Need deminsions on Crosman springs.

[Rescue35]

Hammer springs for the Disco and 2260.

Diameter, length, wire size, active coils, or whatever info you can give me. Much appreciated.

[rsterne]

2240/50/60: Length = 2.00", Outside Diameter = 0.286", Wire = 0.030", Coils = 15.5

1377/2289: Length = 2.03", Outside Diameter = 0.296", Wire = 0.033", Coils = 20.5

Disco: Length = 1.94", Outside Diameter = 0.291", Wire = 0.035", Coils = 14.5

Trakar # C0762-102-0445: Length = 1.76", OD = 0.305", Wire = 0.040", Coils = 15

The springs above are listed in the order of stiffness, from weakest to stiffest.... There is a 2.0" long Trakar spring with 18 coils but the 1.75" one is stiffer and has a greater range of adjustability using an RVA.... Note that the wire size is the governing factor in spring stiffness.... They will all fit in the 22XX / 13XX / Disco platforms....

Bob

[lloyd-ss]

Holy Cow Bob,  you are THE reference source.  No joke!

You might already have a favorite "spring calculator" site, but for doing "what-ifs", I like this one:

http://www.msdspring.com/SpringCalculator%5CDefault.asp

For Bellville springs, I have a download of this calculator. 

http://www.mubeadiscsprings.com/english/download/calculation_program.html

Lloyd

[rsterne]

I love the Trakar Springs catalogue.... all the info on every spring they make, rate, length, diam, max deflection, max load.... including bellevilles....

http://www.trakar.com/

Bob

[Rocker1]

 You  2 guys are so far over my head  its unreal, hoping one day this will all come to me and make good sense  lol!!!! Thanks David

[Rescue35]

Thanks Bob!

Time to go make a mandrel.

The "Machinist Handbook is a treasure trove but there is a lot of info on spring design on the web. Such as...
http://home.earthlink.net/~bazillion/design.html

Probable the easiest to use. They are in chart form and easy to use once you get the hang of it. Originally an article in "Projects in Metal" magazine in the 80s. "Home Shop Machinist" and "Machinist Work Shop" have replaced it and both are good publications geared mostly toward the hobbyist.
http://www.oldengine.org/members/holland/images/makingsprings/thumbnails.html

[rsterne]

I've made a few simple compression springs by hand.... nothing more than a common nail held in a vice and a length of music wire of the correct diameter.... Clamp one end of the wire in the vice with the nail, and wind the coils close together (like a tension spring).... then stretch the spring out overlength and then "set" it by compressing fully (on a guide) and releasing.... Lastly I cut it to length and tweak the ends by hand.... It takes a bit of time to get the proper diameter mandrel (nail) if the diameter of the spring is critical.... but the repeatability is quite amazing for a hand made spring.... 

Bob

[lloyd-ss]

Hey Rescue and Bob,
I have never tried winding my own springs , but sounds like it just takes some practice. 

Probably easiest to rig the mandrel so that it can be manually turned and the music wire fed into it?

Thanks,
Lloyd

[Toolmaker]

Probably easiest to rig the mandrel so that it can be manually turned and the music wire fed into it?

Thanks,
Lloyd

 I've had good results holding the mandrel in a lathe and turning the headstock by hand while feeding the music wire.

[lloyd-ss]

Probably easiest to rig the mandrel so that it can be manually turned and the music wire fed into it?

Thanks,
Lloyd

 I've had good results holding the mandrel in a lathe and turning the headstock by hand while feeding the music wire.

Sounds good.
I guess there is quite a bit of spring back.  HeHe, bad pun intended.

Anybody have a  good source for small rolls of music wire?

Thanks,
Lloyd

[Rescue35]

I get my music wire from Enco www.use-enco.com $9/lb and you get a lot of wire in a pound roll.
ETA they also have pre cut 12" lengths in certain wire sizes/various quantity

WARNING! SPRING WIRE CAN BE DANGEROUS. USE PROPER SAFETY PRECAUTIONS.

I set my lathe up with the mandrel chucked and supported by the tailstock. There is a wire feed device in the tool holder (scrap metal with a hole drilled to line up w/ mandrel). Set the change gears like you would to thread. ie A 2" spring with 16 active coils = 16/2 = 8 coils per inch. Set the lathe to 8 TPI

Turn it by hand a couple of times to get your closed (touching) coils and then run the lathe slow and engage the carriage feed (you could do this by hand also). It will lay the wire down with the correct pitch. Keep hand tenscion on the wire as it feeds.

Yes you have to deal with spring back. It varies with wire size.

All of this I picked up from the links I posted above (especially the oldengine one) and of course trial and error. It sure beats waiting for UPS to deliver a $.50 spring when I can make one in a few minutes.

[lloyd-ss]

Of course... set it up for threading...duh.  That clinches it.  Gotta give it a try!
Thanks again,
Lloyd

[Mark5043]

2240/50/60: Length = 2.00", Outside Diameter = 0.286", Wire = 0.030", Coils = 15.5

1377/2289: Length = 2.03", Outside Diameter = 0.296", Wire = 0.033", Coils = 20.5

Disco: Length = 1.94", Outside Diameter = 0.291", Wire = 0.035", Coils = 14.5

Trakar # C0762-102-0445: Length = 1.76", OD = 0.305", Wire = 0.040", Coils = 15

The springs above are listed in the order of stiffness, from weakest to stiffest.... There is a 2.0" long Trakar spring with 18 coils but the 1.75" one is stiffer and has a greater range of adjustability using an RVA.... Note that the wire size is the governing factor in spring stiffness.... They will all fit in the 22XX / 13XX / Disco platforms....

Bob

Bob...thanks so much for breaking it down in such detail.This is exactly what I've been looking for.
Great thread!I'll be sure to put this info in my notes for future builds...