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BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
Here is a drawing of an auto knife button bar.

Machinists will hate this drawing. That's OK. I hate it too. It has a couple gaps in it that would not let your precisely machine this part. If you aren't a machinist, this will work just fine. I made this so I have a future reference for an auto knife switch bar. In reality, the actual part will vary a bit but this should give you a starting point. According to Chris Crawford, the sear pin only needs about .040" to hold the kick spring so it's length will be .040" plus what ever your liner thickness is. The sear pin is hand filed. I supposed you could press fit a dowel pin but filing only a takes a few minutes.

To keep the bar level with the scale there is a couple ways to adjust it. The front notch can be filed (it will have to rest on the liner) or depending on the length of your slot, it could rest on the end of the slot in the liner also. The bar will not be automatically level with the scale. You have to have a stop somewhere on the bar.

The sear has a notch on one side for the kick spring to rest against when energized. It also has a small slant (ramp?) to lift the button over the kick spring when closing the blade.

The length of the bar and pivot position can vary quite a bit depending on how much you want the lock bar to travel.


lock bar.JPG
 

John Wilson

Well-Known Member
Here is a drawing of an auto knife button bar.

Machinists will hate this drawing. That's OK. I hate it too. It has a couple gaps in it that would not let your precisely machine this part. If you aren't a machinist, this will work just fine. I made this so I have a future reference for an auto knife switch bar. In reality, the actual part will vary a bit but this should give you a starting point. According to Chris Crawford, the sear pin only needs about .040" to hold the kick spring so it's length will be .040" plus what ever your liner thickness is. The sear pin is hand filed. I supposed you could press fit a dowel pin but filing only a takes a few minutes.

To keep the bar level with the scale there is a couple ways to adjust it. The front notch can be filed (it will have to rest on the liner) or depending on the length of your slot, it could rest on the end of the slot in the liner also. The bar will not be automatically level with the scale. You have to have a stop somewhere on the bar.

The sear has a notch on one side for the kick spring to rest against when energized. It also has a small slant (ramp?) to lift the button over the kick spring when closing the blade.

The length of the bar and pivot position can vary quite a bit depending on how much you want the lock bar to travel.


View attachment 74220

This is great. Thank you very much for sharing this.
 

John Wilson

Well-Known Member
Just finished this pair. I made one a straight back and the other has a gentle curve along the spine. I’m torn. Personally, I prefer a straight spine when I use a pocketknife but the curve is pleasing to look at.

6-1/4” overall length. Blades are 2-3/4” long. AEBL blade. Liners and bolsters are 416 SS. Scales are Desert Ironwood.

A81D5541-4339-482D-A445-D3C4B47B4E10.jpeg
 

Randy Lucius

KNIFE MAKER
Just finished this pair. I made one a straight back and the other has a gentle curve along the spine. I’m torn. Personally, I prefer a straight spine when I use a pocketknife but the curve is pleasing to look at.

6-1/4” overall length. Blades are 2-3/4” long. AEBL blade. Liners and bolsters are 416 SS. Scales are Desert Ironwood.

View attachment 74235
Very beautiful work John! I’m partial to the one on the bottom. If you’re giving lessons I’ll sign up! Seriously those are some awesome knives.
 

Sean Jones

Well-Known Member
Just finished this pair. I made one a straight back and the other has a gentle curve along the spine. I’m torn. Personally, I prefer a straight spine when I use a pocketknife but the curve is pleasing to look at.

6-1/4” overall length. Blades are 2-3/4” long. AEBL blade. Liners and bolsters are 416 SS. Scales are Desert Ironwood.

View attachment 74235
Beautiful work John! I like both of them equally well.
 

John Wilson

Well-Known Member
thanks guys. I’m still in the process of failing my way to success. I’ve made a handful of folders up til now, but i’m currently working through 8 in a row. It’s been a good opportunity to improve my process and to be able to anticipate the bug-a-boos before they happen rather than constantly fixing them after the fact.
 

Sean Jones

Well-Known Member
Finally got these five in AEB-L ready to go out for heat treat.
 
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