School Me About Springs.

[airnutz]

Hello folks!
After a lot of dwelling and searching here, I have run across "Vortek this, and Vortek that".  I understand that better and more efficient spring control is essential for more comfortable and reliable shooting.

In my old Diana 35 is a strong spring that has a definite curve, but still seems to have good power.  I have at hand a spring that is supposedly more powerful (new item), about four inches longer, but four coils less.  I measured with simple calipers and the od is the same.

1.  How much should old springs show to have been compressed through years of use, meaning how much shorter are they now, as opposed to brand new?

2.  Will a much longer spring, with less coils have more energy than the old brute that is now in use?

3.  In the spring related info here in The Library, the sizes read to me like something alien.  .409, or .417 whatever....are these "inch" measurements?  How are these numbers even measured?

4.  Give me metric, or give me headaches!   

Please, I just am a new dude with a real old gun, and I like the atmosphere here, and would ask kindly for general or even exact info on springs.

Thanks in advance.

[JimL911]

Your new spring may be longer because it has not been set. JM sells springs unset as well as set.
If you install an unset spring it will be more difficult, but once you cock the gun it will set itself to a working length. Spring dimensions are usually stated in inches, coil count and inside dimension.
33X.128-.562IDX12.5 long as an example is a 12.5 inch spring with 33 coils of .128 inch thick wire with an inside diameter of .562 inches.
In metric 31.75 cm long X 33 coils of  3.2512 mm thick wire with an inside diameter of 14.2748 mm.

As for loss of length there is no set amount, it all depends on how long between changes, how much it is shot, and how much loss of power is acceptable to you.
For the average person the spring will be acceptable for a few years whereas a person who shoots FT would go through a few springs in a year.

[airnutz]

Thanks JimL.  So if I measure the old spring, then the new one that has been set once, and the newer one has a higher number after multiplying and subtracting with this formula, then the higher number has more strength.

OK.  (Coils x Wire Diameter) minus (Coil ID x Overall Length) = what?

Is this just an overall "strength" equation, like a rule of thumb, or for a comparison of two different springs?

Am I missing something?

[airnutz]

To set the spring, should the gun be cocked also?

Is just installation of the new spring enough to set it properly, or should the gun be cocked also to measure properly?

[Mark 611]

once you install an un set spring as soon as you cock it it will take set and after a few shots it will feel like normal again, I just got done installing a spring from Vortek that I had to do all if the finish work on because I got a spring that was cut right off the machine un set and un finished ends and no I didn't set it prior to the install because it was shorter than factory length and had very little pre load so I didn't see the need to to set it,  and also an un set spring my be harder to install on the guide as this one was I had to pound it down on the guide and it is very tight but it should loosen up as the spring takes it set and it was hard to cock on the the first pull of the lever but after that it cocked just like normal and functions as it should! and its smooth as butter and no noise and shoots like a ram just a thunk at the end of the shot cycle and as it breaks in it will only get better so far the chrony #'s are very consistant the ES is less than 10fps with less than 60 shots thru it, just my 2ct

[airnutz]

Thanks Mark611.

I understand now the spring is set after a couple of cocking routines.

I am now with the formula, still trying to figure it out.

I have the measurements of the new spring, the old one i can guesstimate, as only the length is different, the number of coils I already know.

[Mark 611]

what are trying to figure out exactly?

[airnutz]

what are trying to figure out exactly?

1.  The current spring is 25 yrs. old. and bent up. (see pic above).  The gun shoots still nicely.
2.  The new spring is supposedly for my Diana 35 very strong. It is longer, but has less coils.
3.  Can the new spring efficiency be measured?  I do not have a Chrono to test. 
4.  I would like general spring info.

Thanks Mark for your interest.

[Rcoolbaugh]

I don't believe it's a formula, it is the format for how springs are specified.

[airnutz]

I don't believe it's a formula, it is the format for how springs are specified.

Exactly.
I need to specify if the new spring (yet un-set) will be stronger than that which I have.

[Mark 611]

 well I'm not an expert on this at all but I can make a pretty educated guess {SWAG} LOL!!!! Measure your wire size from the stock spring and then the spring you want to use then the length, don't forget spring wire technology has come along way from 25yrs ago with different mixes of metal used in the process, you'll see in some spring kits out there that the spring used in the kit is sometimes allot shorter than the factory spring, and that is done for several reasons, either a different wire size is used or the newer metals in the metal being used in to days spring wire, their are some general rules of thumb here springs can be designed for a specific use you need to see what the intended use for that spring is and it will give you a guide line on what to expect from that spring but their are other variables involved such as guide to spring fit piston seal fit, proper lubing {etc} what looks good on paper doesn't always work like its suppose to! I'm sure theirs a formula to figure out what the spring should do but I don't know what that is because I'm not that deep into tuning I base my spring/kit buying off of what others before me have tried and trued or I just experiment {SWAG it} until I find what I'm looking for in a spring by wire size, length, stack height, fit or spacing theirs so many ways to do tuning work to an AG, and once I find what works best for what I intend to use the gun for I stick with that set up for that gun! just remember you can stick the same spring/kit set up in 2 different guns and get 2 completely different out comes, thats why its called tuning! JMHO

[Mark 611]

also set or un set makes no difference in power! it just means the spring is either ready to install or its not basically

[airnutz]

Hmmm....

Ok.  I think what I will do is wait until the new breech seal is installed, then check the "punch power" that comes about.  I will check out real closely Grandma's cherry tree (it is her gun, she hated crows in her tree) and see if the power is still there.

....and then, get rid of the old stuff anyway, disassemble, measure, install the new stuff, re-check and measure, and probably LMBO at how strong the old girl can really shoot!

Thanks guys, I will report. 

[Pete]

So yer want to know if the new spring will fit in the gun ? "right"
as long as the new springs OD fits in side the piston & the ID fits
over the guides...yer good to go...

To work out the stack height " compressed length"
On the old spring measure the wire thickness..
IE.. wire thickness X number of coils = "A"
same on the new spring.. As long as "A" on the new spring
is no more than "A" on the old spring it will fit when compressed..

[airnutz]

To work out the stack height " compressed length"
On the old spring measure the wire thickness..
IE.. wire thickness X number of coils = "A"
same on the new spring.. As long as "A" on the new spring
is no more than "A" on the old spring it will fit when compressed..

And the length  difference between the two?

[Pete]

To work out the stack height " compressed length"
On the old spring measure the wire thickness..
IE.. wire thickness X number of coils = "A"
same on the new spring.. As long as "A" on the new spring
is no more than "A" on the old spring it will fit when compressed..

And the length  difference between the two?

If theres a diffrents in the uncompressed length... its either that its unset
or the wined rate... either way don't worry about it... All it means is there will be more pre load on the spring...
if its unset it will set its self in the gun after cocking...
if its the wined rate , will give more pre-load so the starting force
will be higher before cocking "more power"

[airnutz]

I've really studied the Library.  On Charlie's  "Calculating Spring Spacing" chart, item A, he talks about measuring with the piston in it's Latched back position.

What does this mean?  Does it mean when the gun is cocked?  I understand where and how to measure the chamber space, just not the terminology here.

Anyone?

[Mark 611]

ya that means that's as far back as the piston will travel and that measurement will give you your max stack height on your spring/spacing combo or just spring room that you cannot exceed!

[airnutz]

Thanks Mark!

I think I have it now, finally!

As soon as I install the new leather o-ring and check velocity differences, I will get at the spring.  This time, I am happy with the help from you guys and this site, to know ahead of time if it will work.

Thanks to all.

PS:  Uhhh, I think I may just like tinkering with the old gun!  I am considering a new bluing and reworking the wood.