Help with my first frame lock design and production.

H

Honzis

Joined
Jan 12, 2018
Messages
48
Hello folks,

I'm creating this thread since I will probably need to ask some questions now and then. Also could be interesting to document the progress of my work and motivate me to finish this.

I'm slowly (as I'm progressing with my CAD skills) refining the design of my first frame lock.

I want to do first prototype with a blade from N690 steel, presentation side scale from 4mm thick carbon, frame lock side scale from some spring steel since its just first prototype and I don't want to use titanium yet. The knife will use bronze washers and will be cut from the slabs using water jet (to ensure better accuracy that I would achieve with using just my hand, also I lack any propper tooling) from which I will continue to build the final knife. Also, I want to use my 3D printer for the basic alignment, mechanical and ergonomic issues prevention which should help me to get the first steel product hopefully minimize any design issues that otherwise would emerge.

and the first question is:

Q1) Can I use the N695 steel for frame lock? I know that 4mm is too thick so I will have a friend that has a mill/lathe at work to remove some material. If I can use the N695 for frame lock, how much should I mill out from the bend location and is the best hardness to heat treat it to.

Thanks and have a nice day :)
 
When I heat treat lock springs for customers thy are in the 45-50rc area; But most common seams to be 47-48rc. If your wanting to take the thickness down on the blade and spring it’s best to surface grind both of them together as a matched set so everything is the same. From there you can tweak The walk and talk of the action much easier so everything is crisp and smooth.

I don’t make folders I just have heat treated and surface ground a bunch for customers.
 
JTknives said:
When I heat treat lock springs for customers thy are in the 45-50rc area; But most common seams to be 47-48rc. If your wanting to take the thickness down on the blade and spring it’s best to surface grind both of them together as a matched set so everything is the same. From there you can tweak The walk and talk of the action much easier so everything is crisp and smooth.

I don’t make folders I just have heat treated and surface ground a bunch for customers.
Click to expand...

he’s talking about a frame lock. Not a slip joint.


Yes you can use steel but it will be heavy.
 
Facepalm lol.

on another note how is thin Titanimum cheeper then blade steel that you have to Spend time to mill down. Look on eBay and pay a few bucks to get some small chunks.
 
Yeah I would def get titanium... It's pretty cheap when you factor in hear treat and shipping costs (unless you do it yourself). For a proto I would build a liner lock as you can use really thin (.060") titanium which is cheap
 
Honzis said:
Hello folks,

I'm creating this thread since I will probably need to ask some questions now and then. Also could be interesting to document the progress of my work and motivate me to finish this.

I'm slowly (as I'm progressing with my CAD skills) refining the design of my first frame lock.

I want to do first prototype with a blade from N690 steel, presentation side scale from 4mm thick carbon, frame lock side scale from some spring steel since its just first prototype and I don't want to use titanium yet. The knife will use bronze washers and will be cut from the slabs using water jet (to ensure better accuracy that I would achieve with using just my hand, also I lack any propper tooling) from which I will continue to build the final knife. Also, I want to use my 3D printer for the basic alignment, mechanical and ergonomic issues prevention which should help me to get the first steel product hopefully minimize any design issues that otherwise would emerge.

and the first question is:

Q1) Can I use the N695 steel for frame lock? I know that 4mm is too thick so I will have a friend that has a mill/lathe at work to remove some material. If I can use the N695 for frame lock, how much should I mill out from the bend location and is the best hardness to heat treat it to.

Thanks and have a nice day :)
Click to expand...
So you will cut on water jet 0.02 -.01 bronze washers....Good luck with that :thumbsup: Phosphorous-bronze pivot washers cost 0.5 $ ..............:)
How anyone can know how much should you mill out from the bend location on N695 Steel ? You will need to find that yourself my friend. It depends how long is cut frame lock part and depend from hardness/springiness .
Good luck with project .My advice is you don t need to manufacture every part , sometimes it is cheaper to buy some parts :thumbsup:
 
razor-edge-knives said:
Yeah I would def get titanium... It's pretty cheap when you factor in hear treat and shipping costs (unless you do it yourself). For a proto I would build a liner lock as you can use really thin (.060") titanium which is cheap
Click to expand...

I know that steel is heavy but I like the look of frame lock, and since it will be just working protype I rather pay the price in weight and have shape and ergo prepared when I switch to titanium.

Natlek said:
So you will cut on water jet 0.02 -.01 bronze washers....Good luck with that :thumbsup: Phosphorous-bronze pivot washers cost 0.5 $ ..............:)
How anyone can know how much should you mill out from the bend location on N695 Steel ? You will need to find that yourself my friend. It depends how long is cut frame lock part and depend from hardness/springiness .
Good luck with project .My advice is you don t need to manufacture every part , sometimes it is cheaper to buy some parts :thumbsup:
Click to expand...

Already ordered pivot, thumb stud and some other hardware from the internet, I will just water cut the scales and blade stock.
 
UPDATE #1

I finally managed to learn basic functions in Freecad so here is the first rough draft of the model with working pivot/blade/stop pin placement, everything else will be changed as I progress with the design. It's obvious that I used my favourite knives that I have at disposal for reference but from this point forward, I want to tune the design to be more and more original yet still practical.

prototype.gif
 
On your cut out I would do radius corners. Sharp corners are great places to build up stress. That’s why thy call them stress risers. Do it something like this.

Photo%20Dec%2015%2C%2010%2034%2024%20AM.jpg
 
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JTknives said:
On your cut out I would do radius corners. Sharp corners are great places to build up stress. That’s why thy call them stress risers. Do it something like this.
Click to expand...
Thanks, definitely going to do round corners everywhere!
 
Proceeding faster than I expected, but here is the second prototype that locks up and considering that it's made from plastic with horrible tolerances all around, it actually feels good.

 
3d printing is so cool, I do it on every knife I make!
 
I do it the same way you do... Make the cad file, print, make adjustments, reprint if needed :) not much to it!
 
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