Tang pins...again

[7Cain]

Yes, but you can always make the handles softer than the tang pin.

True, you can make the handles softer than the tang pin, but there's no need.

So in terms of hardness, the hardest would be the blade, then tang pin, and last the handle. Even with a softer handle, you'll still have to deal with the impact stress of the handle hitting the tang pin, and the tang pin transferring that stress to the blade. A softer tang pin will cushion that stress a bit to avoid stressing the blade.

I don't see any good reason to have the tang pin and handles differ in strength, they are going to be smacking each other and with a difference in strength this means something has to give or bend either the tang pin or the tang pin cups. Sure the handles and tang pin can be softer than the actual blade steel if you want more cusion from impact, but I wouldn't think that it is required. A good example of improper strength relationships between tang pin and handles are found in the cheaper balisongs, for example BM's econo line from the past. The tang pin cups in the handles of my 239 grew deeper every time I manipulated it. It only took a few months before the cups where so deep that the tang pin needed to be larger in order to lock open properly.

OK, here's where I have a problem with the way BM makes the tang pins. If you are able to rotate it, then it's not 100% tight against the blade, and there's a minute gap between the tang pin and the blade. The will cause the tang pin to bounce against the blade's tang pin hole. In my books, that's a bad design. Using the freezing method, you'll get a as perfect to 360 degree mating, with little to no gaps as possible, for maxium friction lockup, for all 3 axis (no sliding up or down, no rotation, and no wobble). Plus there would be no need to peen. Peening the tang pin into the blade, ala the Jag, causes too many issues with the handle relationship you and Eric were referring to.

I should have clarified my statement. My tang pin does not spin freely or easily, it had to be forced with a clamp. And even if you use the freezing method as you stated there is no chemical bond between the tang pin and blade steel, and I would still be able to turn because it is round, the only way to fix that is to either shape the tang pin (oval would work) or mill it out of the blade stock. That is just the nature of the beast.

I have not made my own balisong yet, so I cannot say that I am an expert on this matter. It just seems logical

 

[Eric T. Maier]

As long as the tang pin and handles are made from decent material like stainless, there will be no apreciable wear. Flipping the knife can only produce so much impact force based on the weight of the handles. Once you get into good quality metals the wear problem is not really an issue. I've been using 303 stainless for both and have had no problems. To fix the tang pin in the blade I will drill a hole the exact size as the pin stock or make sure the pin is the exact same size as the hole in the blade. To fix the pin in the blade I simply center it and peen each side with a good smooth faced flat hammer. Flip it over every few blows and check to make sure you're hitting it square. This should be all that's required. I've never had one fail or wear any major "divots" on the handles.

Mer

 

[tonyccw]

Originally posted by 7Cain
True, you can make the handles softer than the tang pin, but there's no need. I don't see any good reason to have the tang pin and handles differ in strength, they are going to be smacking each other and with a difference in strength this means something has to give or bend either the tang pin or the tang pin cups. Sure the handles and tang pin can be softer than the actual blade steel if you want more cusion from impact, but I wouldn't think that it is required.

At least you and I agree in the tang pin being softer. Here's where I stand on the handle to tang ping relation. The reason your handle wore out so fast is that the difference between them were too great. Typically the case with cheap cast handles. If, and a big if, you can cut out the tang cup exactly/perfectly, then there's no need for the handle or the tang pin to be softer. It will ensure that the bali locks up in both the open and closed position for a very long time, as there will be very little wear, if any wear.

We all know that the gap between the handles is what provides the tension to lock the handles open. And that gap is defined by the tang pin. Problem, and Eric can vouch for this, cutting the tang cup is probably the hardest prt of making the handle. Too little and the gap's too wide. Too much and there's no tension. It makes or breaks the fit. I went with the option of a softer handle (by say a few rockwells) in my design to allow the handles a chance to "seat" themselves. If done properly, they should not wear out within a month. See futher comments on the tang pin below.

And even if you use the freezing method as you stated there is no chemical bond between the tang pin and blade steel, and I would still be able to turn because it is round, the only way to fix that is to either shape the tang pin (oval would work) or mill it out of the blade stock. That is just the nature of the beast.

Here's where I differ from your experience. Properly done, the freezing method will provide full contact of the tang pin to the blade, which means every surface area the tang pin comes in contact with the blade. The smoother the walls of both surfaces, the more contact is available. This contact is futher pressurized by the expansion of the oversized tang pin in an undersized hole. You should not be able to turn the tang pin with much of anything. If you do, you're destroying the mating surface, and the tang pin will start to float.

I have not made my own balisong yet, so I cannot say that I am an expert on this matter. It just seems logical

Your arguments are sound, and they make perfect sense. I'm digging deeper into what I think would make the perfect tang pin. In reality, this is one of the areas that forced me to stop making my own bali. I couldn't get the damn thing to mate well. It looked good on paper, but proved much harder to execute.

Tony

 

[7Cain]

I agree with your re-iteration. I was unaware that you were referring to just a few Rockwell measures in difference (seeing as that is not a significant difference but enough to soak up the shock you're talking about), I thought you meant at least 10 measures. A few rockwell differences would be as insignificant as putting a fuller on a 7 inch dagger (metaphorically speaking).

I too have a preliminary balisong in the works, granted it is still only on paper but I have a full schematic of it, I call it "The Life Key". When I can afford to purchase the minimum order of some titanium stock I will begin the construction of it. Damn that is going to take a while because I only work with a hand file and a dremel tool right now. Oh well, my throwing knives are almost finished so that will free up some time. Thanks for listening

 

[7Cain]

Eventually, I'd like to make/purchase a bali constructed completely from Titanium. Beta Ti has come along and though I have no experience with it as a blade steel it looks good on paper, and the properties sure sound good! Just think, a bali that would never rust! (not that my 42 has ever done so) I think I'm just a Ti nut

I'm creepin up on you again Tony

 

[blade_420]

I love that I hang out with a bunch of guys (sniperboy ) that can appriciate the asthetics of a good tang pin, and even dream towards " THE PERFECT TANG PIN "

Maybe someone will eventually answer my question:

What is the perfect blade/handle weight ratio.

All I've ever got before is basically, "personal preferance"

But still I wonder.... Is there a perfect relationship? or is there at least a workable ratio to look for?

Hmmmm.... I wonder......

 

[tonyccw]

Originally posted by blade_420
I love that I hang out with a bunch of guys (sniperboy ) that can appriciate the asthetics of a good tang pin, and even dream towards " THE PERFECT TANG PIN "

It's not funny to make light of a man's dreams... Bali's at 10 paces, sunrise tommorow.

 

[blade_420]

I'm there, you're done...

 

[GTAsteel]

This thread has definetly been more interesting that I ever could have hoped... We have brought up, I think some interesting information and started a fight... grovy

Anyone else got anything to add or gauntlets to drop?

Thanks guys

 

[hogman]

I'd just like to clear up the technicalities here by clearing the record and saying that I like to have a tang pin on my bali.

 

[tonyccw]

Originally posted by hogman
I'd just like to clear up the technicalities here by clearing the record and saying that I like to have a tang pin on my bali.

Thanks Hogman, this thread was starting to get a little thick

 

[7Cain]

Does anybody seriously think this got heated even in the slightest? I know I enjoyed our discussion, it was a fun but brief moment of expostulation, however I don't think we got too thick.

Tony, you are aware that I respect your opinion and do not wish to be serious in an argument with you, right?

I thoroughly enjoyed our moment of difference It allows us all to see a multitude of opinions and ideas! If we cannot share that, then what is this forum for? I personally have no problems with what anyone says here at the forums as long as we do it with good reason and remain civilized about it. Anyway, thanks guys for being part of this subject, I enjoyed myself immensely!

 

[tonyccw]

Originally posted by 7Cain
Tony, you are aware that I respect your opinion and do not wish to be serious in an argument with you, right?

What, did my New York City attitude show through my posts?

I thoroughly enjoyed our moment of difference It allows us all to see a multitude of opinions and ideas! If we cannot share that, then what is this forum for?

Hear, hear!!! I too always enjoy a educational debate. Never too old to learn something new. It's just that for a debate to be really worthwhile, both parties needs to contribute ideas. I firmly believe we all have something to share.

I know I personaly still have a lot to learn about the physics of the balisong, as well as the technical/mechanical understanding/execution necessary to make the balisong a reality. As the old saying goes, back to the drawing board.

 

[7Cain]

What, did my New York City attitude show through my posts?

Laf I was not worried, I sensed the playful antagonism of your posts but never took it as an effort to be confrontational. The opinion of other members however seemed to be that we had an argument going on, either that or we where nit-picking too much (NEVER)

I know I personaly still have a lot to learn about the physics of the balisong, as well as the technical/mechanical understanding/execution necessary to make the balisong a reality. As the old saying goes, back to the drawing board.

I'm always happy to be a member of this forum!! You guys rock!

 

[sniperboy]

just wanted to chime in and say that I have met a friend who works in an oil rig who has ACTUALLY done this nitrogen fittin with tang pins and handle pins.. very awesome

 

[Blasto]

So, have there been any tang pins made square instead of round?? I would imagine that the stress on impact would be much less, seeing has how you're changing the striking area from the edge of a cylinder, to one big flat side of a block. In fact, I can't see a reason why you wouldn't use a square pin. So, is this a valid concept, or am I the fool I've always imagined myself to be?

 

[tonyccw]

Originally posted by sniperboy
just wanted to chime in and say that I have met a friend who works in an oil rig who has ACTUALLY done this nitrogen fittin with tang pins and handle pins.. very awesome

See, see. I wasn't making this up... WE HAVE PROOF!!!!!! Yeah!!!!!!!!!!

Now, if I can dig out my old notes, maybe I can ask him(her) where I went wrong...... Heck I should dig out my old notes for Mer to do the handles, Orchyus to do the blade, and your friend to put it all together....

 

[tonyccw]

Quick answers this time.

Square hole the size of tang pins are very hard to make. Perfect cornors require expensive equipment. And you need perfect 90 degree cornors to maintain perfect 360 degree mating of materials. Rounded corners could be easier, then you're introducing the problems associated with radius (radii).

On impact to a round pin, the contact may be smaller, but the force transferred is the greatest. Any degree of impact is absorbed by the whole pin. Best example in reverse is the baseball bat; all that stored energy is released at the contact to the ball, for the greatest power delivery (given the right angle).

For absorbtion of stress, a square pin can only provive 180 degrees of resistance (the two opposite cornors), where as a round pin maintains 360 degrees.

Waiting now for the anticipated aftermath....

 

[penguin_2000]

Originally posted by Blasto
So, is this a valid concept, or am I the fool I've always imagined myself to be?

I think, therefore I am
-Descartes

..., just kidding.
Anyway, about the square pin, I think it would be <b>difficult</b> to do right, but I think it would result in a better tang pin. Tony's comments are mostly true, but I don't think the pin would have to be perfectly square--I believe the point is to have a large surface area for contact; the 90 degree corners are not necessary. Actually, 90 degree corners would make it the handles incur almost infinite stress at the corner.

 

[GTAsteel]

Tony the validity of your freezing metod was never in question for me. It's possible. I just thought that it would be easier for me to do the opposite and heat the blade, expanding the hole, vice freezing the pin and shrinking the pin.

As too a square pin, I think it would be harder to do, baised on equipment required to make such a small, square hole, and if it wasn not perfectly alined with the pin cups, both open and closed the handles would end up stricking on a corner.

The search for the "perfect" tang pin continues...