Slipjoint making?

Kosa_PL

Kosa_PL

Joined
Aug 25, 2013
Messages
1,220
Hello guys,

From some time I was thinking about to start making slipjoints.
And maybe you can help me with this?
I don't know exactly how to start with this, mostly in case of spring.

Elmax 2,5mm / M390 2,3mm would be a nice steel for blade and spring ?


Cheers,
Konrad
 
And somebody know, maybe the 80CrV2 will be good for slipjoints?

I have 2 sheets of this steel :)
100cm x 120cm 2,5mm thick :D
50kg of steel...

I also think about to use ATP-641 to prevent decarb.

This steel is hardened in 740-840*C range.
 
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Pretty much whatever steel you like, will work great for slipjoints.

80crv2 seems to be more geared toward larger choppers that need toughness, but that's just "my perspective".


Don't overthink it, although if you want to geek out on it, consider that traditionally, slipjoints are small thin blades, that see a lot of day to day work. Decide which factors matter for that scenario to you, if you're really intent on picking some "optimal" steel.

People sweat thru their pockets also, so consider the customer. Will your customers take care of a carbon blade in a more rust prone environment? I wouldn't want to put 52100 on one of my slips, because as great a steel as it can be performance wise, it starts rusting if you look at it sideways.


Me I use W2, damascus of 1084/15n20 typically, or AEB-L, which I recently switched to from D2.


IMHO high toughness steels will be a waste of money and effort on a traditional style/size of slipjoint, and probably wont perform as well as steels with fine edge stability. Daily users from my perspective benefit more from ease of sharpening, over extreme holding of difficult to sharpen high alloy steels, but I prefer frequent touch ups and a keen edge over something that holds a "good" edge for a long time.


Whether or not you agree with that, is of course, completely up to you.
 
The slipjoints i make (for me and friends) i make with carbon steels, but if disregarded they could actually develope spots of rust.
Think kitchen knives steels, thin and with a stable edge.
For my last ongoing build i selected 1.2519 (tungsten steel) for the blade and 1070 for the spring, because the latter will cooperate more readily to go down around 48-50 hrc.
 
Hello again ,

What steel from mentioned will be also good for a spring ?

M390
ELMAX
N690
AEB-L

What you suggest for liners/bolsters ?

And just started to making rise/fall indicator :)

Also I thinking about to use on my slipjoints a Nylatron GS 0,25mm washers.
 
Hello! From the steels you've mentioned the most corrosion resistant is n690 (I think) so I would choose that one for spring and liners. But if you consider other steel, than a simple 420 stainless is the way to go for both spring and liners.
For blade, a stainless steel like m390, elmax or n690 3,5mm+ would be fine.
Show us some drawing. Really like your work and attitude so most certainly will buy one of your first batch of slipjoints.

Best regards!
Hugo.
 
I use 410 stainless for liners and bolsters and pins when doing stainless, but you can use anything you like for liners/bolsters. Brass, bronze, mild steel, silver, gold, titanium, whatever. I use the same material as my blade for my spring typically.

I don't use washers, and don't like seeing a gap they usually create. They are unnecessary IMO, but I relieve for clearance to make sure i don't get scratches from the liners.
 
Nylotron GS will be good in liner/frame lock ?

Because I got a nice amount of nylatron...

FXydeF.jpg



I ordered 10m x 20mm strips 0,25mm and 1,02mm. And I got 28m of 1,02mm and 30m of 0,25m o.O
 
Your spring needs to be longer. Also the geometry of the tang when in the closed position is wrong. It will not hold the blade closed very well and will not snap closed at all. Otherwise it looks good.
 
On the blade, where it contacts the spring, one corner is radiused and one is fairly square. I haven't made that many slipjoints, but found that only a small radius is needed, equal on both corners- maybe one of the more experienced guys will chime in on this one. The totally rounded corner won't keep the blade closed.
 
Also the back pin i would better center in the handle...it's the pin that keeps the butt closed, against prying the liner apart from the spring's little "tail". You don't want pocket lint catching gaps near the butt and nearing the pin to the center helps
 
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The new design looks much better mechanically but there are two issues that I would be concerned about. First, you don't have much clearance between the tip of your blade and the spring. I suspect it will hit when it snaps closed. And second, it looks like you have some fairly sharp corners in your spring where it goes around the 2mm pin. You'll want to blend those out to minimize your stress risers. If you make that semicircular piece into more of a long smooth lump it will also be much easier to do finish work on.
 
Texaswade got it right, also remeber the spring stiffness comes from its height, way more than stock thickness.
In this case i'd probably move the center pin backward 4-5mm. Along range spring will help when tuning.
You could always skimm the spring to lessen the stiffness but doing this too much it would bend awkwardly, adding difficult to get flush in the 3 position. Another option is giving only very few preload, but it is not a straightforward method since it is very easy to end too stiff or too soft....too little range to play with.
 
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