5 votes
Accepted

Lifting a cabinet using actuators or scissor lift

In a scissors jack design, items one and three, you'll have the least mechanical advantage when the assembly is retracted. Using drawer slides or the equivalent is a good idea, but will not provide ...
fred_dot_u's user avatar
  • 7,055
5 votes

Understanding net torque from an actuator

There are two things going on. First, even if this "actuator" can produce constant torque, the torque required to keep the load spinning will be at least in part a function of the spinning speed. ...
Olin Lathrop's user avatar
  • 11.4k
4 votes
Accepted

Mechanism of a manual Crank Adjustable Height Standing Desk

the crank handle is connected to the little black box, inside of which there are gears that rotate the metal shaft you can see running through the box and across the back of the table support. the ...
niels nielsen's user avatar
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
  • 6,874
3 votes

Actuate a tilting platform from a single point

Sounds like the mechansim in a "clicky-top" ballpoint pen. You'll need a rotating cylindrical ratchet mechanism; the solenoid plunger moves inside this cylinder. Here's a drawing from quora.com
Carl Witthoft's user avatar
3 votes
Accepted

Are vacuum actuated artificial muscles as hard to control as the pneumatic ones?

With a vacuum you are limited to the pressure differential between zero and atmospheric (~100kPa or ~15PSI). With pneumatic you are limited to the pressure differential between atmospheric and ...
DKNguyen's user avatar
  • 5,481
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
2 votes

Understanding net torque from an actuator

The torque rating for the actuator depends on the speed it's running at - as it approaches its "top speed" it can't deliver the full rated torque. The reasons depend a lot on the actuator type. For ...
Andy's user avatar
  • 275
2 votes

How can I build and maintain an accurate pressure on a fuel line without using a fuel pump?

Without a pump you will have trouble maintaining flow. The pressure gauge on a fuel regulator I looked for maxed out at 140 psi. You can build pressure with an actuator but it will only run till the ...
Gwydionforge's user avatar
2 votes

How can I build and maintain an accurate pressure on a fuel line without using a fuel pump?

Edit to clarify As of now, The question is a bit unclear. I imagine you want a largely pressureless fuel system, each cylinder has it's own solenoid pump that replaces the fuel valve on this cylinder ...
mart's user avatar
  • 4,781
2 votes
Accepted

How to convert 7.62cm linear motion to 150-180° rotary motion

As suggested a rack and pinion will provide a linear transfer function and avoids complex linkages. A variant on the rack and pinion is to replace the straight rack teeth with a taught cable and the ...
Entrepreneur's user avatar
2 votes

How to convert 7.62cm linear motion to 150-180° rotary motion

There are commonly used methods used in backhoes and cherry picker trucks to move the arms about 180 degrees with a single hydraulic piston. If you search for photos of backhoes or power line ...
Entrepreneur's user avatar
2 votes

Power/energy density of an actuator

Power density is defined and understood as the average power over the weight and/or volume of the actuator (depending on the unit). Here, it is understood as the effective power output divided by ...
ComradeH's user avatar
  • 175
2 votes

Electric linear actuator

Linear actuators commonly have mounting brackets that permit rotation about an axis with the appropriate bracket. In your application, the rotation would be required, as the lid angle changes as it ...
fred_dot_u's user avatar
  • 7,055
2 votes

Lifting a cabinet using actuators or scissor lift

Either one would probably work as long as you gear it properly; but like Eric Shain, I'd advise you to go with the scissor jack because it's simpler. However, because the force varies with the angle ...
Palbitt's user avatar
  • 239
2 votes
Accepted

How to constrain stepper motor inside case?

Constrain the driven shaft and use a coupling to the motor.
Solar Mike's user avatar
  • 15.6k
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
  • 7,055
2 votes

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

I asked our chemical engineer at work about this and she was able to source a NASA research project that tested and achieved almost exactly what I'm trying to do. They built an electrolysis generated ...
dutenh's user avatar
  • 31
1 vote

piezo actuator - higher displacement when under load?

To my understanding the blocking force is a measure of the maximum force generated by the actuator. The way the blocking force is measured might explain better the discrepancy. The piezo actuator ...
NMech's user avatar
  • 24.3k
1 vote

Hydraulic system dynamics modelling

If inlet flow = outlet flow, then your system will quickly reach a state of equilibrium. The pump spins to transfer fluid from node 5 to node 1. There would be some minor pressure difference due to ...
jrbe228's user avatar
  • 376
1 vote

calculating the minimum force needed to lift a rigid awning - class 3 lever problem

After idealizing the model a bit, we can assume that the set up is like on the picture. The panel $OC$ rotates around the point $O$. The linear actuator is $AB$, attached to the camper's wall at ...
Futurologist's user avatar
1 vote

calculating the minimum force needed to lift a rigid awning - class 3 lever problem

OP here. I found this answer as well: Calculate effort to raise hinged lever with distributed load - So F = (200 lbs * 80 inches) / (2 * D inches) If D is say, 20 inches then F = 400 lbs. Solving this,...
ssaltman's user avatar
  • 121
1 vote

calculating the minimum force needed to lift a rigid awning - class 3 lever problem

Your diagram is not clear enough. As it is the actuator would not work because it's deadlocked. There are many configurations of levers, links, and brackets to do the job, each with its own pros and ...
kamran's user avatar
  • 22.2k
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.
Ryan Griffith's user avatar
1 vote

Linear pneumatic actuator opening time - pressurise connection pipe

Flow rate of the gas into the cylinder will change according to the pressure drop. So first you have to model flow rate through the pipe to the cylinder, which you can probably model as a plenum. I ...
Tiger Guy's user avatar
  • 6,793
1 vote

What exactly are Large Hydraulic Cylinders used for?

Have been used on offshore oil rigs to get the platform level compared to the sea bed.
Solar Mike's user avatar
  • 15.6k
1 vote

What is the maximum actuator strength allowed by physics?

You can make an actuator arbitrarily (e.g. infinitely) strong providing you make it big enough, and this would be equivalent to using an arbitrarily large number of regular strength actuators, in ...
SF.'s user avatar
  • 6,135
1 vote
Accepted

Help with simple hydraulic circuit to use for a four legged Robot

If the first VMA 1.025 is acting as your pressure relief valve, you might be OK, depending on duty cycles/pressures/flowrates/etc...You do still build some heat flowing over that relief valve, but ...
Corey's user avatar
  • 404
1 vote

Using linear actuator in the limited space

Multiply the distance moved using a lever, but the input force needed increases...
Solar Mike's user avatar
  • 15.6k
1 vote
Accepted

air-dropping actuator for a small drone

I would recommend using servo (or other actuator) to pull a pin that is holding the load in shear. That way, as long as the friction of your system is low, the actuator will only need a fraction of ...
ericnutsch's user avatar
  • 8,136

Only top scored, non community-wiki answers of a minimum length are eligible