Slipjoint pivot not disappearing

[ashwinearl]

Attached is the tapering tool A. Vigil pointed me to. I use 3/32 holes though. I can't tell from your picture what size that pin is, it looks bigger. I initially went to town with it. Now much more sparingly, just enough to feel small burr work up around the edge.

 

[Hengelo_77]

Attached is the tapering tool A. Vigil pointed me to. I use 3/32 holes though. I can't tell from your picture what size that pin is, it looks bigger. I initially went to town with it. Now much more sparingly, just enough to feel small burr work up around the edge. View attachment 2441386

Those look like the ones that Luke Swenson and Norseman use as well.
Does it remove steel or does it push steel up?

 

[ashwinearl]

Those look like the ones that Luke Swenson and Norseman use as well.
Does it remove steel or does it push steel up?

That is a good question. I am assuming it removes steel to create area for pin to swell into. In a good ol blades podcast (https://www.thegoodolbladespodcast.com/2093014/12398744) Matt Collum talks about how a common mistake is to use the reamer too much. He discusses to just use it enough to raise small burr

 

[aandreotti]

Important. Use the same kind of metal in pivot and pin.

 

[Jason Fry]

I've had some luck upsetting my pins in my mill vise. Since the vise jaws are smooth and square, you can just set up the pins with flat heads and give it a squeeze.

I'm in the group that gives the hole the slightest bit of countersink. Like two turns by hand.

Another trick, sometimes you can hide that ring without messing with the overall tension of the pin by peening the ring/joint itself. I use a 3/32 punch with a domed head, and a 2 oz hammer, and lots of tiny taps. You are basically using the tiny punch like a tiny hammer and peening the joint closed.

 

[Stacy E. Apelt - Bladesmith]

I have used a hammer handpiece on a Flexshaft with a 1/16" carbide hammer tip the same way.

 

[A.McPherson]

I have used a hammer handpiece on a Flexshaft with a 1/16" carbide hammer tip the same way.

A jeweler buddy of mine over in Korea uses a small piece of "L" shaped Allen key like a hammer handpiece, but in the normal "Chuck" style handpiece.

It's mirror polished on one end, and he just revs it up and then gently brings it into contact with the surface he wants to hammer. It's pretty genius!

 

[SBuzek]

Another thing that no one has mentioned, it is possible to remove too much material from the bolster or washer and remove the actual hidden part of the pin.
Have your bolsters or pivot washer 95% complete before peening. It should take a very light cleanup after.
I take everything to a super clean 400 grit before peening the knife together.

 

[Hengelo_77]

I managed to do it but I took the knife apart again. I think I figured out what the problem is.
I was working on a linerless slipjoint with thin CF scales. Because they are not as stiff as metal liners the knife bounds up before the pin has swolen enough to disappear in the hole. I'll first work on two slipjoints with stainless liners before coming back to this one.

I did some tests on how strong a stainless pivot actuallly is.
I use 3mm pin stock and I reamed the hole one 360degree turn with a 1:50 reamer.
I ground it down like normal, put a vice clamp on the other side of the pin and stood on it with my 185lbs body weight.
It held and still didn't show on the other side!
No way on earth a slipjoint will ever experience such forces in the real world!
So that gives me confidence that I'm using the right tools and technique. Unbeleivable how strong a very small bit of stainless is!

 

[Way-Barney]

I managed to do it but I took the knife apart again. I think I figured out what the problem is.
I was working on a linerless slipjoint with thin CF scales. Because they are not as stiff as metal liners the knife bounds up before the pin has swolen enough to disappear in the hole. I'll first work on two slipjoints with stainless liners before coming back to this one.

I did some tests on how strong a stainless pivot actuallly is.
I use 3mm pin stock and I reamed the hole one 360degree turn with a 1:50 reamer.
I ground it down like normal, put a vice clamp on the other side of the pin and stood on it with my 185lbs body weight.
It held and still didn't show on the other side!
No way on earth a slipjoint will ever experience such forces in the real world!
So that gives me confidence that I'm using the right tools and technique. Unbeleivable how strong a very small bit of stainless is!

That's a beautiful knife, and fantastic testing.

Rivets are amazing and incredible fasteners, several times a year I drive over the Menai bridge, designed by Thomas Telford and opened in 1824 as the first and largest suspension bridge in the world, held together by hundreds of thousands of hot rivets for 200 years. Almost every aircraft and jet flying about is held together by rivets in some form or other.

 

[Hengelo_77]

I did it, thnx for all the help!
It's a 3mm V2A =304 stainless pin that disappeared in a 8mm shadow disk.
I used a 50:1 reamer and gave it one full 360turn. I left 1mm sticking out on either side and gave it a few firm but not hard taps with a flat faced hammer.
I did the pivot pin first before I put tention on the spring, that way you can feel if you're getting to tight.
The middle and back pin are confex hammered with a cup punch.
My new EDC

 

[Way-Barney]

I did it, thnx for all the help!
It's a 3mm V2A =304 stainless pin that disappeared in a 8mm shadow disk.
I used a 50:1 reamer and gave it one full 360turn. I left 1mm sticking out on either side and gave it a few firm but not hard taps with a flat faced hammer.
I did the pivot pin first before I put tention on the spring, that way you can feel if you're getting to tight.
The middle and back pin are confex hammered with a cup punch.
My new EDC

Those pins look amazing!
Did you jig the scale before or after?

 

[Hengelo_77]

Those pins look amazing!
Did you jig the scale before or after?

Thnx. I first shaped and contoured the bone scales. After that I jigged them and coloured them with possasium permanganate. Then I put the knife together and sanded trough the dark sides to get to the white bone on the sides.

 

[Sean Yaw]

I did it, thnx for all the help!
It's a 3mm V2A =304 stainless pin that disappeared in a 8mm shadow disk.
I used a 50:1 reamer and gave it one full 360turn. I left 1mm sticking out on either side and gave it a few firm but not hard taps with a flat faced hammer.
I did the pivot pin first before I put tention on the spring, that way you can feel if you're getting to tight.
The middle and back pin are confex hammered with a cup punch.
My new EDC

Did you make the cup punches?

 

[Hengelo_77]

Did you make the cup punches?

Yes I did, I made a shallow hole in the middle of 6mm roundstock with a 3mm ball nose end mill and tapered the roundstock. The pins are 2mm.

 

[Hengelo_77]

A follow up I wanted to share.
I finally found the problem. Not all pin stock is created equily!

I have a 3mm pivot hole and I use 3mm pin stock.
Pin stock is slightly undersize and I didn't know that there are degrees of presicion/tolerances on this subject.

I measured the stock that kept giving me problems and it is 2.96mm
I ordered a higher tolerance and it is 2.98mm
0.02mm ~ 8/1000" and that was my problem, my pin stock was to thin!

I put some fast and simple paper micarta handles on two knives that where written off to practice peening and I did it again!
You guys don't know how relieved I am!