Questions tagged [friction]
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Rover Steering Torque
I would like to calculate the required motor torque to turn a rover wheel whilst the rover is stationary. I have modelled the friction force as a distributed force acting equally along the width of ...
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Minimum power required to drive a vehicle with a Swedish type omni wheels
I'm trying to find the minimal power needed to drive an omidirectional 3-wheeled robot. I already asked in Robotics Stack Exchange and they didn't respond yet.
From the equation $P=Fv$ I know I need ...
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Most efficient electricity generation in a wide flow of water
I'm wondering what the best method is for generating electricity in a wide river. The assumptions here is that it's a strong flowing river. It is very wide and we're allowed to put an electricity ...
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How do you calculate the chain tension required when compressing bulk material over a conveyor?
Bulk material is conveyed over a slat conveyor, and the material is leveled with overhead rollers while being transported in the conveyor to maintain an even material height. Most of these "levelers" ...
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How to calculate traction force w.r.t. rotational speed of a shaft mounted at a certain angle on a surface?
I am designing a new mobile robot platform and i need a generic solution for the robot in order to establish a proper mathematical modeling. My question is about calculation of the traction force of ...
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Friction Clamp/Brake Conundrum
I'm trying to calculate the amount of torque I need to put into my braking mechanism in order to hold up a weight. The weight is 18kg at the end of a 170mm arm. this should result in an approx. 30Nm ...
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How much horizontal force would it take to keep an object from slipping, using surface area?
I'm trying to figure out the horizontal force ($F_{P}$) needed to keep an object from slipping for a claw mechanism I'm designing. The given variables are the coefficient of static friction ($\mu_{_{s}...
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Effect of friction (or horizontal motion) on vertical surface deformation
I am trying to model the dynamics of some system.
In summary, the system consists of one horizontal linear actuator that drives an object along a planar surface and one vertical actuator that brings ...
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Where to find Ball and Revolute Joints with friction
I am new to design. Where do I find bearing joints that stay put? Suppliers? I am looking for.
A ball joint that has friction so that it stays put after it is moved. I was looking at modeling one ...
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What would be the Force Balance on this situation:
I'm struggling to find the correct Force balance in the following situation:
The black parts are hard stopers.
The blue part is moving perfectly aligned with the Y-axis in the negative direction.
The ...
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Forces acting on a weightless member
A weightless bar is pinned at the top of a triangle with N weight. Both rests at the horizontal plane.
There is a horizontal force F acting on the weightless bar, and a given coefficient of friction μ ...
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Bolted plate static and dynamic friction explanation
I will not go into the exact details of the engineering problem. Still, I kindly ask for some help with a proper explanation because I am having trouble explaining the correct principle in this ...
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Smallest possible rolling resistance
So, question is how to achieve the lowest possible friction in a scenario where there is a steel bar rotating AGAINST the circular frame at high rpm. Now, when it comes to sliding friction lowest ...
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Deriving the amplitude of a coulomb (dry friction) damped spring
This is my first time posting anything, but I could not figure out the derivation of the amplitude of the spring for the 4 first oscillations. I am not acquainted with the effect and calculations of ...
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Pressure drop in a CFD simulation of an air flow too small
I am simulating a turbulent air flow through a rectangular channel with the goal to match measured velocity profiles and the static pressure at certain points. My problem is that the pressure drop in ...
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Why do engines with cylinder offset not suffer from increased frictional losses on the compression and exhaust strokes?
I recently watched the D4A YouTube video on cylinder offset, and for the most part it makes sense. Longer power and intake strokes, lower frictional losses on the power and intake strokes, greater ...
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Can you explain mathematical and mechanics formulation of equation in Junker 1969 paper on self-loosening of fastener by vibration?
Can you help me to understand how the first equation in the paper 'New Criteria for Self-Loosening of Fasteners Under Vibration' by GH Junker, 1969 is derived? I'm not able to understand the ...
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If building a DIY screw jack, would it be beneficial to add a gimbal to the jack nut, and/or to the screw attachment?
The screw jack will be used twice daily.
It will be made out of M24 8.8 grade threaded rod and nut.
The nut will travel 300mm, to raise a weight of 50kg by 800m, via a pivoting lever arm.
The parts ...
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What would be an ideal material to use for O-rings on a canister in a lubricant-less, high-velocity pneumatic tube system?
I am interested in building an experimental lubricant-less pneumatic tube system in which the canister will be propelled up to a high-velocity, reaching a peak velocity of approximately 100 m/s before ...
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Friction force between two wheels at constant rpm
I have two tangent wheels pinned at their centers /which coincide with the center of mass/ and torque is applied to one of them (both roll without slipping). I want to find what force would they exert ...
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How Can You Calculate Force to Overcome Friction From an O-Ring Seal?
I essentially have a piston in a tube that is sealed with an O-Ring and actuated with a solenoid.
The friction of the O-Ring however, is higher than estimated (guessed as far as I can tell) by the ...
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Belt conveyor roller spring
I wanted to know if anyone could help in this area.
I want to create an inclined conveyor belt where, when a cargo box reaches the top of the conveyor belt, the rollers sequentially move down (maybe ...
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How does the mechanics of left-handed scissors differ from right-handed/standard scissors?
So I've read that my right hand with a left-handed scissor "pushes the blades apart" (same with my left hand with right-handed/standard scissors), but I couldn't find out why this happens or ...
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Self Locking Brake Question
I've been staring at this problem for statics for quite a while now and I just don't understand it. The question states:
"The brake is to be designed to be self locking, that is, it will not ...
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Friction coating aluminum parts in lieu of anodizing
I have an application, 6061-T6 aluminum cylinder, and piston - approx 6" dia for both, O-ring on position. The piston is under 80-100 psi, room temp and stroke are a couple of inches.
Typically, ...
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Will this pulley system work?
I want a system to move something in the opposite direction to the driven thing, but twice the distance. I'm thinking the below system of pulleys. I just wonder if it will actually work or will it ...
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Why is friction problematic on small mechanisms with multiple parts?
This recent video concerns scaling down a nerf gun. Apparently a major problem (mentioned at 2:46) is the fact that friction "multiplies exponentially". Can someone explain more precisely ...
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Pivot Point with Low Friction
Inspired by this question, I am looking for a low-friction pivot for a clock pendulum. The design uses magnetic repulsion to keep the pendulum going. A magnet is attached to the bottom of the pendulum ...
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Which of these two cases will have the most friction?
I have a structure colored in blue which we are looking directly downwards on (birdsview). Its high up in the air, and the only thing keeping it from falling down is the friction surface (red) between ...
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Head loss coefficient for a valve with respect to both the open position and flow rate
This question talks about the head loss coefficient for a valve, i.e., $K_{L}$ for $h_{L} = K_{L} V^{2} / 2g$ where $h_{L}$ is head loss.
First, head loss coefficient for a valve with respect to the ...
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How to calculate press load for an interference fit with no friction coefficient between the materials (shaft & hub)
Press-fit load calculation always takes friction into consideration and gives you the load expression as follows,
$$F = µ\cdot PA$$
where µ is the friction coefficient, P (Interference Pressure) is ...
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How can I reduce noise from pushrods in an assembly without using grease/oil?
I have an assembly which consists of a row of vertically-oriented nylon pushrods (each 5/16" in diameter, colored green in the attached pictures), and two black pieces of laser cut delrin ...
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Why carrom coins have the circular profiles on them?
Why do carrom coins have these circular profiles on them? At first I thought that this will reduce the friction as area reduces, but quickly recalled that friction for solids don't really depend that ...
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How can I reduce static friction in a small rotary encoder?
-- Note: I've flagged this as unlikely to be a quality question. I've refined it and rephrased it as a Mathematics SE focused one instead. Find it here.
I am using a rotary encoder as a pivot point ...
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Why robotic Lawn mowers are curved body structured?
Why robotic Lawn mowers are curved body structured as shown in image ? Is the curved body structure called aerodynamic ? What's the technical reason for it ?
For reference image :
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How to stop a leg from sliding?
One of the legs of a bed is bent (I believe it buckled). The bent can be corrected to be straight, however under the application of load to the bed, the leg will slowly return to the bent position. My ...
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Calculate pipe size and friction loss for an agricultural project's water system?
I'm in the process of designing a water system for our regenerative agricultural project in the Horn of Africa.
I'm looking to install a ≈1000L water tank on a 3 meter stand which will gravity supply ...
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Where would I place a bearing between 2 surfaces?
I'm a high-school engineering student, and for my final project I wanted to make a robotic arm.
However, I'm stuck on how to minimize friction between 2 surfaces (both made out of aluminum 6061-T6) ...
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Hydraulic Brakes - Why motorcycle brakes more powerful than bicycle brakes?
I was wondering why motorcycle brakes have so much more stopping power than bicycle hydraulic brakes (Than can be found on mountain bikes for example).
The rotor has a bigger size which gives better ...
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Can epoxy bond two Aluminum alloy beams?
The bicycle component manufacturer Shimano makes crankarms named "Hollowtech".
Hollowtech crankarms are meant to be both strong and light. As the diagram below (source: Shimano) shows, the ...
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Dynamic forces in Simulink
I have the equation of motion:
$a = \frac{1}{m} \left( F_1 - F_2 -F_{fric} \right)$
where a is the acceleration and m is the mass of an object. $F_{fric}$ is the friction calculated as:
$F_{fric} = B \...
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How to create a friction-based cable exercise machine?
What would be the best mechanism to create a friction based cable machine? The point of this machine to only have resistance to movement not when the cable's stationary and without the momentum of ...
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To reduce friction losses, is it better to have one single large ratio stage, or multiple smaller stages for worm gear?
If I wanted to have a 49:1 total reduction, would there be less friction losses with a single stage of a 49:1 or two stages of 7:1 and 7:1?
Google has not been much help. My gut says that I should use ...
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Why is the open-front bike stem design so widespread despite that it may be inferior to the closed-front design?
Context
Even major bicycle corporations have the occasional
product recall on handlebars.
It's easy to see why. The bike itself is a gentle, light, and nimble ~10 kg (for a road bike) object, whereas ...
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Force Required to Keep Ball Rolling
I am attempting to recreate a demonstration that someone told me about. A hollow steel ball rolls around in a non-metalic bowl, electromagnets keep it going. I obtained a steel ball and a glass ...
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Is there any material that has a higher kinetic friction than static friction?
Is there a material that has higher kinetic friction than static friction?
You can assume it's sliding on any surface you want.
Better if you come up with one that has this property on a standard ...
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Collecting a released rope with a proper speed
To simplify the problem, I liken the problem to a ship approaching the shore and a device wants to collect the rope in such a way that the rope is neither stretched too much nor released to the extent ...
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Passive magnetic bearing coefficient of friction
Imagine two axially-magnetized ring-shaped permanent magnets in a repulsive configuration where one is levitating on top of the other (and somehow radially constrained so the PMs remain ~concentric). ...
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Can Friction Pendulum Bearing/System (FPB/FPS) suppresses the effect of an earthquake from every direction or only from one direction?
Can Friction Pendulum Bearing (FPB) AKA. Friction Pendulum System (FPS) suppresses the effect of an earthquake from every direction or only from one direction?
Please take a look at the tests which ...
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Do asperity junctions break every time a machine starts to rotate?
After reading CONTROL OF MACHINES WITH FRICTION by Brian Armstrong-Helouvry, some questions rised.
The main question I ask you is:
Suppose two metal surfaces in relative motion first in static ...
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