Detent ball hole placement

[Txcwboy]

I am just about ready to put the finishing touches on my first completed folder.I still need to send it off to be HT and finish up the sanding to make it purdier. I have had to redo the handle once and stop pin a few times till I got it tight. I finally got it to lock tight although my lock does go a tad too deep into the blade but its my first so whatdaheck.That means the stop pin is too low I believe. I checked Rays site and I dont have a "pile" to reference putting the hole and my Bob Terzuola book says .020 from top of the swing line. So is this about where it should go ? check the pics please

thanks and comments welcome.

Dave

my line is so fat that its hard to tell but its at the top of the line

http://www.baldcowboy.com/images/detentball.jpg

[JeffreyPrater]

I have tried to drill for the detent like Terzuola shows in his book and could never make it work. After I got Don's book I drill thru the liner into the blade the way he shows with a #53. Change bits and drill the hole a little bigger in the liner; and it works for me. It is the only way I have ever been able to make a consitent detent lock up.

I know others who have good success drilling .020 past the line, I have just stayed with what works for me.


Jeff Prater

[Txcwboy]

Ahhh.... I need to get his book, I was working from Rays site ( I typo'd . I want to try out everyway to make them till I find my way.

thanks

Dave

[Don Robinson]

Dave, I got your private message about the book, but I'm not sure whether my reply made it through.

Anyway, click on the link below for my Knifemaker's Supply web site for the book.

[Txcwboy]

Got it Don

thanks

[Ed Caffrey]

I'm one for drilling through the liner and into the blade also. I manually hold the blade in the closed position (without scales on the knife) and drill first with a #55 Hi-Roc bit (my blades are already heat treated when I place the detent ball) and then drill through ONLY the liner with a #53 bit. (this is for a 1/16" detent ball) I use a smaller hole in the blade than the detent ball size...otherwise your folder will have "slop" in the closed position from the detent wallowing around in a hole that's too large for the 1/3 diameter that is protruding.

[JeffreyPrater]

Sorry I said it backwards, Ed is right. I edited the other post, didn't want to confuse anyone.

I drill thru the liner and into the blade with a #55 then drill the liner only with a 53. I drill my detent holes before heat treating. I haven't had any problems but drilling them after you heat treat would leave less chance of some slight warpage causing a problem.

Ed, I assume Hi-roc bits are carbide, where do you buy them?

Thanks,
Jeff Prater

[Ray Rogers]

Hi-Roc are carbide, also called Straight Flute Carbide drills. MSC, McMaster-Carr, Enco...just about every large supplier carries them.

I use a 1/16th carbide spade drill to make the detent hole in my already hardened blades. My method avoids the slop that Ed mentions because the hole is placed about 20 thou off center by drilling on that 'pile' Jeff mentioned....

[Txcwboy]

so is my X at the right spot ? I already have the detent ball installed. So do I knock it out and do it thru the liner method ?


Dave

[Ray Rogers]

Well, it LOOKS like it's in the right spot but that's hard to say from the picture. Think about it like this: the end of the curving track made by the detent ball was made by the center of the ball. If you drill precisely on that center mark the ball will sit down in that hole and make contact all around its surface at whatever depth you drill IF the drill point has the same shape as the ball (not likely). Because that isn't likely, you would have to do as Ed suggested and drill the hole at a diameter smaller than the ball to force that nice, even contact that will result in a solid feeling detent. That's one way, and it's a good way.

Another way is to move about .020 (about 1/3rd the diameter of the ball) beyond the end of that track and drill the hole. My way of accomplishing this measurement is to put some Dye Chem on the track, assemble the knife, move the blade, and look at the track under high magnification. At the end of the track you will see a small pile of Dye Chem. This pile is beyond the center of the ball so if you drill directly on top of that pile you will be drilling beyond the center of the ball. When the ball goes into the hole it will not be able to go all the way down because it is off center from the hole. It will ride down the side of the hole pulling the blade after it. This method doesn't care what shape the hole is or what diameter as long as the diameter doesn't exceed ball diameter by more than .020 and it will also result in that nice solid detent feel.

Using either of these methods can be done with the ball in place (and should be). Drilling through the ball's socket is an entirely different approach which also works well and it's a matter of choice and experience which method you may settle on in the future. Right now, since the ball is already in place, I'd give more consideration to the methods that let the ball stay seated...

[Txcwboy]

I painted the area with a sharpie several times and put it back together and worked it a few times. It left a little pile somewhat So i drilled there and it seems to click when closed....so I think i got it . I need to send it off to be HT now .

thanks for all the help

Dave