View Single Post
Old January 4th, 2008, 18:06   #9
ChiefInTrees
 
ChiefInTrees's Avatar
 
Join Date: Dec 2007
Quote:
Originally Posted by Flatlander View Post
Danke, Saint: I'm not saying you guys are wrong, but could you state where you get your information from or how you know? I'm trying to work out the forces the spring undergoes in my head and I believe there to be mainly two - bending and axial.

How I see things happening:
-The coils act like mini 'levers' of sorts causing bending moments on these 'levers' - main cause of the spring length change.
-Stretch out the spring into a straight wire and picture an axial force on wire. This will cause it to shrink. Now when this wire is wound into a spring the shrinkage would cause the spring to rotate during compression/decompression. I can't see this axial force/strain being great enough to really have a noticable effect.

A simple definitive test would be to chrono a gun with a bearing spring guide. Replace the spring guide with a non-bearing one but add spacers so the overall thickness is the same and compare the chorno results. Anyone ever done this?
These are not car springs.
Irregular pitched springs have a great deal of rotation. You don't need a textbook, you just pickup an airsoft spring, put it on a rod with a bearing at the bottom, and put a bearing above it. Mark the bearings and compress it and watch the bearings move.
It also removes tension and gives the spring a straight push instead of more force on one tiny spot. Less tension during expansion means faster expansion, means more compresses per min.
__________________
There are no such things as dead bodies. There are only zombies who are too afraid of Bruce Campbell to get up.
ChiefInTrees is offline   Reply With Quote