Spyderco Mule ZDP-189: problem

[yuraelektra]

Hello, friends!
In the camp Spyderco collectors in Russia, confusion reigns :eek: . One after another, in the manufacture of linings on the handle were broken two Spyderco Mule ZDP-189 . Efforts have been made very small, no more fracture pencil. Other collectors are afraid to touch their Mule-zdp :D .
http://translate.google.ru/translate?js ... ry_state0=

[yuraelektra]

pictures

[The Deacon]

The same thing has happened to a few people here in the USA and was reported in THIS THREAD.

[gaj999]

I tossed mine onto the garage floor, a flattish landing from 3-4 feet up, and then put a handle on it. At one point it was vised up and I was sanding the handle gently with strips of sandpaper. There was some flexing going on, but not a lot. I saw no breakage or cracking. I was careful to get the vise on the small part of the tang that extends past the end of the handle.

I am, however, having a very hard time getting it really sharp and am wondering if the edge could be fracturing at 20 degrees included because it's overly brittle. I can't seem to get it any sharper than it came from the factory. A 30 degree micro bevel didn't work either. At some point, I'll probably go to a bigger 30 degree bevel or even a 40 degree angle to see what effect that has. I'd expect it to help if that's the problem.

Right now, I'm letting it sit in the drawer for a while to see if it gets sharper that way. :D

Gordon

[MCM]

"I can't seem to get it any sharper than it came from the factory"

I am sure I cant either!
Both mine came hair splitting sharp!

[noddy]

Is there any idea if this is a generic problem with Mules and their HT - isolated hiccups - or is it just ZDP189 needs to be laminated at that scale, hardness and relative thickness?

[The Deacon]

Is there any idea if this is a generic problem with Mules and their HT - isolated hiccups - or is it just ZDP189 needs to be laminated at that scale, hardness and relative thickness?

I'd say it mostly the last of those, or rather that, at the size and hardness of the ZDP Mules, they need to be treated more like a ceramic blade than like machetes. Seems to me, since the purpose of the Mules was to test a variety of steels on a given platform, some of them are bound to be less suitable, suitable for different uses, or require different treatment, than others.

[gaj999]

"I can't seem to get it any sharper than it came from the factory"

I am sure I cant either!
Both mine came hair splitting sharp!

Well, this is the first knife I've ever owned that I couldn't get much sharper than it came from the factory. Mine would shave, but certainly wasn't hair splitting sharp.

I wonder how much variation there is from blade to blade?

Gordon

[freeman7]

I think Paul hit the nail on the head. The Mule project was not meant to produce a fantastic series of perfect knives. Rather, the idea was to use different steels in essentially the same knife pattern so that we, ourselves, could experiment and see just how the steels differ from each other.

[demtek9]

I think Paul hit the nail on the head. The Mule project was not meant to produce a fantastic series of perfect knives. Rather, the idea was to use different steels in essentially the same knife pattern so that we, ourselves, could experiment and see just how the steels differ from each other.

I don't think they should crack like that when you are putting a handle on them. That was the other part....let users make thier own handles. That looks a lot like the fracture lines you would see on ATS-55.

[The Deacon]

I don't think they should crack like that when you are putting a handle on them. That was the other part....let users make thier own handles. That looks a lot like the fracture lines you would see on ATS-55.

I'm sure some folks have successfully put handles on their ZDP Mules, so perhaps the operative question should be "what did they do differently from the folks who failed." I see the Mule program is something like Beta software. You are, in essence, the "R&D" department.

[Padawan]

Without knowing the full story, my only guess would be that the broken knives were placed tip-down in a vice while the handles were being installed, and enough pressure or torque was put on them to generate a fracture.

Regardless of what caused the fractures, the fact that they have occurred in a number of these knives seems to provide a compelling argument for the use of laminated ZDP189/420J2. I've always felt that the laminated steel was an excellent compromise that not only provides the benefits of both steels with almost none of the drawbacks, but also (theoretically) reduces the cost of the knife.

[npueppke]

Judging from the fracture pattern the edge of the knife was probably whacked against something (like a cutting board), or they were used really hard in cutting somehow. The highest moment (torque) develops right where they cracked. Pushing back against the edge causes the region under the spyderhole to experience tensile forces, which probably opened up some existing flaws in the steel which could have come from anywhere-either they're inherent in this hard ZDP or they were caused by misuse or by machining.

If the knife was put in a vice and somehow bent you would think that it would snap clean in half instead of just cracking below the hole. I don't think putting a handle on the knife should cause it to fracture like that, I think it was probably used to chop with.

[alexvzin]

All knives was broken by hands, without vice. First user has made G-10 handle and try to check, how tightly scales ajoined to the handle. He apply a soft affort by hands, trying to bend a knife, and blade has broken. Other user has not believed in it, and try to do the same with his ZDP Mule..... with the same result. He said, the pressure was no more then to break a pensil. Than he make the same test with ZDP Stretch. He apply much more higher pressure, but knife has sustained. Stretch blade have the same thickness, and approx. the same geometry as Mule.

Is it normal? All ZDP Mule owners in Russia are now afraid even to breathe on them. :)

[The Mastiff]

He apply a soft affort by hands, trying to bend a knife, and blade has broken.

You don't try to bend steel with the same pressure you would break a pencil with, unless russia has super, extra huge , specially engineered space pencils.

My suggestion would be to not try bending ZDP. Lesson learned.

High carbide fraction steels at high hardness (RC64-65) aren't meant to be bent. Or chopped with, dropped, or twisted coming out of cuts either. It's really only common sense. Think of it like a high quality file, or drill with tungsten carbide .

BTW, there are steels much more brittle than ZDP. Much, much more.

If this was a $1500 chefs knife the buyer would probably already have known this to begin with. Sal has made the steel from that knife affordable to people who don't have the knowledge or training to know what they are doing. These cases of operator error don't surprise me at all.

Sal, please don't use these examples as a reason to lower the hardness in future Spyderco knives, not just ZDP either.

[yuraelektra]

All ZDP Mule owners in Russia are now afraid even to breathe on them. :)

Yes!
I do not know what to do.
Try to break? I feel sorry for the knife! Do not break and make the handle? I do not need a knife, which can be broken arms! :mad:

[The Deacon]

Yes!
I do not know what to do.
Try to break? I feel sorry for the knife! Do not break and make the handle? I do not need a knife, which can be broken arms! :mad:

Then the best thing to do, if you have one which is not broken, would be to sell it to someone who would appreciate it for what it is, rather than being upset by what it is not.

[yuraelektra]

Then the best thing to do, if you have one which is not broken, would be to sell it to someone who would appreciate it for what it is, rather than being upset by what it is not.

Sir,
I can not sell my Spyderco, I'm a big fan of Spyderco :) .
Here http://i2.guns.ru/forums/icons/forum_pi ... 382960.jpg
part of my collection, now more knives.
I am very concerned about this unfortunate incident with my favorite knife .

[noddy]

You are, in essence, the "R&D" department.

... erm .... I can't see that argument flying far :D :D :D

[alexvzin]

You don't try to bend steel with the same pressure you would break a pencil with, unless russia has super, extra huge , specially engineered space pencils.

Russian pencils is absolutely the same, as American pencils. Both made in China. :D