New Shadow 2 with new cuts inside

[venture]

9 hours ago, yigal said:

slide stop .-

:facepalm: must of over thought that one

Edited March 13, 2018 by venture

[Babis]

What if the shadow 2 is out of warranty can we make the relief cuts?

 

[SDD-UP]

I am a mechanical designer by trade (not an engineer) so take this for what it is.  In my opinion this frame cracking/breaking failure is most likely caused by A - improper heat treatment of the steel (too hard) and/or B - improper steel alloy selected (too hard/brittle for this IMPACT no matter how it is heat treated)

 

Removal of the top portion of the hole is a solution, but probably not the BEST solution in my opinion.

 

I think  CZ certainly has the resources to figure this out and come up with the right solution. 

[Babis]

So it has nothing to do with the material being thinner in that specific part of the gun because many shadow 2 have the same problem also my cz85 combat has the same crack at the same spot.

 

[SDD-UP]

Babis,

 

Only speculation on my part.  I do not own a Shadow 2 yet, but will go look at my 85 Combat.  How many  rounds through your gun?

 

It's not just the frame, but how hard/flexible is the pin?  If the force through the pin could be directed through the middle of the frame material instead of through the full length of the hole it would reduce the twisting induced in the frame and likely eliminate this type of failure.  There is limited space to do this and it is just one more possible solution.

[Babis]

The rsounds I 've shot through cz 85 combat are 7-8k. Maybe you are right about the solution but how can you know how flexible is the pin? Or if the hole is larger ( possible that ) how can  I make it smaller? The top of the hole is thinner than 75 just like the shadow 2 that's why it fails, thats why the next gens of shadow 2 have relief cuts at exact this spot.

[MsDV8]

On 12/9/2018 at 10:28 AM, SDD-UP said:

I am a mechanical designer by trade (not an engineer) so take this for what it is.  In my opinion this frame cracking/breaking failure is most likely caused by A - improper heat treatment of the steel (too hard) and/or B - improper steel alloy selected (too hard/brittle for this IMPACT no matter how it is heat treated)

 

Removal of the top portion of the hole is a solution, but probably not the BEST solution in my opinion.

 

I think  CZ certainly has the resources to figure this out and come up with the right solution. 

@SDD-UP I concur.  I’m going to weigh in as a metalsmith working in Sterling Silver and gold.  Metal crystals are usually large and move within a semi-ordered structure, but when metal becomes work hardened through processes such as rolling, drawing, milling and hammering (those reciprocating slides don’t hammer the metal do they?  ), the crystals break down into smaller crystals, creating more grain boundaries and these can become what’s referred to euphamistically in the jeweler’s world, as “log jammed”.  Even if a metal is properly annealed (heated to the point that the metal becomes softened again) if the metal is rapidly cooled, the crystals don’t have time to properly develop into an organized structure and tend to recrystalize into the smaller grains.  End result:  cracking.

 

Now having said that, with all this kerfuffle about cracking S2 frames, I decided to check my non-optic S2 and here is what I found.  I also compared it to the OR S2 and note that the OR S2’s come milled.  Am I right?  Do I have an S2 with a cracked frame?

 

 

Edited February 3, 2019 by MsDV8

[robertbank]

Sure looks like it.

[yigal]

yes 100%.

it's start like this  in all s2 guns in the club after 4-9k factory ammo. this is the first stage.

second stage:  r. side totally separates from the frame.  ~15k.  i checked  all of them every week to see the progress.

this shooters shoot now with  .1911 /2011 platforms.  now they over 20k.

[slavex]

the theories on why they have cracked forget one thing, Shadows made at the same time, aren't cracking. Same metal, same machining, although done on different machines, and same basic design and specs. The 2 has had all dimensions trued better than the 75 did, resulting in a tighter gun, but that shouldn't account for the cracks. I've looked at my 6 Shadow which have almost a million rounds through them, none are cracked. My practice gun is at 75,000+ rounds, no crack, and it's consecutively serial numbered to my match gun which did crack. There has to be a specific reason for this that we haven't figured out. Also, CZ clones have experienced this as well, enough that some have solved the problem the same way, cutting the offending ara out. 

[yigal]

14 hours ago, slavex said:

the theories on why they have cracked forget one thing, Shadows made at the same time, aren't cracking. Same metal, same machining, although done on different machines, and same basic design and specs. The 2 has had all dimensions trued better than the 75 did, resulting in a tighter gun, but that shouldn't account for the cracks. I've looked at my 6 Shadow which have almost a million rounds through them, none are cracked. My practice gun is at 75,000+ rounds, no crack, and it's consecutively serial numbered to my match gun which did crack. There has to be a specific reason for this that we haven't figured out. Also, CZ clones have experienced this as well, enough that some have solved the problem the same way, cutting the offending ara out. 

 nobody in cz engineers  don't understand why this happens ? 

to make drawings even teenagers can do. even i can do 

they can try to use theirs heads not only for eating.

[slavex]

Oh I am sure CZ knows why, and I understand that they won't share that info outside their management. But I still want to know why. 

The drawings are definitely not something a teenager could do, I studied mechanical drawing and drafting as well as engineering and have seen the new drawings compared to the old, many many things changed. 

The cafeteria at CZUB isn't bad, but they only eat in there for lunch lol

[yigal]

44 minutes ago, slavex said:

Oh I am sure CZ knows why, and I understand that they won't share that info outside their management. But I still want to know why. 

The drawings are definitely not something a teenager could do, I studied mechanical drawing and drafting as well as engineering and have seen the new drawings compared to the old, many many things changed. 

The cafeteria at CZUB isn't bad, but they only eat in there for lunch lol

they must add to their  menu  more vitamin b12

[muncie21]

On 2/4/2019 at 11:15 AM, slavex said:

My practice gun is at 75,000+ rounds, no crack, and it's consecutively serial numbered to my match gun which did crack.

In a typical batch manufacturing process, consecutive serial number may not be indicative of consecutive/sequential manufacture order.  Just that the engraving was sequential.

[slavex]

On 2/6/2019 at 3:04 PM, muncie21 said:

In a typical batch manufacturing process, consecutive serial number may not be indicative of consecutive/sequential manufacture order.  Just that the engraving was sequential.

 

oh I know that, normally, mine were done back to back by the same guy though, with frames pulled at the same time.