spring problem

SVanderkolff

SVanderkolff

Joined
Oct 31, 2002
Messages
979
I am attempting to install the torsion spring in an automatic. I am using a 1/2" od spring from knifekits, I am not sure which strength. The problem is that when I attempt to load the spring, that is take the blade of the knife from the open position to the closed the spring deforms. It seems to have only about 90 degree travel before deforming. Obviosly I am doing something wrong but I am not sure what.
Thanks
Steve
 
Offhand I'm guessing you're using the wrong spring for your application, or you need to change the anchor point so the spring doesn't need to compess more than the 90 deg you mentioned...but the truth is I don't know what I'm talking about, and frankly I shouldn't even be replying to this. I just can't help myself. Looking forward to what people say who actually know what they're talking about. BTW Steve, I checked out your website- very beautiful knives!
 
Sounds like you are turning the spring the wrong direction. It should be getting tighter ( smaller) when closed, and larger when released. If you turn it the other way ( expand it to close) the spring will deform.
 
I think I may have figured out the problem. I checked first to make sure I was torqueing inthe right direction, thanks Stacey. But I was. I thought maybe I did not have enough room in the groove for the spring so Imade it a bit deeper in bohthe blade and the liner but that did not work either. This is getting expensive in springs. Looked at it some more and wondered. The groove that I have cut for the spring is just that a groove, both in the blade and the liner. In niether case have I gone all the way through so in effect I have a trench that is the exact size of the spring,therefore there is no room to the inside of the spring for it to contract. Does that make sense, do I need to broach out the centre completely in order to allow the spring to contract?
Thanks
Steve
 
SVanderkolff said:
I think I may have figured out the problem. I checked first to make sure I was torqueing inthe right direction, thanks Stacey. But I was. I thought maybe I did not have enough room in the groove for the spring so Imade it a bit deeper in bohthe blade and the liner but that did not work either. This is getting expensive in springs. Looked at it some more and wondered. The groove that I have cut for the spring is just that a groove, both in the blade and the liner. In niether case have I gone all the way through so in effect I have a trench that is the exact size of the spring,therefore there is no room to the inside of the spring for it to contract. Does that make sense, do I need to broach out the centre completely in order to allow the spring to contract?
Thanks
Steve
Click to expand...

The spring diameter does decrease as you close the knife. If you take out all the center then it will try and take a "shortcut" across the center and deform permantly. You have to have a large enough cut out for the spring to go from full open to full closed. When I make an auto I take out all the center in the spring recess and then make a bushing that only lets the handles tighten to a certain point. It also acts as a post for the spring to wind around while closing. Hope this makes sense.
 
Gave it a try. What I did was use the smaller broaching cutter to make the groove for the spring wider. Once that was done it worked like a charm.
Thanks again for all the help.
Steve
 
I do not know what type of cutter you are using, If it does not cut a flat bottom hole then as the spring tightens and gets smaller it will tend to ride up the uneven bottom. As the spring tightens it not only gets smaller in diam. it grows in length. Sometimes the uneven bottom will make you run out of room for the extra length if you have not allowed for it, making the knife not want to close properly.
 
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