Questions tagged [linear-motion]

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Generate trajectory between 2 points to achieve a desired momentum

I need to plan path for robotic arm(having a tennis racquet as end-effector) whose aim is to hit a tennis ball in a specific direction(to return ball to the opponent). Now I have an algorithm which ...
48 views

How does the thrust rating of a push rod/linear actuator (I've seen it in both kg and N) relate to the amount of weight it can move?

I'm working on a custom RC project, and I'm needing to move a lever with a "weight" of 5 lbs. 5 lbs is required to actuate the lever, and I need to push it 5 mm. Gravity does not affect the ...
30 views

Autonomous vehicle lateral control

I am working on a control system for autonomous vehicles, i am using a kinematic bicycle model simulated on matlab simulink and the formula i used for the steering angle is given in the figures below ...
110 views

VDI Guideline 2143 Sheet 1: Motion rules for cam mechanisms; theoretical fundamentals

Hello Motion Control Enthusiast, I am a motion control student, and looking for your suggestion for a Free downloadable English-translated version of VDI Guideline 2143, theoretical fundaments of cam ...
48 views

In a lead screw mechanism with a fixed travelling nut, will the screw and its driving mechanism move instead?

https://www.youtube.com/shorts/tUkkOStjz8o Imagine this but upside down. Since the platform bolted to the travelling nuts will be pressed against the ground and will have nowhere to go, I reckon the ...
35 views

Accelerate an object in a current-carrying coil

I'm currently trying to come up with some concept ideas for a physics game / riddle. The player has to get an object from one side of a horizontal, current-carrying coil to the other end of the coil ...
1 vote
111 views

Method to achieve a constant force no matter the actual velocity when under load

So, this might be a somewhat strange need, as I don't seem to see many resources on this. I'm trying to create a device where I can set an amount of force for it to generate, and when it would behave ...
54 views

Reciprocating motion in alternating tracks

I’m trying to find a solution for a simple feeder mechanism where a spring-loaded ”piston” gets pushed in a linear motion, and then on the way back it switches to parallel track, enabling it to be ...
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47 views

High speed linear actuator/motor design

I need to make a linear actuator to compress a spring 80mm in 0.1 seconds. This is a speed of 1600mm/s. It takes around 15kg of force to compress the spring. How can I design a linear actuator for ...
1 vote
38 views

Linear actuator that extends more than its retracted size

I'm trying to build my standing desk and has been studying a lot of them, but have not found a CAD or Technical Drawing of them mechanism. Obviously, as an Engineer, I assume that it uses a Lead Screw ...
1 vote
32 views

What motors would be suitable for linear actuation in 1-2mm footprint?

I need to control simple braille (text for blind people) array with tiny rods. I don't necessarily have to control the precise location. A linear actuator with on/off states would be enough. However, ...
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107 views

Using a Lead Screw To Create a Two Stage Clamping System

I want to use a motor to drive a lead screw that first brings down a platform that locks into place and then controls a secondary platform to apply pressure but using only a single motor. As an ...
38 views

Is there a rotational-to-linear machine that doesn't allow the slider to impart torque while _between_ extremes?

Consider a machine for converting rotational motion to rectilinear translation, such as a crank slider or scotch yoke. When the slider is at either of its two translational extremes (where the crank ...
128 views

Rotation of point in 3D space

I want to rotate a point (3,4,5) by an angle 45 degrees(0.785398 rad) in 3D space. I have used the standard DCM matrix in the order Rx, Ry and Rz. Where, $\theta = 0.785398 [rad]$  Rx= \begin{...
1 vote
254 views

Lifting a table using linear rails and linear actuators

I'm trying to design a coffee table for a tightly constrained space that can lift up to become a dining table. I've drawn the CAD for this design, but I'm concerned that the moment arm on the linear-...
1 vote
94 views

Driving an air cylinder with ignited hydrogen/oxygen gas mixture from fuel cell?

Summary: I need to build a linear actuator that has a very fast actuating speed but fits in a very small space. My Question/Idea: Electric gearmotors, c02, and air pressure, are all ideas that come to ...
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2k views

Simple mechanism to convert linear motion into 180 degrees rotation

I want a simple mechanism to rotate something 180 degrees when another thing moves linearly past/through it. The below is what I have, but it can only work with an offset, so the movement is never ...
65 views

How to achieve sliding motion like this between two blocks?

I want to make a construction of two boxes, that by default would be stacked one on top of the other, but linked in a way that would allow the top box to slide off and then move down so that they are ...
196 views

Understanding the importance of 'pitch': For ball screws and timing belts

I searched here and even asked at McMaster-Carr, but even they couldn't provide an answer for me-- So, say you have either a ball-screw, or a timing belt-- Of course, in either case, having the right ...
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27 views

Determining the balancing force for a system of unequal masses for given scenario (angular-momentum, moment-of-inertia, thought-experiment)

Have already asked this on physics-site but has been closed. As such trying here! This question is basically a thought experiment. Let's say there are two pulley's P1 and P2 having equal radius R and ...
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1 vote
38 views

Looking for a mount with 3D play to it

I'm building a lift bed in a van. The basic idea is that each corner of the bed is mounted on a linear track actuator, bed goes up, bed goes down. I want to be able to control each actuator ...
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1 vote
49 views

How do you make custom springs and where could you buy them?

A friend and I are working on a combat robot that uses a special drive. This drive requires a spring with a large wire diameter (over 3mm), a large outer diameter (40-70mm), and a large pitch (60-90mm)...
94 views

Looking for a linear actuator that can carry a transverse load? Does such a product exist?

I am looking for a product that works like a linear actuator where you can control how far it extends but it can also hold a transverse load at the furthest point of extension. What I am looking for ...
97 views

How do linear guides work?

I am new to the office and I wanted to ask about linear guides like shown in the picture: (source: https://www.nskeurope.de/de/linear-motion-control/products/linear-guides.html) Are the carriages able ...
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37 views

Differential Drive Kinematic Constraint Determination

I'm working through a paper to better understand Differential Drive Mobile robots and I'm a bit stuck(fairly early in the paper) on how one of the constraints is derived. The paper is here, https://...
28 views

To design the system of a rectangular small shaft moving in and out in a completely mechanical way without remote control

In my setup , I have designed a system in which a body will rotate and execute rectilinear motion down the screw along its thread . upon reaching the bottom most point I want to make a system in which ...
39 views

Design of a linear actuator that is only 5 mm wide

I have to design a linear actuator with a maximum movement of 3 cm back and forth and a maximum force of 5 N. The only constraint I have is that it can only be 5 mm wide. There's no real constraint ...
2k views

Spring and damper in series, equation of motion

For the motion in fig 4.1 (a), please check the description of this system in the images above, everything should be there. I get it, assuming the positive direction is downward, the spring tension is ...
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1 vote
61 views

how are larger leadscrews (14mm diameter and up) fixed in place?

So looking at 12mm lead screws and below, it seems like a common method for fixing them in place is to use pillow blocks. The pillow block has set screws which clamp onto the lead screw, and you're ...
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34 views

I'm trying to understand an equation from a motor simulation $\dot w_i (u_ i ​ ,w_i,l _i ​ , \dot l _ i ​ )$

I have a simulated motor and I'm not understanding the math to control it. This is the equation for the force of the motor, also called an 'actuator'. $\dot w_i (u_ i ​ ,w_i,l _i ​ , \dot l _ i ​ )$ w ...
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1 vote
70 views

Is there such a thing as a double roller/bearing? Two rollers/bearings that share one axis, but can roll independently. [linear/pivot]

I'm looking for two track rollers or bearings that share an axis, but can roll independently of each other. Ideally, they are compact as well ($\leq 1 \text{ in}.$ diameter) and can handle a moderate ...
• 111
143 views

Retractable linear mechanism with a retractable drive for servo control

I am considering a mechanical system that is able to retract and extend via servo control but with the drive mechanism being retractable itself. Doing so I will be able to have a multiplied retracting ...
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97 views

Help with design of linear actuator

I am working on an automated gate positioner for a drill press. This gate will move back and forth by a set distance so lining up the drill press is automatic. I have tested with the Z axis of a cheap ...
247 views

How do I calculate the total force required for a linear actuator? [closed]

How do I calculate the total forcerequired for a linear actuator? The image enclosed shows a series of door panels, each with a cam that i would like to connect to a linear actuator on the right hand ...
71 views

Motor Power for vertical lift in linear slide mechanism

I want to pull up and down 10 kg metal cylinder at 7 inch vertically by using linear slide mechanism in 1 second. What should be the motor rpm, gear type, torque, watt etc? Otherwise how to calculate ...
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2k views

Ideas for mechanism for quick reciprocating motion - a 'truly' mechanical switch

I need a mechanism to switch the vertical position of an assembly in as square a profile as possible - i.e. a normal crank mechanism produces a sine wave profile, to explain myself better. I've seen ...
419 views

Raise/Lower 350lb Sawmill Head 12v Motor Specs

I am new to this site and have a problem to solve in an area that I’m pretty lost in. I can usually figure stuff out with the help of the internet and some digging but not getting real traction so ...
53 views

Linear solenoid mount

I have a linear solenoid with a tapped M3 hole at the end of the plunger, like this: I need to connect this plunger to a lever, so I want to add a mount which has a connection something like this: ...
1 vote
112 views

Linear motion with triangle profile

I am looking for a way to generate a linear motion with a triangle motion profile for my hobby project. The travel distance should be 6cm (so 12 cm for round-trip) with constant speed 1.2 m/s or ...
1 vote
196 views

Is a pneumatic cylinder in general a linear or rotary actuator?

I've just begun to learn pneumatics and I'm really confused where the pneumatic cylinder falls under in the categorization of what kind of mechanical motion it is suppose to produce. I've seen one ...
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5k views

How do I calculate the ideal travel distance of the ball screw per revolution of the stepper or per step for the following hardware?

Question How do I calculate the ideal travel distance of the ball screw per revolution of the stepper / per step for the following hardware (I believe this is called the lead)? Background I have a pre-...
72 views

If aboard a train being driven along a track by centripetal force, would it feel like you were on a regular straight track?

Question: If aboard a train being driven along a track by centripetal force, would it feel the same as if you were on a regular straight track? I hope this isn't subjective, I think there is a right ...
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321 views

How much force can an acme lead screw handle?

I have a stepper motor that claims 425 oz*inches torque. I want the lead screw to span 2' supported on both sides. I'm trying to decide what diameter lead screw is strong enough to not be damaged by ...
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1 vote
133 views

In circular motion , why do we say this is centripetal acceleration

Let us say a particle is moving in a circle with Uniform circular motion . Then , if I take an equation like this . $\theta$ = S(Arc length or Total distance covered ) / Radius of circle *( time ...
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1 vote
44 views

Did not understand this regarding angular velocity

It says $V\sin \alpha$ (component of velocity perpendicular to OP) is the cause of angular displacement. How is it? if only $V\cos \alpha$ existed, we need not turn over head to always to look at a ...
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41 views

Calculating Gearing Ratio from Constrained Rotational Linear Arc and Horizontally Opposed Rotation

I'm 3D printing an aircraft throttle unit as a POC and am trying to calculate the gearing ratios that are required in order transfer the full range of linear motion into a directionally opposed sensor ...
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254 views

I'm currently developing a linear motion system which will have to withstand a large offset load (see image below). There will be two rails, each with a carriage on, which will be connected by a beam/...
279 views

Single linear actuator lifting mechanism

I have inherited a DIY build and I have some doubts about its design. Have a look at the following diagram: 1 is the linear actuator. It's quite beefy 2000 lbs 12" stroke. It is installed in an ...
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1 vote
209 views

CNC side linear rails

I've been wondering why most (hobby) CNC machines have two actuated linear rails like this: Besides the extra force for moving the spindle, is there a need for both rails to be actuated? Could the ...
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