IKBS drill bit.

[DOAlaboratories]

i'm currently in the process of making a balisong, so i ordered the specialty IKBS drill bit from tracy. it's a 3/8" counterbore with a 3/16" pilot. i'm using 3/16" pivots, and when i made the race, it was double the size i needed. did i get the wrong size counterbore? if so, i'm in trouble. where could i get one with a 5/16" counterbore?

or did i do it right? i'm horribly confused, so any help here is appreciated.

 

[Fellhoelter]

5/16 is the size you need if you are using 1/16" balls like most of us.

Now you need some 3/32" balls.

McMaster sells them. Part # 9528K34

 

[kyle1058]

I don't mean to resurrect an old thread, but I want to do some IKBS retrofits on a few of my knives. I ordered some 1/16" ball bearings. I would like to order a drill bit that's been ground for this if anyone knows where I can order one?

I do have access to CNC mills if i have to, maybe use a ball nose end mill and make a circle into the knife around the pivot pin hole? I have no idea how big it should be? Thank you! -Kyle

 

[Fellhoelter]

8mm is the magic number for a 3/16 pivot, you don't mention your pivot diameter. (It's a couple of thousandths bigger than 5/16" giving your balls a little "breathing room". It's like boxer shorts, for IKBS....)

You can plunge with an end mill, interpolate with a smaller endmill, or use a counterbore.

 

[kyle1058]

8mm is the magic number for a 3/16 pivot, you don't mention your pivot diameter. (It's a couple of thousandths bigger than 5/16" giving your balls a little "breathing room". It's like boxer shorts, for IKBS....)

You can plunge with an end mill, interpolate with a smaller endmill, or use a counterbore.

Oh, you're actually talking about putting a flat counter-bored surface as a bearing race.. In my mind i was thinking milling into the handle with a ball end mill (interpolated) to make a channel for the bearings but you would use the outer part of the counter-bore and the pivot pin for the inner wall to contain them...

I'm going to assume the knives I want to convert are different sized pivot pins, but i don't have much for tools here at my house to take apart things or measure them, I'll have to look and see what i have or bring stuff home from my work toolbox and measure (my Wiha wing torx set and some digital micrometers, etc).

Is that the consensus, to put the bearings up against the pivot and just some "breathing room" to the other side of the balls which typically ends up being 8mm? (0.315" instead of 0.3125" with a pivot of 3/16")

Thank you for the quick reply! This is going to give me great insight and i will post pictures as i do this before during and after.

The knives of interest at the time now are my kershaw blur, kershaw tremor, spyderco resilience, and if (and only IF) there's enough metal there, my Bradley Kimura II.

-Kyle

 

[kyle1058]

Pivot Diameters:

Spyderco Resilience- 0.1957" (Note: holes for reverisible pocket clip will impede bearings/race)

Kershaw Blur - 0.1635" (Note: cutouts for SpeedSafe spring-assist will not allow for a bearing race to be machined or added)


Kershaw Tremor - N/A

Bradley Kimura II - Bite 0.18690" _ Safe 0.18670" (C-sink depth 0.066", handle thickness .128"

Boker Kalashnikov - spring is where bearing race would go; not possible.

Kershaw Select Fire - 0.1955"


Those are the couple knives i had on the desk and considered.. The only promising one is the Kimura II, but it's already pretty damn smooth, and some of the other knives are already spring assist or auto, or just not possible.

The spyderco resilience I will have to do a little work to work around the pocket clip holes, but its do-able.

I suppose I will have to use a smaller endmill (1/4"?) and interpolate the hole just a hair bigger than the pivot plus 2x the diameter of the 1/16" balls. (a couple thousandths?)

How deep is the consensus of the race?

I am really starting to think i don't have a an 'awesome' host for this project, but i want to do it even if i have to buy some knives to do it.

Thank you!

-Kyle