Slipjoint template question

[Sean Yaw]

I am thinking about making a wharncliffe swayback slipjoint and found the following patter from Chris Crawford's repository:
https://chriscrawfordknives.com/fil...rns/2.75_Inch_Swayback_Jack_-_Raymon_Hunt.jpg

According to my (tenuous) understanding of slipjoints and physics, it is not a good idea to cut out a pattern for a spring that is under tension. The images in this pattern all show the spring under tension. Does anyone have any recommendations for how I should modify my tracing from these images to account for this concern? One thought was to just use it as is and put in the tension when I drill the final hole in the liners, but that would change the shape of the handle, so I am looking for a better solution from wiser people. Another solution is to just use a tried and true wharncliffe pattern (a la Tony Bose) and modify it to be a swayback. That is probably not a bad solution.

 

[wkfl]

I got no clue to tell you the truth but I’ll take a stab at it. I would make a template as is, use the template and draw from the center pin back as is; then drop the tang end say 3/32 or so, trace it and blend it back to the center pin, leaving some extra meat to blend it to the blade. Good question for sure.

 

[Sean Yaw]

Micheal, That seems like a logical course of action. Thanks.

 

[Hengelo_77]

Good looking template I might give I a go as well.

The spring will pivot on the middle hole and you'll lower the spring app. 1/8" at the tang side.
So leave a bit of material on the up side of the spring at the tang side and the bottom side at the back side.
Your spring will be softer then the blade, you'll be able to work it post HT

 

[AVigil]

Extend the spring tip down .030"

That will give you enough meat to work with and be sure to leave some material on the top of the spring above the liners, then you can grind down to the top of the spine and it will all work out.