there a shape that when submerged in a fluid is stable across all axis?

When placing a jar in a body of water an air bubble can be formed. If the air bubble is large enough forces are equal and the jar will be buoyant and float on the surface of the fluid (see fig. a). ...
Geoff Beamish's user avatar
0 votes
0 answers
33 views

Mathematical descritption of spur gear undercut

I'd like to a plot spur gear in python (using matplotlib, but that is not important..). I've already worked out the involute curves, which can by parametrized easily and which define the main part of ...
mrklMik's user avatar
0 votes
0 answers
33 views

FEA meshing of irregular geometry

I work on the simulation of sand particles and usually use tetrahedral free-meshing to represent their complex geometries for finite element analysis. I have recently spent some time looking into ...
Jacob Wilson's user avatar
0 votes
1 answer
73 views

Profile and pressure angle definition in gear geometry

In gear geometry there are 3 main angles, which can be misleading: Profile angle Pressure angle Operating pressure angle Further for simplicity I would restrict the area of interest to "spur ...
Richard's user avatar
0 votes
0 answers
19 views

Drone Geometrical Shape

Drone Can Drones be designed with geometrical shapes viz Kite, Cylinder, Sphere etc?
Prashant Akerkar's user avatar
0 votes
0 answers
125 views

Find the Angles 1 to 3 so that the Reactional Forces Become Minimal

My question regards the following system: This system is supposed to be located in a plane, so it is 2-dimensional. It consists of three rods, which are connected at the ends. Meeting in the hinges $...
San Chairudo's user avatar
1 vote
3 answers
865 views

5 balanced masses on wheel with different distances between them

I'm looking for a way to calculate possible balanced positions of 5 equal masses on the circumference of a spinning wheel such that the distance along the circumference between the masses are all ...
spDuchamp's user avatar
0 votes
2 answers
156 views

height of partly filled tank

I want to derive an expression for the fill level of a water tank with the shape of like a rectangular frustum, similar to the one in the picture: I know the values: $a_1$,$a_2$, $b_1$, $b_2$ and the ...
Nil's user avatar
  • 61
0 votes
0 answers
51 views

How to calculate velocity east, north up having lat/lng/alt/time?

I have a certain values from a camera and wondering how the velocity east, north and up is calculated. Here are the values ...
code0x00's user avatar
  • 101
0 votes
1 answer
95 views

What is the most structurally supportive 3D Tessellation? The sort of thing you'd use to build chambers for an underground mansion

Hexagons are considered the strongest grid pattern, I believe, and that's why bees use them? They're an efficient use of space, with maximal structural integrity. I was wondering what a 3-dimensional ...
user38849's user avatar
1 vote
0 answers
27 views

What are some interesting applications of G2/G3 Continuity? [closed]

I've heard of CNC tool paths using splines to approximate G2 continuity to create smoother motion. Also, rollercoaster designs use G2 continuity to reduce shock from sudden changes in curve radius ...
Flywheel's user avatar
0 votes
1 answer
102 views

How do I calculate the angle of the handrail transition if both need to be set at 33 degrees around a 90 degree corner?

How do I calculate the angle of the handrail transition if both need to be set at 33 degrees around a 90 degree corner?
Daniel Hanson's user avatar
0 votes
0 answers
43 views

Piston that produces equal amounts of swing in a lever?

I am attempting to figure out an equation I've found for designing part of Walschaerts Valve Gear. The specific implementation isn't relevant here, because it's the math I'm after, but this is the ...
Rekov's user avatar
  • 187
0 votes
1 answer
85 views

Is there a geometry that meshes exactly with a rope?

I'm in a use case where the outer surface is a gear driven by a motor (that's the easy part) and the inner surface meshes with a metallic (iron) rope. When the part rotates, I want the motor and ...
ywa1n's user avatar
  • 23
0 votes
2 answers
85 views

At what steepness does a vehicle start rolling?

At what exact gradient does a typical vehicle in the following classes start to roll away when the brakes are released and the transmission is in neutral? I'm trying to design a super-safe parking lot/...
CoastCity Lapse 00crashtest's user avatar
4 votes
0 answers
141 views

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 ...
CoastCity Lapse 00crashtest's user avatar
0 votes
3 answers
178 views

Figuring out Geometry for Kreg 720

I'm making pocket holes to connect wood together with a jig, the Kreg 720. The 720 works by moving at an angle (which I'm trying to measure) to ensure the hole is drilled higher on thicker pieces. The ...
bonhoffer's user avatar
  • 155
-1 votes
1 answer
102 views

Help with engineering graphics

Please redirect me if this is the wrong place to post this, however I've been having issues with something for engineering graphics classes and need some help I'm supposed to draw two intersecting ...
Monola Brzoza's user avatar
1 vote
5 answers
180 views

How do I calculate surface area of dashboard through integration?

How can I calculate surface area of dashboard through integration. I traced the surface using pencil. I can calculate rough area but I want to calculate actual area through integration. The vertical ...
Ibrahim Omer's user avatar
0 votes
1 answer
70 views

Inside/outside test of any point on 2D plane?

Suppose I have one plane $Ax+By+Cz+D=0.$ I want to test $(x, y, z)$ is inside of this plane or outside. My attempt:1 Then draw normal N on that plane which point away from the observer Image1. If $Ax+...
S. M.'s user avatar
  • 113
0 votes
3 answers
268 views

How to calculate perimeter of spur gear?

I'm in need of some gears, but having them made by a machinist is very expensive so I'm planning to have them laser cut. Loads are reasonably low for any grade of steel, so I'm hoping it should be ...
php_nub_qq's user avatar
2 votes
1 answer
70 views

To stop or to go around?

Let us we are moving in a car. There is a wall in front of us, we need to decide can we go around it or not. It is known that width of the wall is $w$ and our speed is $v = const$. What is a simple ...
Constantin Werner's user avatar
0 votes
1 answer
37 views

Why is the area of upstream face of control volume a stated?

I cannot seem to visualise why the area of the upstream face of control volume is 2pir∂r, can someone pls clarify on why is this the case?
KSP's user avatar
  • 3
1 vote
0 answers
39 views

Does anybody know where this calculation for the mass moment of inertia for an eighth of a circle comes from?

These attached photos describe flaps which are a portion of a circle and equations are attached as the mass moment of inertia, but there are no descriptions. I am using this for part of my research, ...
alcopo63q's user avatar
0 votes
1 answer
296 views

horizontal angle of view based on distance from window [closed]

I am looking for an equation to provide me the angle of view based on a distance from a window. I'm only interested in the horizontal not the vertical.
user195166's user avatar
3 votes
2 answers
274 views

How to calculate miter angles for an angled stretcher

See the image below: When I lay this out in Fusion, I can get the angles but I can't figure out how to calculate it mathematically. The goal is to have the angled stretcher fully contact the upper 45&...
Mr. Mascaro's user avatar
4 votes
1 answer
164 views

How to trace a square with a reuleaux triangle

I am trying to trace a square (with rounded corners) using a reuleaux triangle and a single (circular rotation) motor. I've seen many animations (example) of this but do not understand how to make it. ...
Ankit's user avatar
  • 299
0 votes
0 answers
31 views

Is a pyramid considered axisymmetric? Why so?

I read a source, I will not reference the source on this platform. They stated a pyramid is axisymmetric. Can you explain why if yes?
Jay22's user avatar
  • 1
2 votes
0 answers
94 views

When calculating a car's suspension caster, after turning the steering wheel 20 degrees, why multiply by 1.5?

To calculate caster of one side of a vehicle, the steering wheel is turned 20 degrees to the left, and the camber is obtained; this represents the 'in' value of the front right tire. Then the steering ...
gimmegimme's user avatar
2 votes
2 answers
8k views

How to calculate meters per pixel for a given camera?

I am stuck on this problem for a while: I have a square-shaped camera, with: 1000 pixels on vertical side 1000 pixels on horizontal side I want to know the number of meters per pixel depending of ...
totalMongot's user avatar
1 vote
1 answer
56 views

How could I get the coordinates of the circumscribed circle giving the 3 points coords?

I have the coordinates of 3 points thrgouh which, a circle should pass . Having the coordinates of the points in 3D, how could I have the coordinates of the center of circumscribed circle ? also : if ...
FabioSpaghetti's user avatar
0 votes
0 answers
36 views

Program for creating a cylinder given its axis, center and radius?

I have data with the following normalized values: Unit vector for cylinder axis: -0.00270666, -0.01226211, 0.9999212 Normalized coordinates for cylinder center 0.01412114, 0.01074875, 0.00017004 ...
Dean R's user avatar
  • 1
1 vote
1 answer
100 views

Arc subtended by stretching of a conical spiral spring

I'm trying to work out the angle subtended by the stretching of a conical spring and I have a solution but I'm not 100% sure about it so would appreciate some feedback. An Archimedes spiral spring is ...
enea19's user avatar
  • 137
1 vote
1 answer
2k views

Calculating area moment of inertia for a beam with underslung plate?

In a number of designs, a beam will have an underslung welded plate attached, as shown below: In this sketch, a symmetrical standard steel beam/column of dimensions H1 x B1, with web and flange ...
Stilez's user avatar
  • 571
2 votes
3 answers
952 views

Calculate area of mesh?

I have expanded steel mesh that I use to make garden cages: I would like to know how much sunlight the mesh blocks. I think I need to calculate the area that the mesh takes up (per square inch) and ...
User1974's user avatar
  • 399
1 vote
1 answer
352 views

Equation used to obtain the adjustment angle of a pivoting lid support mechanism?

The following image shows a CAD model in its folded and unfolded form. I was able to successfully give it the ability for it to be adjusted between a 25 and 45 degree form, at 5 degree increments; ...
gimmegimme's user avatar
1 vote
1 answer
89 views

Building a half-arch of a specific height, while consistently using an angle divisible by 90

I am trying to construct a lift handle in the CAD Sketchup. The circled part of the image shows the arch I'm referring to. The program, Sketchup, has a 'tool' called push/pull, and another tool ...
gimmegimme's user avatar
2 votes
4 answers
3k views

Wrap a geodesic dome with a poly sheet: Minimize overlap & loose areas

I want to make a geodesic dome greenhouse (16ft wide, type: 3V 5/8). Source: http://geodesicdomes.ca/wp-content/uploads/2009/12/domes-fullsize.jpg I would cover a geodesic dome frame with clear ...
User1974's user avatar
  • 399
0 votes
1 answer
136 views

Difference in Diameter calculation using Solidworks and manually

When I try to create a flat form of a archimedes screw using Solidworks it gives me a diameter different from what is calculated manually basically using a Pythagoras Theorem. Can anyone explain the ...
Naman Choradia's user avatar
5 votes
7 answers
2k views

What makes scooters unstable at high speeds?

Scooters and skateboards are obviously meant for slower speeds, below 5 MPH. Typically if you go faster than that, it becomes harder and harder to control the scooter, and you will fall off. An ...
user16388's user avatar
0 votes
1 answer
165 views

Boolean Geometry Help [closed]

I just don't get the concept of Boolean Geometry... Can you help me understand how to solve these homework problems? Thanks!
Luke R's user avatar
  • 11
0 votes
1 answer
28 views

How to find the nearest locations around a given latitude and longitude point? [closed]

I have a database of locations. Each location is a latitude and longitude pair. Now for each query, I want to get top "X" nearest locations around a given latitude longitude point. How do I actually ...
Nagabhushan Baddi's user avatar
0 votes
1 answer
196 views

Calculate attitude quaternion from 2 vector measurements

I am using a method proposed by R. G. Reynolds to estimate attitude based on two vector measurements, taken from: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19990052720.pdf Suppose we ...
Rufus's user avatar
  • 1
8 votes
3 answers
2k views

Calculating moment of inertia for a hollow discontinuous circle?

This is a pretty simple problem, but I'm just not sure how to go about it. I want to find the moment of inertia of a discontinuous hollow circle. But since the shape is so irregular, I'm not sure how ...
tempestwing0101's user avatar
6 votes
1 answer
687 views

Do outer fillets|chamfers also reduce stress as inner ones do?

I kind of have an intuition or at least imagination about how fillet|chamfer of inner edges|vertexes reduce stress (concentration). But does that apply to outer edges|vertexes aswell? Maybe to a ...
hepe's user avatar
  • 61
6 votes
4 answers
3k views

Why are Whitworth threads angled at 55°?

You're probably thinking, "Well.. Why not? It's gotta be something.." Right? But 55° is kind of an odd angle if you think about it.. and it does seem like a pretty specific choice considering a ...
voices's user avatar
  • 201
0 votes
2 answers
130 views

What does this equation mean?

$$\propto \dfrac {\text {Cross-Sectional Area}}{\text {Volume}} $$ I've seen this equation on my textbook (physics). Let us imagine that there are two pen with $7$ and $3$ lenght. Which is harder ...
Cargobob's user avatar
  • 123
1 vote
1 answer
120 views

What is the most accurate geometry to represent earth

Currently software and maps represent earth in many different ways, the latest is Point Clouds as this is the most common surveying tools currently available. For the needs of visualisation, ...
Rott's user avatar
  • 13
0 votes
1 answer
438 views

Advice for designing internal structure of glider wing

I am interested in designing a scale model semi-monocoque wing for a glider. I've done some research on the framework and internal structure. I have found out about the spars, ribs and stringers and I ...
AkThao's user avatar
  • 117