Ball Bearing Folder?

Well, Brad Duncan had done one in sealed bearings, as you asked.
The most popular system is the I.K.B.S. (Ikoma Korth Bearing System), used by Ikoma, Korth, Michael Burch (got to play with the Dao flipper last week, Michael. Smooth!), Les Voorhies, Todd Begg, Charles Marlowe, Mikkel Willumsen, Darrel Ralph, Don Carlos Andrade, Ryan Bailey, Benchmade, and others.
I got to meet Flavio Ikoma last week at a get together we had here in the SF Bay Area... A real nice knifemaker from Brazil.
 
Interesting. I looked at the Ikoma Korth Bearing System page and it looks like they cut grooves on both sides of the blade around the blades slightly over sized pivot hole,. This groove would have to be the diameter of the threaded pivot pin plus the diameter of 2 ball bearings. Assembly must be with a sticky grease and with the pivot pin in place and the grooves filled with bearing the liners are positioned and when the pivot screws are tightened the balls ride between the pivot, the blade and the liner. No races or cages and adjustment by tightening the pivot screws. As they point out the tiny bearings are cheap. The precision would be in cutting the groove and hardening or cutting then hardening scale and carbonization free. The fun would be trying to get it all assembled with out losing the bearings or your mind.

The problem with using a bearing and race assembly is size plus the fact that if the outside race engages the blade the inside race would have to be slightly wider to keep the outside race from dragging on the liner. Now your side play would be dependent on the fit of the balls between the races and I don't believe that is a great function for ball bearings, especially in the widths of knife blades

I think I will stick with good clean polished holes and pivots.
 
Ib2b4b: the races are cut into the liners..,not the blade.this system is very easy and effective when done correctly.

The races are simply cut into the handles with a piloted counterbore.as long as races are cut .10 deeper then needed,you could use .10 piece or hardened steel (washer) or something similar to avoid bearing digging into races.with bearings seated between hardened washer and blade,chances of any wear are very slim.i find assembly of bearing systems easier then say standard bushing set-up's.simply apply very thin layer of grease and the bearing stay right where you want them.
 
I've looked at the I.K.B.S. webpages and have a question:

I see how the ball bearings are providing alignment and support of the blade between the liners, reducing friction and play between liners. Are they also supporting the blade on the pivot pin, or does the blade pivot hole still bear on the pivot pin? I mean to say does the blade still ride on the pivot pin or do the bearings hold a clearance between blade and pin? (Hope that came out right.)

-Ben
 
The ones I have made, the blade still rides on the pivot, though I relaxed the hole diameter a little more than I would without IKBS.

Also, for channel designs, it becomes necessary to mill the races into the blade instead of the handles...

I use a nice, sharp, 5/16 end mill to counterbore the race.
 
So does anyone have a tutorial or be willing to write one. Where do you get the bearings and what size is best. Knife works, what do you mean by channel designs and I take it you drill your pivot hole then go to the end mill and cut the race? How deep is this cut? 1/2 the diameter of the ball? less more? I can see that with small balls and some stiff grease that it wouldn't be that bad to assemble and should work well.
 
If you intend to use (ikbs) on a private knife..,that is fine!if you plan to make and sell knives with this feature you will need approval.no cost,they just want to make sure the system is working correctly before you sell knives with it.

In most cases,guys use a piloted counterbore.5/16" counterbore with 3/16" pilot.i'd love to find one with smaller pilot.the race depth needs to be drilled according to your spacer depth.most knives will be different.

DDR has a simalar patented system..,i dont yet know all the specifics on it,but i dont think anyone can just use this system.
 
balibalistic said:
If you intend to use (ikbs) on a private knife..,that is fine!if you plan to make and sell knives with this feature you will need approval.no cost,they just want to make sure the system is working correctly before you sell knives with it.
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That's very generous. I'm discovering that there sure are a lot of good (as in moral, honest, charitable) people in this trade.

-Ben
 
The deal with selling IKBS is marking them all as IKBS.
Pretty sure they want to see one as well to grant the license.
Duane @ edcknives facilitated licensing for me. I did one channel constructed bali before committing to a collab with Warren Thomas, and let EDC play with it for a while. Duane was the liason for Ikoma and Korth, and granted me license to use it.

ib2v4u, channel construction is when the handle is made from one piece of material, rather than a sandwich of pieces, like normal.
Think Lochsa....
Left side, right side, and backspacer all all one piece....

And yes, finish the pivot hole (for me, drill, ream, and lap) then spotface the race. (in the handles for sandwich, the blade for channel)
1/16" SS balls.
Race depth cut greater than 50% ball diameter. Actual depth depends on a few factors like how much space you want between handle and blade, how thick of spacer material you have, etc...
McMaster sells the balls, but there are better places if you intend to make very many knives...
I don't have a link right now as I am in Africa, but can when I return to the states...
 
I got it on the channel. I did the only butterfly I have made that way. Thanks for all the information. I may try this out on a knife. It really doesn't sound that hard. Time time time.
 
I have made a Bali using the IKBS. A channel bali like knifewerks mentioned, with the race milled into the blade. You can see the race in one of the attached pics. The pivot holes in the pic are shown with dowel pins inserted into a fixture for location purposes. If I were going to do a channel bali using IKBS again I think I would do it a bit differently though. Rather than milling the race into the blade I think I would make some inserts that had the race machined into it that could be dropped in from the topside of the channel. By milling the race into both sides of the blade you end up with a quite thin web between the two sides. By using an insert you will maintain some bearing surface between the pivot pin and the pivot pin hole in the blade thereby strengthening the attachment point and making the blade a little less prone to side play. I found the IKBS to be an excellent system and Duane at edcknives a very helpful and knowledgeable maker. I never did get licensed to use the IKBS but that was my fault. After making the one bali and realizing the different method I described about the inserts I wanted to send a working model that I have yet to make due to other projects. When, not if I make another, IKBS will be the system I choose. First because it is a rock solid, proven butter smooth method of a pivot system and second because I will have the opportunity to get more help from the guys that support and came up with the system. Those would be the "generous,moral, honest, and charitable and more importantly very helpful makers messinger mentioned :thumbup::thumbup::thumbup: As you can see, Brian Felhoelter of KnifeWerks will gladly give you all the help you need regarding IKBS too. He is a great guy to ask for help :thumbup:

In response to using sealed ball bearing in the pivot I have been told that these type of bearings are not exceptionally strong when it comes to lateral stress'(side to side play). Contained within a set of scales this may not be an issue but I can't speak from experience regarding this, its something to think about though. Maybe someone with a bit more experience with sealed bearings could address this issue.
 

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howiesatwork said:
The most popular system is the I.K.B.S. (Ikoma Korth Bearing System), used by Ikoma, Korth, Michael Burch (got to play with the Dao flipper last week, Michael. Smooth!), Les Voorhies, Todd Begg, Charles Marlowe, Mikkel Willumsen, Darrel Ralph, Don Carlos Andrade, Ryan Bailey, Benchmade, and others.
Click to expand...
Just to keep the record straight, Darrel Ralph (Ryan Bailey) is no longer licenced to use the IKBS, Don Carlos does not make folders, and Benchmade has not made a bearing system of any kind to date. (Ikoma and Korth put IKBS into a BM32 just to show it could be done.)

As long as we're talking about bearings, Larry Chew has been putting bearings in his folders longer than anyone, and I'm pretty sure that Mel Pardue tried it before all of the above.
 
I mentioned those that had, at one time or another, put IKBS in a folder, Duane.
I gotta go look at where I found the Don Carlos folder...
Thanks for the update.
 
Dan could you show an example of just how you mount the bearing. I am curious as to how you keep the outer race from rubbing on the liners. do you use a thin washer on both sides of the inner race or what. I would think side force not a huge issue as the sides of the blades pivot area would contact the liner before the bearing is damaged with a good fit.
 
ib2v4u said:
Dan could you show an example of just how you mount the bearing. I am curious as to how you keep the outer race from rubbing on the liners. do you use a thin washer on both sides of the inner race or what. I would think side force not a huge issue as the sides of the blades pivot area would contact the liner before the bearing is damaged with a good fit.
Click to expand...


sorry I've been out most the day,,
I don't have a picture but I will say I lightly press fit them the bearing is thinner than the blade so I just center them..and I do use washers on both sides not because of the bearing but for the side thrust of the blade.

this is one I've used you can get it at your local bearing dealer I'm sure
SSRI 418ZZ YO4 1/8" x 1/4" x .193
 
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