An Achilles Heel…..IZH46M

[Frank in Fairfield]

We all know about the cheap pot metal cocking shoe AA uses with the TX200 and ProSport.
We also know about the cheap screws used in the IZH46M grips.
What we did not know was the other cheap, pot metal parts used in the 46M.
Part #51.
The cocking linkage that retracts and compresses the piston into the chamber.
Last night at the Diablo Indoor 10M match in Bay Point, CA, I was starting my pre-match practice and, after firing three pellets, I noticed the cocking handle hanging freely from the pistol.
I tried to close it but couldn’t because the linkage was broken and was jammed into the slot where it normally resides.
I do not know if pot metal can be welded or not. (I will check with the Motörhead.)
A fellow shooter who is knowledgeable about metallurgy said it was poorly made at the factory.
I am sure I cannot get a replacement part.
If it cannot be fixed, I will be selling the grips, trigger, and several o-ring/gasket kits…

[Gwelo]

Unfortunate. 
How old is your pistol?  How many shots fired?

JB Weld?

[Madd Hatter]

You could always see if a machinest could make another one if it's worth it?

[Motorhead]

Pot metal CAN NOT be welded ... or really repaired to have structural integrity.  JB weld can certainly hold the pieces together, but doubtful to be strong enough in this situation / application ? 

[Frank in Fairfield]

Thanks Scott.
I that was the case.
Oh well.
Maybe I will part it out.

[Motorhead]

Grips .... if Large / ex large would be interested in ?

[Frank in Fairfield]

Yep

[mikeyb]

Are you certain the broken part is pot metal?

Looks like a piece of stamped steel in the photo? If steel then a TIG welding repair might be strong enough. I would not waste any time trying to repair broken pot metal in a high force area.

If that were my pistol I'd try to fabricate a replacement part from a piece of steel or maybe stainless steel.

Without more detail it looks like the part could be made from sheet stock. Only tools I would need are a drill press, an angle grinder with cutoff disk, a hand file, and time.

Simple tools made gun parts for hundreds of years.

Seems a shame to parts-out a nice target pistol airgun for just one broken part :-(

[mikeyb]

With the amount of force required in that #51 link it really should be steel.

https://www.gatewaytoairguns.org/GTA/index.php?topic=153475.msg155688851#msg155688851

Looks like Subscriber has all the linkage part dimensions modeled in CAD. If I had a CAD drawing or a CAD model I could import into FreeCAD I might be able to make you a replacement part?

No charge for time and material. I'd consider it a kind of Pay It Forward.  MAYBE shipping cost IF and ONLY IF the part worked correctly.

Certainly other folks closer to you might be able to make the part also.

[Frank in Fairfield]

I want to thank all of you.
I will try and take it apart and have the part welded.
Next door neighbor has a welder.
I don’t want to try and take out the rivets to remove/replace the part.

[HunterWhite]

I wouldn't think that steel would break like that. Steel usually bends in my experience.  Hardened steel may break but I would not expect that part to break. 
If you try to weld it maybe it will work.
Maybe it will destroy it completely. 
As it is Mike may be able to use the broken part as a pattern.

I think that your pistol seems like a nice one. Hopefully you can get it fixed. 

Hunter 

[mikeyb]

A quick test is to check if a magnet sticks. If steel and the neighbor has TIG welding experience that repair might work.

The part broke right in the middle of the relief arc. Could be a material defect or a stress riser from a sharp edge during stamping? If the part was stamped straight and the arc bent later this would stress the material. Outer edge of arc would be stretched and could have micro-cracked during manufacture? Maybe the steel was hardened and not properly tempered so it was too brittle?

Regardless, I think a piece of quality tool steel could be cut, shaped, and drilled while soft. I'd dress (soften/round-over) all the sharp edges to minimize any future stress risers.

There is a local metal supplier here that sells all their shorts and cutoffs by the pound. A piece of tool steel to make that part would be less than $1. I'm no expert on knife steels but I think they would have suitable raw material.

The part would likely benefit being hardened then tempered to be very strong but not brittle. That's about the largest part I could harden/temper without getting a proper forge. Would LIKE to PLAY with larger metal forging but don't have the time until I can actually retire ;-)

[miro]

This is a common failure of this model. The Soviet IZH-46 did not have such a problem, it has a lower force of the cocking lever and does not have that "deflection" that was made later on the Russian MP-46m. Usually such a failure occurs when the shooter strives to get maximum power and sets the piston to the highest air compression. Therefore, the first advice is to reduce the pressure in the cylinder by half a turn of the piston. In many sports clubs, this part - the connecting rod - is repaired by welding. On my IZH-46 pistols, this part is made by milling from magnetic steel. On forums, they recommend making a new one yourself from a wrench, its middle part fits well in size.

[miro]

Drawing of a modified part. I’m not sure that the detail must be so thickened at the place of deflection, in my opinion it may well be flat.

[Motorhead]

Great info Vadym !!!

[Frank in Fairfield]

I have many sets of o-rings/gaskets, additional rear and front sights for the IZZY.
Even broken, the pistol will not be sold for less than $400.00-$450.00 plus s+h..
That is Steve Corcoran furniture as well as the after market trigger and scope mount

[Frank in Fairfield]

Well, I took it apart.
My next door neighbor is a welder.
He says the part is cast metal and maybe cannot be welded.
He will try.
If not the gun will be parted out:
Steve Corcoran grips.
AV Trigger
Many o-rings and seals
Extra sights…

[Airnut]

That would be a shame to part it out over a simple to make replacement part!
But thats just me.

[Frank in Fairfield]

Broken
Welded
Operational.
Note: I had to replace the piston seal. If you have never done this have patience and cuss a lot:🤬

[mikeyb]

Nice!
Depending on your welder's skill and the filler alloy he used that repair might be stronger than a factory new part.