Pressing in a ball bearing?

blindhogg

blindhogg

Joined
Feb 21, 2001
Messages
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Alright guys, I am in the middle of a folder (Flipper to be exact).
And I would like to know how you guys press in a 1/16 hardened ball bearing into a Frame.
FYI I am making a framelock folder with .100 Ti frame.
So my question is

1. What size hole to be drilled?
2. when I press it in do I have a shim to ensure I dont press it in to far with my arbor press.
3. Do I need to do anything to keep it from coming back out, Hammer around hole? Loctite?
4. Am I missing anything?

Thanks
Chris
PSS I am taking pics so plan to make a WIP to share later.
 
A lot of people simply tap them in with a small hammer.
 
I can't answer all your questions, but you want to use a #53 drill bit, and from what I've been told you need to use a washer of some type around the ball to keep it from being pressed in too far. How thick of a washer depends on how much of the ball you need protruding above the scale to engage the detent hole in the blade.
 
Wish I knew what you are talking about, JM. From here it doesn't sound logical.

Why not just drill the hole to the exact depth? It can't come out very easily, as it's always held in place by the blade, isn't it?

I'm probably speaking out of turn here, since I haven't studied or done it. Just kind of a fun little brain stimulator.
 
Grizz,
You make a point. I have only made fixed blades up until now. I'm just now working on my first folder proto and am only passing on what I've been told by others at this point. Drilling the hole to depth seems to make sense, but I own countless factory and production knives that have a detent ball set into a hole drilled all the way through the liner or slab, so there must be something to it. Maybe one of the more experienced folder makers will chime in here.

One thing I should note is that there is not always pressure on the detent ball. When most folders with a detent are in the open position, the ball is sitting exposed without any pressure, requiring a solid fit to keep it in place.

grizzled gizzard said:
Wish I knew what you are talking about, JM. From here it doesn't sound logical.

Why not just drill the hole to the exact depth? It can't come out very easily, as it's always held in place by the blade, isn't it?

I'm probably speaking out of turn here, since I haven't studied or done it. Just kind of a fun little brain stimulator.
Click to expand...
 
jonnymac44 said:
Grizz,
You make a point. I have only made fixed blades up until now. I'm just now working on my first folder proto and am only passing on what I've been told by others at this point.

Drilling the hole to depth seems to make sense,
but I own countless factory and production knives that have a detent ball set into a hole drilled all the way through the liner or slab, so there must be something to it.


Maybe one of the more experienced folder makers will chime in here.

One thing I should note is that there is not always pressure on the detent ball. When most folders with a detent are in the open position, the ball is sitting exposed without any pressure, requiring a solid fit to keep it in place.
Click to expand...


A through hole will allow you to punch out the ball and replace it.
Maybe it takes a couple of tries to set the ball


A blind hole with a hardened ball in it - you might get that out with EDM, but nothing conventional.

Bob's book has all those details.
http://www.amazon.ca/Tactical-Folding-Knife-Bob-Terzuola/dp/0873418581
 
Count,
Thanks for the input and for the link. It reminded me that I would really like to have Bob's book on hand as I progress into folders. Is it really that expensive?? Google shopping results didn't turn up anything less than $117 for a used copy from what I could see.
 
jonnymac44 said:
Count,
Thanks for the input and for the link. It reminded me that I would really like to have Bob's book on hand as I progress into folders. Is it really that expensive?? Google shopping results didn't turn up anything less than $117 for a used copy from what I could see.
Click to expand...

Yes it is! I've watched for months for a cheaper copy... Don't you love how it has the $16.95 price on the back cover? ;) **I forgot to mention, this book is available at many local libraries, in case you want to look at one for reference...

By the way, this is what Bob says in that book about the detent (Chapter 6, page 98):



10. Locate the position of the ball bearing detent
(Fig. 141). I use a 1/16-inch ball and it can sit
anywhere in the triangular area previously scribed
on the spring. Drill the hole with a #53 drill and
set the ball bearing into it leaving about .020
inches standing out (Fig. 142). The undersized hole
will close around the ball, locking it in place. The
exposure of the ball is determined by the thickness
of the washers which will be used as side
bearings between blade and handle after the knife
is assembled. I use .020-inch washers so the ball
can be that high above the spring, but not more, or
else it will interfere with the smooth operation of
the blade (Fig. 143).
Click to expand...


Hope that helps (and that I'm not in violation quoting out of the book here)! Good luck, Brother!
 
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It's also actually more difficult than one would think to drill a blind hole, and have the ball end up at the right height, unless you were to drill a flat bottomed hole...

And then, if it's too deep, or too shallow, you can't knock it out, and try again...
 
Wow thanks everybody, now I am ready to put one in this weekend.
Johnnymac, thats exactly what I was thinking when I mentioned using a shim to keep from over-inserting in my initial post (GMTA).
I think I have decided to go the through hole route.
Amcardon, Thanks for the link and post from Bobs book. That was very helpful.
Now off to ream a bunch of holes.
Chris
 
Chris
You don't need to use the arbor press to put the ball in.I use my 1" micrometer and press the ball in with it and a washer and still know I'm getting to the right depth.
Stan
 
Sbuzek
Great tip, I can see how that would be plenty of leverage. Plus you know at what depth you are pressing it in as an added bonus.
I will post of my results using this technique, Thanks.
Chris
 
Chris, please don't use your micrometer for anything except measuring.

They aren't clamps, or vises, or presses.

Well, they can be I suppose, but then they are no longer a precision measuring instrument.
 
Fellhoelter
Point taken, I will go to work and get my chinese 1" micrometer to use. I dont expect much from them and I really have to try this technique. If it works like I think it might I will dedicate it to this job only.
Ill save my Brown & Sharp for delicate work.
Chris
 
I just always look at things like this with my Shop Foreman eyes.

I'd send a man home the first time I saw him do this, fire him the second time.

Had to send a guy home once for twirling his mic to open it up fast.
He had been warned once before...
It was his tool too, but as the boss, I have to be able to rely on my men, and their equipment.

Precision tools are only precise if you treat them right.
And a good one will last a lifetime.

I have tools that were my grandfathers from the 40's to the 70's and I have been using since '90 and they will still pass inspection.

We're talking 50 years of professional use...

They don't get twirled, they aren't presses, nor are they clamps.

Tool abuse is a peeve of mine.
 
The way I do it.

For a 1/16 (1.58mm) bearing

Chuck a 1.5mm drill and use the depth stop on my milling machine to lower the drill until the tip just touches the handle.

Stick a 1mm thick piece of metal underneath the handle and drill the hole. It will be exactly 1mm deep.

Hammer the ball in with a hammer and a piece of soft steel as a punch.

The top of the ball should be around 0.7mm above the surface.

If the ball becomes worn, dissolve it out with ferric chloride and replace. This only works with stainless steel balls, NOT ceramic.
 
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