In my first post on this thread I did link a site that discussed the differences between a dual-rate spring and a progressive spring.

The picture of the spring you posted is progressive but it is also using more than one parameter adjustment to make it progressive. I suspected the spring also tapered so that when it was compressed the solid height of the spring would be shorter and after doing a quick google search of "progressive spring", I found the picture you posted and the website it references to and it says "The end coils are designed to compress without coil-to-coil contact so these springs are extremely compact and completely noiseless in operation." [http://www.gknservice.com/global/pas.../springs.html]

You can create a progressive spring by changing the number of coils in a spring and how they are spaced relative to each other. You can also make a progressive spring by having it taper on the ends, or you can also change the wire diameter through the spring (however, this is the most expensive way)

Attached is a spring chart that shows a variety of different progressive springs.

In the RC world there are a several companies that have made progressive springs like Traxxas (increased number of coils at the ends), and Schumacher BB springs (Taper in at the end).

You forgot to quote that last lil bit. This thread was created (you quoted me in the opening post) because i specified and said 'ONLY' (to another member) in a generalized explanation referencing rate change through wire size... and now youre going to leave out pertinent information?


Are the springs on either the B4 or T4 of this type...?

I understand we are referencing other companies springs as well but... how does this relate to AE springs...?

Sorry if I left out something in one of your qoutes, many of them are really long and i was just doing might best to make it concise and clear what I was addressing.

The current line of AE 1/10 scale off-road springs are all 'linear'. The active coils are all equally spaced.

Its funny you say that (as a general statement), because a professor would raise is eyebrow to that and then ignore you. lol

One of the things that frustrated me so much was reliance on equations. Everything had to have an equation to verify the result. I understand their purpose... but it doesnt mean i have to like them.

Im an on hands kind of person, definitely think outside the box, and often took what was in a textbook as a guideline... and not the answer.

IMO... theory is just that... THEORY. If we never look past current theory and press for a deeper understanding... will we ever further develop?

Questions formed theory, so theory should forever be questioned.

Well, then, maybe theory isn't the best choice of words in this instance. Statement of opinion maybe?

I am a hands on person myself. Many of my close friends are practicing mechanical engineers... I am a professional car builder. Performance and race cars mostly. I have a welding and materials background as well as mechanical. Through MUCH trial and error and a lot of common sense I have come to my I guess opinions. I will admit and will likely get flamed for admitting, I couldn't work out in a mathematical equation why something works or doesn't... I can however build and test something to prove it fairly quickly with the desired results for proof of concept .

As for the existing topic... It may be over simplified... but I was once told MANY years ago a coil spring can be likened to in its most simplified terms to a straight rod spring. In that the longer it is the easier it is to bend in a given O.D. That being the case in a given free length the more coils the longer that material had to be to make said coils bend... Softer. In a coil spring that has progressively more coils somewhere in it's winding it will act progressively. Simple enough concept to me... but, again I can't supply an equation and for that I apologize in advance