Cannitlers, whittlers...stupid question.

[ken erickson]

This is a picture showing a catch-bit on a single spring canoe. The catch-bit is half the thickness as the backspring and the same thickness as the blade tang in this instance. This allows the blade that pivots on the other end to be full length and still clear the full width of the tang. The clearance arrow shows the difference between the size of the catch-bit and the size of the blade tang. In this picture the backspring is positioned about were it would be as if the blade was installed.. As Tony Bose and Kerry have stated , this clearance is needed to allow the backsring to rest on the blade tang and NOT the catch-bit, and to allow for any wear in the tang and spring. Of course there is a catch-bit on the opposite side frame, other end. Its hard to see the blind pin as its been peened and leveled. Second picture shows how the blade will be in the closed position(close anyways!).

I hope this helps clear up some of the "mystery" of a catch-bit!

 

[KnifeHead]

Nice images Ken...THANKS!

 

[d.parker]

This is a picture showing a catch-bit on a single spring canoe. The catch-bit is half the thickness as the backspring and the same thickness as the blade tang in this instance. This allows the blade that pivots on the other end to be full length and still clear the full width of the tang. The clearance arrow shows the difference between the size of the catch-bit and the size of the blade tang. In this picture the backspring is positioned about were it would be as if the blade was installed.. As Tony Bose and Kerry have stated , this clearance is needed to allow the backsring to rest on the blade tang and NOT the catch-bit, and to allow for any wear in the tang and spring. Of course there is a catch-bit on the opposite side frame, other end. Its hard to see the blind pin as its been peened and leveled. Second picture shows how the blade will be in the closed position(close anyways!).

I hope this helps clear up some of the "mystery" of a catch-bit!

Thanks Ken that's a great picture and explanation of a catch bit. A question if I may ask ? If a catch bit was built in the shape you have illustrated in the photo. Do you think if it was between 2 blades, like on a whittler, and as you know couldn't be blind pinned, would it touch the (walk) bottom of the springs in the closed position of the 2 rear blades ? Also would the catch bit touch the end of the back springs in the blade or blades open position ? I have a few whittler patterns with catch bits, that what I have asked happens. They all work fine, are they made incorrectly ?

 

[ken erickson]

If a catch bit was built in the shape you have illustrated in the photo. Do you think if it was between 2 blades, like on a whittler, and as you know couldn't be blind pinned, would it touch the (walk) bottom of the springs in the closed position of the 2 rear blades ? Also would the catch bit touch the end of the back springs in the blade or blades open position ? I have a few whittler patterns with catch bits, that what I have asked happens. They all work fine, are they made incorrectly ?

I have not made a slipjoint yet with a catch-bit BETWEEN two blades so I can only assume. I think that your correct in that the back of the catch-bit would or could touch the backspring and also the end of the backspring. I can envision a slight bit of pivoting action taking place, but if things are done right, very very little. I think Tony Bose made mention that if a pivot bushing was used this would serve to keep this pivot action from happening.

Ken

 

[d.parker]

Thanks Ken for your reply. In the knives I have, the catch bits pivot from .002" - 004". I can understand if Tony stakes his bushings in each back blade in a whittler that would freeze the catch bit to the bushings, and as the blades pivot on the bushing, the catch bit would not pivot. I don't know how much clearance Tony uses between walk and spring ends. Do kicks wear at a rate that it's a problem, that the back springs hang up on the catch bits, and leave a loose blade if there is a least .002"-.004" clearance between the catch bit and spring ?