*update* Has anyone added bearings to their knives?

I was actually thinking about trying to do that to some of my spyderco knives after buying my zt0561 and taking it apart. Let me know how the process goes. I would like to try it and have it done on some on mine.
 
Hairlesstwinkie said:
So which one would fit on the Southard flipper? I'm looking to see if there's a way to upgrade my Southard.
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You will have to take apart your Southard and take some measurements, but I don't think it will help much. I can't imagine these bearings being much of a step up from the ones already in the Southard.
 
bpeezer said:
You will have to take apart your Southard and take some measurements, but I don't think it will help much. I can't imagine these bearings being much of a step up from the ones already in the Southard.
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I don't have anything to measure it... I have taken mine apart, and I thought maybe having all of it being SS instead of SS and plastic.
 
Hairlesstwinkie said:
I don't have anything to measure it... I have taken mine apart, and I thought maybe having all of it being SS instead of SS and plastic.
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I didn't realize they use plastic housings for their bearings, thanks for the info! To measure it, take a picture of the bearing next to a dime, with the bearing and dime touching a straight object. Send the picture to your computer, and open it with paint. Paint shows pixel count in the bottom left hand corner of the screen.

A dime should have a diameter of .705", so check the X axis pixel count on either side of the dime. If its 200 pixels, then you know 200 pixels = .705". Then check the X axis pixel count for the bearings. Suppose its 100 pixels. Since your scale is 200 pixels = .705", then with some simple math you know that 100 pixels = .3525".

Does that help with your measuring problem?
 
When I replaced the (much larger) ball in my manix 2 xl, I used a ceramic ball bearing. These are a step up from steel in terms of roundness, harness, smoothness, and trueness to spec size. You may be able to find similar bearings in smaller sizes to upgrade knives with similar bearings (loose bearings in a race)
 
PigmonkeY said:
When I replaced the (much larger) ball in my manix 2 xl, I used a ceramic ball bearing. These are a step up from steel in terms of roundness, harness, smoothness, and trueness to spec size. You may be able to find similar bearings in smaller sizes to upgrade knives with similar bearings (loose bearings in a race)
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Thanks! I'd like to give that a shot at some point too. Right now I'm looking at bearings in washers instead of loose bearings, just because I'm concerned about simplicity for my first attempt. Do you know if the ceramic bearings work better with different lubrication than steel ones?
 
The ceramic bearings are EXTREMELY smooth, they almost don't need any lubrication at all. I find they work best with a light machine/sewing machine oil, or tufglide. But overall they're so smooth they really don't need it. Because of the high hardness, you're unlikely to get any rough spots.

And the "washer" the bearings are contained within is referred to as a bearing race =]
 
PigmonkeY said:
The ceramic bearings are EXTREMELY smooth, they almost don't need any lubrication at all. I find they work best with a light machine/sewing machine oil, or tufglide. But overall they're so smooth they really don't need it. Because of the high hardness, you're unlikely to get any rough spots.

And the "washer" the bearings are contained within is referred to as a bearing race =]
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I didn't call it a race because I thought the race was just the track the bearings rolled on, thanks for the clarification :)

Also, due to some other tooling I think I may need, my timeline for this project has been pushed back a little :( I will probably get to it late May/early June
 
In a pocket knife, ceramic bearings shouldn't need lube at all, the coefficient of friction is already very low. It will only attract dirt and stiffen things up. Just blow out the pivot with compressed air now and then to keep the pocket lint and dirt at bay. As far as the bore tooling, you should use 2 endmills for a good precise fit. One to rough plunge to say .015"-.030" undersize and slightly shallow and one right at finish size and depth. Ideally you would use a smaller endmill in a CNC and circular interpolate, but it sounds like you don't have that capability. A good source for small steel ball bearings is radio control ball-bearing servos. I'd imagine they can be had cheap as dirt used.
 
eKretz said:
In a pocket knife, ceramic bearings shouldn't need lube at all, the coefficient of friction is already very low. It will only attract dirt and stiffen things up. Just blow out the pivot with compressed air now and then to keep the pocket lint and dirt at bay. As far as the bore tooling, you should use 2 endmills for a good precise fit. One to rough plunge to say .015"-.030" undersize and slightly shallow and one right at finish size and depth. Ideally you would use a smaller endmill in a CNC and circular interpolate, but it sounds like you don't have that capability. A good source for small steel ball bearings is radio control ball-bearing servos. I'd imagine they can be had cheap as dirt used.
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Instead of using a CNC to do the circular interpolate, would it work the same with a rotary table on a manual mill? Might save me a few thousand bucks :)
 
Sure it would, I just didn't suggest it because it would be a lot more time consuming. It sounded like you were thinking of offering this as a service, in which case you'd try to keep it as cheap as possible. However, you could always just make a few fixtures and jigs to make it go pretty quick even with manual machines.
 
In the long run, I might like to do more volume, but I have to get it to work once before I can expand :rolleyes: I will be purchasing CNC machinery at some point in the future, but not specifically for this project. Thanks for the help :)
 
No problem. Don't forget to c'bore or use a spacer so the proper race hits on the proper face if you go with ball bearings instead of thrust bearings! I was thinking thrust bearings might be a little too thick to fit into your space envelope, but maybe you'll find some super-thin ones.
 
The smallest thrust bearings I can find are 33% thicker than the caged ball bearings I was looking at. I could potentially use the thrust bearings if I had more space between the liners and blade, but I'd have to get bigger standoffs then too. As I delve deeper into this project plan I find more and more complications!
 
Yeah, it's tough to find little thrust bearings. I had a feeling it would be difficult to source something small enough. Keep looking though if you're set on thrust bearings, you might get lucky. I'll see what I can find with a bit of looking too. The majority of itsy bitsy bearings are used in micro stuff and might not hold up well in a heavy-use knife pivot. (Think watch rotor ball bearings, for example). If worse comes to worst, you could always buy the skinniest ones you can find and surface grind the outsides of the races.
 
I received my bearings today, and ran into a little trouble on my first attempt :o the tool I used to mill the race turned out to be insufficient, it only cut to a depth of ~.012" before becoming heavily damaged. Besides this hiccup, the concept seems like it will work. I will look into better bits, and hopefully have better luck in the next iteration of the test!
 
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