GTA
All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Topic started by: Pete on September 06, 2010, 01:04:01 AM
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Hi...
Heres something to take into consideration when
choosing a replacement spring for your gun...
I have been on the phone with a out fit that makes springs
wanted to have my own made...easy they say...but they don't
carry the wire that works at the right frequency...silicone base wire"
Any way while talking with them...the guy said the more coils a spring
has the less the twist it produces will be...because theres more coils each coil
compresses less so it wants to unwind less..the further a coil moves the more it unwineds...
Intresting bit of info....
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Good info Pete.......kind of makes sense after readfing it. So using a shorter spring and spacers should help with the twist?
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Good info Pete.......kind of makes sense after readfing it. So using a shorter spring and spacers should help with the twist?
From what Pete said, a longer spring will have less twist.
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My loose interpretation....
Springs with a Higher coil count per inch = less twist
Springs with a Lower coil count per inch = more twist
Pete, I hope you find a good source for springs.
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OK...Got it now.
That's why I'm not a tuner........just a parts changer. lol
I have to have the smart guys figure out what I need, then I can just swap out the parts. lol
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Hey Pete, I'm sure you can decipher all the jibberish in this article? What a nightmare. lol
http://www.brighthub.com/engineering/mechanical/articles/77477.aspx (http://www.brighthub.com/engineering/mechanical/articles/77477.aspx)
•Finding the mean diameter (D) of the spring and the spring wire diameter(d):
The mean diameter of the spring (D) = inside diameter of spring + diameter of the spring wire = 25 + d
By using the eqn.3 we got:
T = (Π Smax d3 )/16
Or, 400(25+d)/2 = (Π Smax d3 )/16
Or, 200(25+d) = (Π * 400 * d3 )/16
Or, d = 4.2 mm
So, the spring index C = D/d = (25+d)/d = 6.6
And, the value of K = 1.227
Now, you have to use this C value in eqn.1:
400 = (8 * 1.227 * 400 * 6.6)/ (3.14* d2 )
Or, d = 4.54 mm
Ok, my head just exploded. ??? ???
Good lord, there are so many variables and so much math.
I'm just a parts changer too deanda.
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Jeeeeez..........you just took all the fun out of air gunnin!
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That article has alot of good info on there.. Thats if you wanna take the the time to run all the numbers...
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LOL!!! makes my head hurt. Thanks David