coil springs

RedFury

RedFury

Joined
Jun 17, 2015
Messages
325
Good evening. I'm being stumped by a silly little thing. I have a cheap made-in-China automatic. It's a scale release. I carry and use it a lot because I never lose cheap knives and it's fun to hand it to other people and watch them try to figure out how to open it. I have run this darn thing thru thousands of open and close cycles. I even had to switch off to another auto for a while because the action of opening it started to make some arthritis flare up in my thumb joint.
Anyway, the coil spring in it broke a couple of days ago. It's a very simple knife and I had some springs in my bench drawer. Should be a no-brainer to drop in a new spring? Nope. I have now tried 4 different springs that look to me to be like the original but they all jump out of the hole in the blade before I can get it all the way closed. The springs I have tried have been of different degrees of "power" but they all jump out. The hole in the blade seems a good bit oversized but it was oversized for the original as well.

What am I missing?

Thanks
 
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[/IMG] Im sure you know how challenging it is for those of us born before 1950 to upload a photo? I will try
 
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OK looks like I got an image to load. Only took about two hours from phone to computer to photo bucket to Blade Forums. Simple.
The spring on the left is the original. I lost the other half of it but it looked the same. It broke at about the midpoint.
 
You're clocking the spring so the preload is in the right direction?
 
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As I wind the blade counter clockwise to build tension I can get about 90 degrees further before the tail of the spring snaps out of the hole in the blade. One spring stayed in but deformed before getting the blade all the way to the closed position.
 
kuraki said:
You're clocking the spring so the preload is in the right direction?[/QUOT

Can't see any other way to wind it. The edge has to be in when closed and it turns clockwise as it opens. Spring has to propel it through 180 degrees of rotation and still keep pressure on it when it hits the lock. I just feel like I'm missing something incredibly simple and obvious.
Click to expand...
 
Ok, i think i understand the problem. The tang will keep the tail of the spring trapped once the blade is in the open or closed position, but where it is now the notch in the tang lets the spring pop out. Is it possible to grow a third hand to hold the spring tail down with a screw driver or something while you rotate the blade?
 

Just checking. I'm no good at unwrapping things like springs or rope in my head have to have hands on it.
 
diamond file the outside of the spring hole edge so that it angles back toward the round end of the blade. Bend your spring end past 90 degrees so that it is positively captured and fits in your angle you just filed. It looks like your blade is rotated too far for putting preload on it, that's why your other spring deformed.. Maybe shoot for fully relaxed spring at a little over 180 degrees handle to blade fully open.
 
What model knife are you putting the spring in? Are you buying springs that are compatible with that knife? I may be wrong, but it looks like your springs need the hole in the blade to be 180 degrees (give or take) from where it currently is. Do you still have the broken spring?
 
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