6 votes
Accepted

Off-centre actuation

Does anyone know if this would be a good idea? The proposed design has poor rigidity towards torsional loads. It doesn't matter whether the actuator is off-center or if the load is off-center: if ...
jpa's user avatar
  • 1,943
6 votes

Off-centre actuation

Your mechanism is going to lock up like the old car jacks immediately, due to differential raising of the platform. I am sorry but it looks like a textbook example of what not to do. in most real-life ...
kamran's user avatar
  • 22.4k
5 votes
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What is this contraption?

It looks like it might be a air-powered propeller. You pump up the bottle with air, and the high pressure is used to run a air motor that spins the propeller. This might have been part of a toy ...
Olin Lathrop's user avatar
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4 votes
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How do I calculate the ideal travel distance of the ball screw per revolution of the stepper or per step for the following hardware?

Screw: M6 M6 coarse has a 1 mm pitch. M6 fine has a 0.75 mm pitch. Unless otherwise stated assume coarse, so 1 mm pitch. Your motor is 1.8° per step. This is 360/1.8 = 200 steps/rev. The screw will ...
Transistor's user avatar
  • 10.7k
3 votes

Linear actuator that extends more than its retracted size

already found an answer :facepalm:. It seens that telescopic linear actuator exists and have two screw inside of another. Here is a demonstration: https://www.youtube.com/watch?v=CYz1gQG_ijs&...
Italo Guedes's user avatar
3 votes
Accepted

How to vary the force output of a motor while stalled?

There is nothing inherently wrong with running a motor in stall. The difficulty is that the power dissipation may be higher than the motor can handle long term. Every motor can dissipate some amount ...
Olin Lathrop's user avatar
  • 11.4k
3 votes
Accepted

Do linear actuators need to stay powered once in place? If not, how can I lock them?

Some linear actuators are self-locking — they can't be back-driven by force on the output connection. A leadscrew with a fine enough thread pitch is one example, and since you don't need a lot ...
Dave Tweed's user avatar
  • 6,884
2 votes
Accepted

Can linear actuators be moved manually?

Your primary question, if a linear actuator can be moved with the power off, will be no, unless you find a mechanism specifically created for that purpose. These actuators are effectively a pinion ...
fred_dot_u's user avatar
  • 7,080
2 votes

Off-centre actuation

IMHO (and I guess you already know that), from a structural point of view putting 100 kg at 1/4[m] will create a huge amount of bending moment on a actuator that it is rated for 120[kg]. An although ...
NMech's user avatar
  • 24.3k
2 votes
Accepted

Single linear actuator lifting mechanism

As a quick basic estimation approach we annotate the following: The length of bar 3 = L Top and bottom bearing force on each box $F_b$ The height and width of boxes 4 and its counterpart on channel ...
kamran's user avatar
  • 22.4k
2 votes

Need a solar powered mechanical motor? that moves a leaver up and down low force and little distance on day/night

Most easy way is to buy inexpensive garden water timer. Simplest one contains ball valve with motor, two dials for setting watering period and time and is powered by two 1,5 V cells. If you wish non-...
Vladimir's user avatar
  • 295
1 vote
Accepted

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

If the changes are slow enough, a simple pulley with counterweight might do the job. Constant force hangers are used very commonly for piping, where you can find interesting designs using combinations ...
Tomáš Létal's user avatar
1 vote

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

I looked into the same problem several years ago. The best I came up with was small solenoids. You can get some for around $1-2 on Aliexpress. You still have to get somewhat creative though: the ...
Jerry Coffin's user avatar
1 vote

Motor Power for vertical lift in linear slide mechanism

Let's convert 7 inches to meters, 7x0.0254 = 0.1778m You need a motor that can produce an average speed of 0.1778m/s so it must have an acceleration of 0.1778*2= 0.3556m/s^2 Now we can calculate the ...
kamran's user avatar
  • 22.4k
1 vote

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

In general the ideal travel per 1 revolution of the motor, will be depended on two things: screw dimensions the screw dimensions (in your case M6) and more specifically the pitch (see image below) ...
NMech's user avatar
  • 24.3k
1 vote

CNC side linear rails

What happens in the arrangement is that you are applying a force away from the center of gravity. Imagine you have a pencil on a flat surface and you try to push. If you don't push it around the ...
NMech's user avatar
  • 24.3k
1 vote

Linear actuator with low vibration and low noise

I might look into medical equipment, I was looking at actuators the other day, and they weren't too expensive.
Ryan Griffith's user avatar
1 vote
Accepted

Sizing a motor for a floor jack-like mechanism

You determined the torque at A correctly. You can get the force at B using the same equations. 650 Nm / .1 m = 6500 N. Yes, it's a lot, 5 times the load, but not close to where you ended up. The ...
Tiger Guy's user avatar
  • 6,881
1 vote

Voltage controlled linear actuator with spring back

I suggest: joystick->arduino ->motor driver for arduino-> micro peristaltic pump 1) I need a failsafe. no prob as long as joystick returns to center position( joysticks usually have springs for ...
Manu de Hanoi's user avatar

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