Level 10 spring differences and changes in restance

[QUINCYMASSGUY]

I was wondering if someone who knew physics, etc, could explain to me the difference in effect a shorter, but more closely coiled spring would have compared to a longer but more loosely coiled spring would have? In the assumption their initial pressure is the same (1lb for example) would the amount of force they are applying be the same when both are compressed to the same length? what about if they were both compressed just 1 inch?

This relates to the smaller level 10 spring and the first larger one: The larger obviously applies more pressure but is this entirely related to the fact the spring is lengthened out? What about when they are compressed to the point of the bolt being fully forward, did both springs increase resistance at a relative rate?

And to finish up: what was the reason AGD chose to have one smaller spring (although making it match the original spring is probably involved) and what made them change to the longer, looser springs we find in the Lvl 10 kit?

[xatle]

http://www.machinedesign.com/asp/viewSelectedArticle.asp?strArticleId=55984&strSite=MDSite

this is an article from the july '03 issue of machine design.
it has alot of stuff ill probably never really need to know about springs in it, hope it helps.

[QUINCYMASSGUY]

excellent

hahahaha.... I think I should have taken more physics, but that should help. I think my key question is what makes a spring have a more consistent pressure as it gets compressed, width or a certain spacing of the coils?

[bjjb99]

A compression spring's "springy-ness" is quantified by its spring constant--the amount of force required to compress the spring by some fixed amount.

The spring constant is related to the type of material the spring is made of, how big the wire is making up the spring, the diameter of the spring itself, and the number of spring coils which actively participate in compression.

The material is important since some metals are more rigid than others. The modulus of rigidity is what you're looking for here... a high rigidity means a stronger spring (higher spring constant), all other factors being equal.

The wire thickness is important since a thicker wire is more rigid than a thinner wire of the same material... there's just more stuff that has to bend/flex. A bigger wire diameter means a stronger spring.

The spring diameter is important because it determines how much flex a given section of wire making up the spring has to undergo during compression. If you mentally unwind a spring into a straight wire and try to bend it (that's essentially what compressing a spring is doing), then a short piece of wire (a small diameter spring) will take more force to bend through the same distance. Large diameter springs mean lower spring constancts, and thus a softer spring.

The number of spring coils that participate in compression also works in tandem with the spring diameter. More coils means a softer spring since you're not flexing the metal as much per unit length.

Hope that helps... here's a spring constant calculator webpage for ya if you're interested.

http://www.engineersedge.com/spring_comp_calc_k.htm

BJJB