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Distressed Nerd: Alternative to thin spring steel?
6

Distressed Nerd: Alternative to thin spring steel?

Distressed Nerd: Alternative to thin spring steel?

(OP)
Figure out a solution and I will name my pet hamster after you.

Can anyone tell me a plastic or cheaper to manufacturer alternative to this design - 7'' diameter circle made out of spring steel wire that easily deforms and returns to circle shape. It needs to able to simply crumple it up in your hand and then release and it springs back to original shape.

Please see video for more information (in the video it is enclosed in fabric)- Link

RE: Distressed Nerd: Alternative to thin spring steel?

2
The metal is called Nitinol.

Please start addressing your pet hamster as "Your Highness".

RE: Distressed Nerd: Alternative to thin spring steel?

The star was mostly for the "your highness" part.

Dan T

RE: Distressed Nerd: Alternative to thin spring steel?

(OP)
Your highness - the question was for a plastic or cheaper to manufacturer alternative to this design.

RE: Distressed Nerd: Alternative to thin spring steel?

I see this is from someone with an electrical background. I'll trade you for a cheap way to make semiconductors out of plastic, preferably injection molded nylon. Being able to injection mold a functioning circuit board in one shot would be worth even more.

The guys who made that device are already using the cheapest material for the job.

RE: Distressed Nerd: Alternative to thin spring steel?

DistressedNerd,

You can do this with plastic if you make it very thin. How much force do you need to exert. Why does it have to be plastic?

--
JHG

RE: Distressed Nerd: Alternative to thin spring steel?

I assume from the lack of information in the OP that the part must last forever over an infinite number of uses. Or maybe just one time? Hard to tell. Plastic should work fine if you have absolutely no concerns about creep or fatigue, which are only imaginary constructs artificially formulated to make MEs look almost as smart as EEs..

RE: Distressed Nerd: Alternative to thin spring steel?

Might try researching Urethane. It comes in all kinds of hardness levels from hard to really soft. I even found a website that sells urethane springs.
http://www.centuryspring.com/products/urethane.php

With a 7 inch OD and 6.9 ID one could probably smash it into a ball and have it return to it's original shape.
I'm guessing it won't perform exactly as the metal does (i.e. won't be as "snappy") but will probably be cheaper. Another design consideration, if you're concerned about imaginary constructs, is how long it will be held in the compressed state before being released. It should be cheap enough to just get a prototype made and play with it. Would also come with a ridiculous number of options for color, durometer, etc. and one could possibly have it impregnated with fibers of some sort to help achieve desired performance.

RE: Distressed Nerd: Alternative to thin spring steel?

You could use almost any elastomer.

----------------------------------------

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: Distressed Nerd: Alternative to thin spring steel?

I agree that some plastics could do this but they would probably not be remotely as stiff as doing it out of spring steel.

DistressedNerd, you mentioned you wanted it cheaper - are you aware that spring steel is actually pretty cheap stuff? Most of the time it's just high carbon steel with a heat treat. That particular arrangement might literally be straight spring steel wire passed through a loop of fabric, in which case you can literally buy meters of 0.5mm piano wire (so you don't have to organise the heat treat yourself), cut to length, feed it through and call it a day.

RE: Distressed Nerd: Alternative to thin spring steel?

Nereth1 have you watched the video? You can't scrunch 0.5 piano wire to that extent and have it spring back.

How about a thin balloon inflated to the point just before it starts to swell?

Engineering is the art of creating things you need, from things you can get.

RE: Distressed Nerd: Alternative to thin spring steel?

I had assumed that those disks literally just had spring steel inside because they give them out like candy so I assume they must be cheap - but perhaps I was wrong. Assuming they are indeed all nitinol, perhaps multiple loops of extremely thin spring steel could serve a similar function?

RE: Distressed Nerd: Alternative to thin spring steel?

Quote (DistressedNerd)

Your highness - the question was for a plastic or cheaper to manufacturer alternative to this design.

Maybe you can provide specific details of your existing spring design, such as cost, spring properties, load cycles, deflections when "crumpled", etc. so we don't have to guess at a possible solution. Since you did not provide a cost basis, how the heck would I know if Nitinol is cheaper or not?

All kidding aside, I don't think you'll find a cheaper metal alternative than common commercial spring wire alloys. As for "plastic" materials, the raw material cost of high-performance plastics is quite high. And there is also the significant non-recurring costs involved with plastic components for things like mold tooling. On the other hand, the tooling for wound steel wire springs is usually relatively cheap.

RE: Distressed Nerd: Alternative to thin spring steel?

2
Nitonol is special because it can be seemingly plastically deformed and will not spring back until a critical temperature is reached, at which point it returns to a previously set (at high temp) shape.

Sunshade disks do not use Nitonol. They don't usually use round wire either, but a flat strip of spring steel which uses the thinness of the section to produce the flexibility and the width of the strip to produce the desired loads.

Making something with decent 'spring-back' requires high elastic modulus to provide the springiness, and high strength to allow large deformations. Neither of these are characteristics of most plastics. Carbon fiber and fiberglass are suitable, except for the difficulty of joining. The spring-steel can be easily joined with a crimped sleeve and the torsion continuity is easy to maintain due to the rectangular section typically used. Without torsion continuity the strip doesn't snap back as hard.

RE: Distressed Nerd: Alternative to thin spring steel?

I feel like I need half marks for my answer. I didn't get the rectangular cross section but I got the material!

RE: Distressed Nerd: Alternative to thin spring steel?

(OP)
Agreed, Daveth it is.

RE: Distressed Nerd: Alternative to thin spring steel?

Glad to have usurped myself some glory.

But hey Daveth actually rolls of the tongue! You could really name him that!

RE: Distressed Nerd: Alternative to thin spring steel?

(OP)
3DDave - I found what you're talking about in a collapsible laundry hamper (see image), but for the life of me I can't find where to get it in varying sizes (or hardly at all) - I am looking for somewhere I can buy small quantities to test. There has to be a technical name for it or something that I am missing that's producing 0 search results.

The laundry hamper strip of steel has these dimensions rectangular cross section dimensions - 0.1'' x .025''

RE: Distressed Nerd: Alternative to thin spring steel?

If you can't find the heat treated steel off the shelf in a small quantity, it should be very cheap to get it made up at a custom spring place. The stock would presumably be available as that which is used for a flat torsion spring.

RE: Distressed Nerd: Alternative to thin spring steel?

DistressedNerd-

I wish to submit a formal objection to your publicly stated decision to rename your pet hamster 3DDave. While 3DDave did a good job of pointing out a spring design commonly used for foldable fabric sunshades (ie a C-shaped steel spring wound from rectangular section wire) that could potentially be adapted for the application in question, I did not see any evidence provided that such a spring would meet the criteria listed in the OP of being a "....cheaper to manufacturer alternative to this design - 7'' diameter circle made out of spring steel wire that easily deforms and returns to circle shape."

I, for one, do not take the bestowing of honorary titles upon members of the species Mesocricetus auratus lightly. I expect this decision process to be fair, objective and open. Obviously 3DDave is an honorable title any hamster would be proud of, as long as it was received legitimately. But if I were a pet hamster I could not imagine the mental anguish of spending the entire 24 months of my adult life suffering from the stigma that my honorary title was not legitimate. I would be ostracized by my fellow members of the rodent community, banished to undesirable sections of the Habitrail, and never again be allowed to experience the sheer joy of running on the treadmill.

Thus I respectfully request that you reconsider your decision regarding renaming your pet hamster. If you can provide evidence that 3DDave's proposal meets the criteria set forth in the OP then I will gladly withdraw my objection. If nothing else, think about the impact this decision will have on your pet hamster's future quality of life.

Best regards,
Terry

ps. You can get custom wound circular springs made from rectangular section steel wire in small quantity, and often with no tooling charges, from the Smalley Co. I have ordered prototype quantities of custom wound rectangular section wire wave springs from Smalley many times, there was no tooling charge and they were great to work with.

RE: Distressed Nerd: Alternative to thin spring steel?

Ditto Smalley, great company.

Another source for thin strips would be www.McMaster.com: 1095 spring-tempered steel:

0.015" Thick (±0.001") 1/8"W 25'L 9075K51 $28.58 100'L 9036K772 $69.28
0.020" Thick (±0.0015") 1/8"W 25'L 9075K73 31.41 100'L 9036K809 70.29
0.028" Thick (±0.0025") 1/8"W 25'L 9075K104 31.41 100'L 9036K846 71.42

RE: Distressed Nerd: Alternative to thin spring steel?

(OP)
Thanks for the referrals for where to get small quantities of wire & strip spring steel - however I was looking for a place to get real small quantities like 5 feet.

RE: Distressed Nerd: Alternative to thin spring steel?

If you want to try, McMaster would give away small as engineering sample

RE: Distressed Nerd: Alternative to thin spring steel?

Check ebay, but honestly, when someone gives you a link and part number for exactly what you asked and it's only $30, that's about as good as it gets.

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