Bearings and Settling/Wear in Titanium Raceway

[Erin Burke]

Hey guys,

One of my next projects is going to be my first attempt at a frame-lock folder. I decided to go with these bearings from Chuck at Alpha Knife Supply.

(Photo from AlphaKnifeSupply.com)

If i mill my raceways into the 6al-4v frames, how much wear-in can I expect as the bearings "break-in" and develop a groove in the Ti? I'm wondering if I should counterbore my 1/2" raceways ~0.01" short of my calculated depth to accommodate settling of the bearings and tightening of the 3/16" pivot. Any thoughts?

Thanks.
Erin

 

[Salem Straub]

I think the difference is much less. Maybe not enough to change the desired depth of your counterbore. Check this out:

http://www.ikbsknifetech.com/20801.html

I've not tried it yet, looking forward to it- I have no doubt that your efforts will be quite successful.

 

[seamus]

I think you're only talking about a .001" difference per side after the bearings form a slight track within the races.

 

[Carl_First_Timer]

I think you're only talking about a .001" difference per side after the bearings form a slight track within the races.

That is what it says on the IKBS site, but I THINK they are a a few though off. I emailed them asking to clarify, and never got a response.

I base that off of this picture.

 

[Fellhoelter]

The difference I experience is more in line with .0015 - .0025 per side.

But, I only measure with gauge pins and such, not precision calipers!

The best way I have come up with to break them in is with a spinning rod in my mill.

I have a rod with a hole in the middle that goes in the spindle, and a fixture plate with a pivot sticking up.
Line these up on the machine.
Handle and bearing go on the fixture plate, and the mill is fired up at a few hundred RPM.
Bring the rod down, with moderate pressure, and let is spin, forging a track into the handle.

I don't like the vise technique at all.
I end up with dimples in the race.
Dimples from when I am applying the pressure and the bearings are not rotating, and possibly from where I stop to change directions...

 

[Erin Burke]

The best way I have come up with to break them in is with a spinning rod in my mill.

I have a rod with a hole in the middle that goes in the spindle, and a fixture plate with a pivot sticking up.
Line these up on the machine.
Handle and bearing go on the fixture plate, and the mill is fired up at a few hundred RPM.
Bring the rod down, with moderate pressure, and let is spin, forging a track into the handle.

Thanks Brian, that actually makes sense and sounds fairly simple to make. I don't suppose that you have any photos of you setup.

 

[Bob Katilus]

Yes, a photo of your set up would help me understand. Sounds like a good idea.

 

[jakehobackknives]

I'm with Brian, Got about 75 folders out right now with the bearings they settle about .002-.003. I usually open the blade about half way, remove the back spacer, then slowly close they blade while tightening the pivot hard, then put some rubbing compound int there and start opening and closing a bunch, then loosen the pivot and... Butter

 

[Monkeyz]

Hey guys,

One of my next projects is going to be my first attempt at a frame-lock folder. I decided to go with these bearings from Chuck at Alpha Knife Supply.

(Photo from AlphaKnifeSupply.com)

If i mill my raceways into the 6al-4v frames, how much wear-in can I expect as the bearings "break-in" and develop a groove in the Ti? I'm wondering if I should counterbore my 1/2" raceways ~0.01" short of my calculated depth to accommodate settling of the bearings and tightening of the 3/16" pivot. Any thoughts?

Thanks.
Erin

I can't find these anywhere, does someone know where I might be able to find some?