# Tag Info

## Hot answers tagged actuator

5

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 for a balanced lift if there are loads applied that are not uniform over the cabinet's bottom surface. Your selected motor, with a thirty to one reduction should ...

5

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. There will be some friction and other forces that increase with increased speed. Viscous friction increases linearly with speed, and other effects, like air ...

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I'm going to cheat by referencing the patent. ;) Automatic Bar Controls owns the Wunderbar site and has a patent on the product. The patent is US008925769. The actual detail drawings don't seem to be available there though, so you have to get it straight from the US Patent Office listing. The name of the patent is: Wireless spout and system for dispensing. ...

3

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 right hand end of that shaft enters the support leg on the right which has another gearbox in it that rotates a shaft leading down the length of the support leg. ...

3

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

3

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 of speed for your application, wold probably be a good choice.

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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 example with a DC electric motor the coil induces a back-EMF at higher speeds causing a tail off on the torque curve. For other actuator types there will be ...

2

A,B,C, and D are normally closed solenoid valves. The valves with the arrows above them are pneumatic check valves, such as reed valves, with the arrow indicating flow direction. So basically, with no power, pushing the piston in and out of the air cylinder causes an inlet check valve to open and a check valve to the flask to open and you act to ...

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The main concern in the design is the exposure of a high tolerance surface to the elements. Both systems can be made very robust. The hydraulic system would need a shroud to protect the rod from damage. Additional rod wiper rings would be a good idea too. The electrical motor with gearbox would be very easy to protect and would be the most reliable if it is ...

2

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 cylinder you make is empty. If you use a large actuator and a large cylinder (the size of a gas can) you might get it to work but that is not an efficient way ...

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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 and is controlled by your microcontroller. So the fuel supply is not done via supplying a constant pressure to a carburetor that does the mixing, but by ...

2

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 pinion teeth with a pulley. This mechanism is sometimes referred to as a capstan and bowstring. https://en.wikipedia.org/wiki/Capstan_and_Bowstring If you need ...

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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 maintenance trucks you may see a type of linkage. Here is a photo This video is crude but you can definitely see the 3 moving parts and how they interact. The red ...

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Constrain the driven shaft and use a coupling to the motor.

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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 gear design with a very high reduction ratio. You'll note in the link you provided that heavy lift mechanisms such as a motorcycle lift and a medical bed are ...

2

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 opens. Both ends of the actuator have to rotate about the fastener, usually a pin or bolt. Replace either end with a quick release pin, which allows you to ...

2

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 of the scissors, you'll need to gear it down somewhat more than my suggestion. Lifting the setup is around 201 joules (41 kg * 0.5 m * 9.8 m/s (g)), and it would ...

1

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 cons. I show a very basic bracket welded to the owning at 35 degrees. Depending on the length of this bracket and the actuators play you can roughly calculate ...

1

I might look into medical equipment, I was looking at actuators the other day, and they weren't too expensive.

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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 would assume this is a differential equation version of head loss flow. So as the mass of air enters the cylinder you have the pressure increase in the ...

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Have been used on offshore oil rigs to get the platform level compared to the sea bed.

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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 parallel. If you want that force limited to a specific area, instead of spreading it as wide as needed, your one hard limit comes from general relativity. Your ...

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Multiply the distance moved using a lever, but the input force needed increases...

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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 like above, depends on your system. I had a similar issue in a design recently so I feel the need to mention it. If you go with a dump, put the valve right after ...

1

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 weight (or volume) For example, if your actuator is made from $2kg$ of DE and delivers $5W$ worth of power, then the power density is $5/2=2.5W/kg$ Thanks @Phil ...

1

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 the force (like a mousetrap). You would attach the pin to the servo arm such that it is as close to the rotation point as possible to give you the most torque. ...

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I've designed and built using a 3D printer a release mechanism to drop one kilogram payloads from a DJI Phantom 3 copter. It used the same principle as the 3-ring release mechanism patented by Bill Booth for cutting away parachute canopies in the event of an emergency. The concept behind this system is that the first "fold-over" takes the primary load close ...

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The answer is fairly simple: for data input, video recognition is far less cumbersome than an exoskeleton reading the user moves. For output - force feedback - our senses are way too complex; the technologies currently provided are all snake oil and money grabs because they would be extremely lackluster had they came to fruition in current form. The ...

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Pneumatic probably not. Something that fast would probably be belt driven servo, or linear servo such as LinMot.

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Try a bi-stable lock/unlock mechanism per drawer. A solenoid or perhaps two flip the state of the lock. No power is needed to stay in any one state, only to flip states. Since the solenoids only need to be run for a short time, like maybe 50 ms, the large current spike can be supplied locally by a capacitor. That capacitor can then charge up more slowly ...

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