First slip joint WIP

J S Machine

Well-Known Member
You took the words out of my mouth Ernie :) Check this out - -

Now is when you start to get excited folks :) I can't help but hide my emotion. Everything is falling into place, and I still can't believe I have almost pulled this off. I etched the blade last night and today I got some sanding done. All there is left to do is pin this thing together and polish it up.

This was the second time using the etcher and I didn't do as well as I would have liked. I thought I hadn't etched enough, but in turn after I removed my stencil I saw that I had kind of over done it. It's ok though. You live and learn right?

Here we are etching the blade-
Today when I got home I started the final sanding on the dummy pined handle/spring assembly. I started with a rough grit belt - like 120 or so and worked up to about a 320. I learned a very good lesson here, and it is that you can take too much material off. I hate that had to remove so much of the stag because it really s good looking. I used to hate the look of stuff like this, but it is really growing on me :) The better thing to have done would have been to thin the scales a little more than I did, then so much wouldn't have come off the surface trying to work them into a blend with everything else.

Here we are ready to etch. You can see the final grinds are done on the blade as well, except for sharpening-

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And the etching process -
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And finished; You can see that I went a little deep. The etch is supposed to look like my avatar-
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And then today I was doing the final sanding rough in. Here are some pictures of the process and during on the 120 grit belt-
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And here I have moved up to a 320 grit belt on the little 1x30 grinder-
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And then finally, after a quick clean up and blowing off, the handle assembly as close as it is going to get before we pin it together -
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All there is left to do is turn some .188 (3/16") 410SS rod down to .094 (3/32) for use in the three main pins. I don't have any 3/32 so I'm gonna have to make some.

Stay tuned for the final episode :)
 

Ernie Swanson

SASSY PINK LUUNCHBOX KNIFE MAKER
Awseome!!!

Did you try lightly sanding or polishing over your mark?

Sometimes mine look like that. I go over them just a bit with whatever my finished grit is and it cleans them up really nice.
 

J S Machine

Well-Known Member
Ok, time to talk pin peening. I got the thing pinned up last night. I have pictures, but I won't be able to post that process untill tonight. I can tell you about it though. As I mentioned I would have to do, I turned three pins. I assembled the knife last night before I went to bed, but did not peen the pins. This morning when I got to work, I used one of my good hammers here to do it. The rear pin and the center spring pin went well. Everything pulled together as it should have. The pivot on the other hand....:(

I'm not sure what happened here, but I'm trying to figure out what is going on inside that pivot. I got to thinking and I thought of this. Is it possible for the entire pin to swell while it is being peened? I used a clearance shim and all, and I still have a rather tight fit. I used a .003" shim, and I would guestimate that I still have about .010 clearance in there. I didn't even go all the way down. I was checking the blade movement every whack or so and it started to tighten up.

Needless to say, I'm disappointed, but that doesn't mean I failed. I did pull this off, I'm just trying to figure out a way to loosen up this blade. If the pin has swelled then I know I won't get it to loosen up. I just can't figure out anything else it could be. I lubed it up real good, but I still have a tightness that I am not happy with. I would rather it close all the way up to.003 clearance as well to close the gaps on top ion either side of the spring.

Then I thought that if I would have used a bushing it would have worked, but then I thought again. If the pin swells, it will only enlarge the bushing which will then freeze in the blade pivot hole. What am I missing here??
 

JC in SC

Well-Known Member
I'm no expert, so take this as such. I think the intent with the bushing is that the pin will swell to some degree during peening. This will prevent the bushing from spinning on the pin; however, I do not believe the pin will swell sufficiently to cause the bushing to swell such that it binds the blade. Again, I'm no expert, but that is my understanding based on reading Eugene Shadley's book and every slip joint WIP/tutorial I can find. I'll double check Shadley's book when I get home tonight as I cannot recall offhand whether or not he used bushings.

I seem to recall reading a remedy for the issue you're having and I think I remember what the solution was as well. Let me confirm this before you use it, but I think I read that some makers, when experiencing the tightness you have here, will very lightly twist the blade orthogonal to the pivot to loosen it ever-so-slightly. Again, I'd like to confirm my information first though so you don't do anything disastrous based on misinformation from me. Intuitively, it seems like a bad idea to me, so again, let me try to substantiate this before you try it. If anyone can confirm/disprove what I've written here, please do so, you certainly won't hurt my feelings.

I have seen some makers spinning heads onto their pins, but cannot recall whether or not that was limited to the handle pins. We do similar processes here at work and it seems much more controllable/repeatable than peening.
 

J S Machine

Well-Known Member
I'm no expert, so take this as such. I think the intent with the bushing is that the pin will swell to some degree during peening. This will prevent the bushing from spinning on the pin; however, I do not believe the pin will swell sufficiently to cause the bushing to swell such that it binds the blade. Again, I'm no expert, but that is my understanding based on reading Eugene Shadley's book and every slip joint WIP/tutorial I can find. I'll double check Shadley's book when I get home tonight as I cannot recall offhand whether or not he used bushings.

I seem to recall reading a remedy for the issue you're having and I think I remember what the solution was as well. Let me confirm this before you use it, but I think I read that some makers, when experiencing the tightness you have here, will very lightly twist the blade orthogonal to the pivot to loosen it ever-so-slightly. Again, I'd like to confirm my information first though so you don't do anything disastrous based on misinformation from me. Intuitively, it seems like a bad idea to me, so again, let me try to substantiate this before you try it. If anyone can confirm/disprove what I've written here, please do so, you certainly won't hurt my feelings.

I have seen some makers spinning heads onto their pins, but cannot recall whether or not that was limited to the handle pins. We do similar processes here at work and it seems much more controllable/repeatable than peening.

I do not have a bushing in here, just to clarify for those who may be unsure.

I thought there could be a possibiliy that the bushing would not swell enough to bind the blade, but I wasn't sure. The thing to do would be to alter the bushing diameter, or the hole it is going in - in the blade until you have a .001 to .002 clearance. Then when you peen, peen until the pin starts to swell, and when it starts to push the bushing out you may be able to control the blade friction by this. Just work your way up until you get the desired friction, because I'm sure that if you keep peening you will get some enlargement of the bushing inside the blade hole. From what I can tell, there is no need for a shim in between the liner and blade, because the liners are going to seat firmly against the bushing anyway, in order to keep it from trying to rotate. I may be wrong, but this is the best I can see this in my head.

I ground a piece of aluminum (in order to not damage anything because it is soft) in a wedge shape and inserted it into the liners right behind the pivot and blade. I drove this down into the space with considerable force from a hammer. I had to do this three times, because my alumium kept being altered by the harder 410SS liners. It did make a good bit of difference. This leads me to believe that the pin is not swelled, and that maybe the liners had seated up against the blade - further than I thought they had gone. I'm still not sure about that because I have the .010 gap up top near the spring. The blade and the spring are ground the same.

The blade regained its snap in all three positions, the most imprtant to me is the one where it is at full open and it snaps to stop at full open. The second most important to me is the closed position, where the blade seems to suck down in between the liners like a magnet has hold of it. The closed position is working, but not as good as I would like. Again, I still have binding apparently. I am much happier with the clearnace I apparently created because it was - as they say - a nail breaker to begin with.

The only thing that concerns me with putting lapping compound in is that it will remain inside and I won't be able to get it out. This will create issues down the road when it continues to work and I start getting too much clearance (I assume this would be the case).
 

JC in SC

Well-Known Member
Sorry for muddying the waters so-to-speak with regards to using bushings. My intent was to discuss how using bushings might help avoid the tightness you are experiencing. I see now that I inadvertently implied that you are using one, which I knew wasn't the case. Again, sorry for the confusion. I think your aluminum wedge method makes more sense than twisting the blade and might yield better results. The other nice thing about a bushing is that by leaving it 0.001" taller than the blade thickness, you built-in relief to prevent the liners from binding the blade.

I would avoid lapping compound in a finished pivot. Even with an ultrasonic cleaner I don't think you'd ever get all of the compound out. As you said, over the years this would result in a sloppy pivot.
 

J S Machine

Well-Known Member
Sorry for muddying the waters so-to-speak with regards to using bushings. My intent was to discuss how using bushings might help avoid the tightness you are experiencing. I see now that I inadvertently implied that you are using one, which I knew wasn't the case. Again, sorry for the confusion. I think your aluminum wedge method makes more sense than twisting the blade and might yield better results. The other nice thing about a bushing is that by leaving it 0.001" taller than the blade thickness, you built-in relief to prevent the liners from binding the blade.

I would avoid lapping compound in a finished pivot. Even with an ultrasonic cleaner I don't think you'd ever get all of the compound out. As you said, over the years this would result in a sloppy pivot.

No hard feelings :) - I knew you understood, I was just clarifying that for anyone who may be confused. I was just going on about how I feel about the situation and what can be done to remedy it.

You are correct on the busshing being .001 wider. I forgot about that point too.
 

J S Machine

Well-Known Member
Here are pictures from last night.

Turning the pins in the lathe down from.188 to .094-
slipjoint132.jpg


Measuring the pin - I went to about .0005 over so they would be snug. With a reamed hole this wouldn't be necessary, but with drilled holes they tend to be a little bigger in dia.-
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Tapering the holes with a tapered reamer, and then further tapering with a small cone shaped diamond dremel bit -
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All that was left to do at that point was pin it together and peen the pins. Not a hard taske at all, just be careful not to hit the knife, be sure the pin is supported on the bottom without any part of the knife touching your anvil (or whatever surface you use). Hammer down until the pins spread. Be careful in the more fragile materilas like Ivory and fossil scale pieces. You don't want to peen so far you split wood or cause cracks. I've said it before, this stag seems pretty forgiving, but I know there are other materials that are not. Also pay particular attention to the pivot joint. If you haven't done so, do a little research on bushings vs no bushings and methods on how to get the fit right. One too many hammer hits here will freeze your blade and ruin your project. remember, nice and easy. Take your time. Check the pivot after each hammer strike on the pin.
 

J S Machine

Well-Known Member
And now the pictures you all have been waiting for. I present to you my first slipjoint :)

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Comments and criticisms are welcome. I 'm proud! There. I said it
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