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What system could replace a spring?
3

What system could replace a spring?

What system could replace a spring?

(OP)
Hello,

I am doing a internship and I am working on a device that has a spring to generate force, by pressing it downstairs and hold it in that position. When a release button is pushed then the spring goes back to it's normal form and releases the power.

Now I am looking for a few system that could replace the spring, because my boss wants get rid of the spring.

Has some one a idea that could replace a spring and still generate enough force?

hopefully someone can help me!

RE: What system could replace a spring?

compressed air

RE: What system could replace a spring?

Various rubber/elastic materials, electric solenoid, different form of spring, see-saw with counterweight.

RE: What system could replace a spring?

You need to use the right terminology.

The spring does not generate force. That comes from the thing or weight that is compressing it.

Force is force. Power is force times distance divided by time.

Releasing the spring doesn't release the power, it releases the force.

Why does your boss want to get rid of the spring? Is there ant movement which needs to be taken up or not. Having a spring implies that there is a movement.

First define your issue/ requirement before looking for other options.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: What system could replace a spring?

Find a senior engineer who is familiar with that product.

Even better, one who is familiar with the problem with the spring.

From first principles, nothing is more simple then a spring for trading work for force. So it is essential to understand the problem that requires solving.

RE: What system could replace a spring?

A few questions:

1. What is the distance the spring is compressed?
2. What force is required?
3. Is it important that the force varies when the spring is released? i.e. spring force follows a linear path because of the spring constant
4. How frequently does this operation take place?

Some options:
1. Gas spring
2. Counterweight on a cable etc.


Like MintJulep says, a spring is a very simple and predictable way to accomplish the task.

Kyle

RE: What system could replace a spring?

(OP)
Hello everyone,

To anwser a few question, so that everything is clear.

1. The distance that the spring is compressed si 5 cm.
2. the required force is 10 Newton
3. No the system needs to generate 10 Newton.
4. The device will be used 5 times and will then be thrown away.

My boss his opinion is that the spring isn't the best solution, so if we can figure out something else that does the job it's better.

But I also agree with you guys that the spring is very simple and predictable. But there must be a similar device that does the same job.

And just to be clear this is just to see what similar systems there are.

RE: What system could replace a spring?

So is movement to generate the force required or not?

If yes then you need some sort of compressible material ( rubber, plastic, whatever)

If you just need a force of 10N then a piston with air or liquid could do this or maybe a solenoid or a weight of some sort.

what is pressing down on the spring to create the force at the moment?

A sketch/picture would help a lot here.

Using anything 5 times then throwing it away sounds very wasteful....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: What system could replace a spring?

If a spring is already doing the job, you must define why a spring is not desirable, and which characteristics of the spring you want to get rid of. You can't just say, "I [or my boss] don't want to use a spring." If you want something that will do the job "better", you have to define what "better" is.

RE: What system could replace a spring?

It's basically disposable. Five compressed air "capsules" inside a bladder that expands when each capsule is electronically/somehow breached. There will have to be a relief valve to deflate the bladder and release the force.

RE: What system could replace a spring?

Instead of "simplify and add lightness", let's "complexify and add obfuscation".

Explain to the rest of us, the big picture. What does this gizmocontraption that you are trying to re-invent do? What is the problem with having a spring?

Springs don't just magically release and reapply their load. Something else pushes, compresses, stretches, twists, or whatever to them to reapply their load. What is it that does that, in this case?

More information ... better answers.

RE: What system could replace a spring?

And there are many styles of springs; compression or extension, coil or leaf or other geometry, and a bunch of others.
If there is something undesirable about the current one then likely the easiest action (without adding undue cost and complexity) is to look at other spring configurations.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: What system could replace a spring?

A counterweight would accomplish what you describe.

RE: What system could replace a spring?

Martijn Roks,

How about a different kind of spring?

Actually, your spring stores energy.

Energy = Work = Force × Distance

If you wish to store and then release mechanical energy, you need a spring. If you don't want to do this mechanically, would a solenoid do?

--
JHG

RE: What system could replace a spring?

Not knowing the type of object that incorporates the spring, a possible replacement to the spring could be a device having the motion of a screw. Obviously the design would be more complicated since the required power could be from pneumatic or hydraulic medium.

RE: What system could replace a spring?

For 5 operations nothing could be simpler than a spring - maybe your boss is just giving you sonething to do - - the next request will be design a left handed screw-driver.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: What system could replace a spring?

(OP)
T explain it more I added a picture in my anwser.
1. Is the button that attached on the spring
2. the box/device the spring is located in
3. Is the spring
4. Stick with rounded tip in it.

So what it does is: that you need to push the button (1) down so the spring will be pushed together. Once it is down the button will attach to the stick (4) and the stick will hold the button in place, because it is held back by a "release button". So now the energy of the spring is stored until the release button is pressed. When the release button is pressed the button will shoot upwards with the attached stick.

Now we wanted to see if there is another simpel system that could do the same thing as a spring. Because we need to destroy the device it would be easier if every material is the same, so it could be destroyed and reused.

So if this clears thing up and some one has a idea that would be helpfull. Because I don't need anwser what concluded that my boss just give me things to do etc. This isn't my boss, but my school who said I should look into it and to do research.

I was thinking maybe we could use magnets that push eachother away. Is has the same principale in my opinion.

So if someone has some new insides or something like that let them hear!

RE: What system could replace a spring?

Interesting school that would ask you to replace something cheap and simple to make with something more expensive and more complicated; is the school named "Goldberg" by any chance?

springs can be made from a number of metals. magnets can be made from a number of metals. Magnet will need some sort of fixed and guaranteed separation, making the enclosure more complicated; magnets need to be attached with adhesive, making "destroyed and reused" more complicated. How does that simplify "destroyed and reused?"

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: What system could replace a spring?

Quote (Martijn Roks)

so it could be destroyed and reused.

The highlighted concepts are mutually exclusive.

Where is the "release button" in your sketch?

What is the purpose of this thing?

Engineers must work with quantifiable criteria. Thus far there are none stated.

Given what you have explained so far I would choose a spring.

RE: What system could replace a spring?

Don't use magnets, expensive touchy to work with and hard to recycle.
What is the housing and button, plastic?
Have you looked at plastic spring elements. Maybe leaves in order to give you enough force.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: What system could replace a spring?

Look at the mechanism of a retractable ball-point pen - the kind where you press the button on the end to make the writing end poke out, then press it again to make it retract.

That mechanism contains ... a spring.

RE: What system could replace a spring?

I agree. Sounds like a pen to me.

Screw mechanism instead?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: What system could replace a spring?

I'm seeing a five cylinder revolver shooting five blanks. Or if the boss wants cheap, get a Saturday night special and don't load the sixth cylinder. Or surprise your boss by loading the sixth cylinder and asking for a raise for improving the product.

RE: What system could replace a spring?

Agree with Ed,I would take a wild guess that the spring is "undesirable" because the rest of the assembly is plastic that is metled down and so they don't want to have to take it apart and remove the spring first. Using the same material to create a spring seems to solve that problem. Potentially the spring could even be integrated into one of the other parts as a flexure/snap fit style device.

GSTP

Graduate Mechanical Design Engineer
UK

RE: What system could replace a spring?

Google plastic spring.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: What system could replace a spring?

I'm seeing a lot of responses here but no one is asking the key question - why does your boss object to a spring? I suspect he has had some bad experience with a spring and is trying to avoid a repeat. Find out more about his objections. What doesn't he like? Is he afraid of failure of the spring? Is it not repeatable enough? Is it too difficult to assemble? His objections could be many things.

Once you know more you will also know which direction to go. Right now you are just guessing at a solution that MIGHT make him happy.

RE: What system could replace a spring?

Take a look at Compliant Mechanisms, this is essentially what GSTP has suggested : https://www.youtube.com/watch?v=97t7Xj_iBv0.

You could combine parts 1,2 & 3 into a single molded component saving costs and will get bonus points from your school for being innovative.

RE: What system could replace a spring?

Quote (Jboggs)

no one is asking the key question

I asked that two days ago.

Also of note... OP stated there is no boss. He is a student. This is a student post.

RE: What system could replace a spring?

(OP)
Hello everybody,

The spring is undesirable component of the device, because there where problems with it in the past. Thats why they want to have a other simple component and I think the leaf spring will do the trick.
I want to apologize for my uncertainty over the project and I really appreciate the anwsers/feedback all of you are giving me.

I am going to look into all the solutions you guys gave me and make decisions based on that.

Greetings

RE: What system could replace a spring?

Quote:

The spring is undesirable component of the device, because there where problems with it in the past. Thats why they want to have a other simple component and I think the leaf spring will do the trick.

Springs WORK.IN.ALL.SORTS.OF.CHEAP.STUFF. To throw our springs because of "problems" is just plain bad engineering, unless it can be proven that springs couldn't do the job in the first place. Your school/class is doing you a great disservice here. Learning from mistakes is way more important than moving on and making different mistakes on something else.


Quote (Thomas Edison)

Many of life's failures are people who did not realize how close they were to success when they gave up.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: What system could replace a spring?

I agree, I've seen designs with relatively small, solvable problems thrown out in favor of new clean sheet designs that introduced huge new problems and in the end complete project failure.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: What system could replace a spring?

Quote (Martijin Roks)

The spring is undesirable component of the device, because there where problems with it in the past

A really important part of engineering is asking good questions.

WHY is the spring undesirable?

WHAT were the problems with it?

WHEN did the problems occur? In the PAST. Are the problems no longer occurring in the PRESENT? What changed.

It is critical to understand the problem before attempting to solve the problem.

You don't appear to be there yet.

RE: What system could replace a spring?

Five tiny air bags and a hat pin.

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