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 ...
- 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 ...
- 22.6k
5
votes
Accepted
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 ...
- 11.4k
4
votes
Accepted
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 ...
- 10.9k
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 ...
- 11.4k
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&...
- 41
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 ...
- 6,949
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 ...
- 7,297
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 ...
- 24.2k
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 ...
- 22.6k
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-...
- 295
1
vote
What weight on a still stepper motor?
It looks like I found what I was looking for in a linear actuator.
https://share.temu.com/cTUa8ElFOMA
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 ...
- 1,320
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 ...
- 500
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 ...
- 22.6k
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)
...
- 24.2k
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 ...
- 24.2k
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.
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 ...
- 7,013
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 ...
- 285
Only top scored, non community-wiki answers of a minimum length are eligible