Modifying pistol receiver back plate cover for Lage, ACE or Stormwerkz hinge

[travinh]

I have an extra gen 1 Evo pistol back plate. I would to modify it, so I can mount either ACE or Stormwerkz hinge to use with KAK. Has anyone performed this type of modification?

Thanks,
Cal

[Randoogler]

I have an ACE folder on mine but it's mounted using the Lage adapter backplate. Do you think there's enough thickness on the stock end plate to mount a folder securely?

[akuser47]

Someone has done it but I don't know who it is that did it.

[OhHey1]

Adding a fairly large, metal stock to the rear of this small polymer gun might make the balance of it feel weird. If you just want a solid folder, get the Zhukov.

[travinh]

Hi John,

Look great!

My idea is different than your. I think it should work. Worst case, I will get the back plate from ACE or Lage.

I ordered the Stormwerkz hinge and adapter for AR buffer extension tube. I will drill the holes when I receive my hinge. Once the hinge is installed, I will add J-B weld to the nuts area to strength the structure.





Stormwerkz hinge and AR adapter.

I was able to mill off the sling loop and measure off for the Ace folding mechanism so it would seat back flush on the scorpion plate.



I also had to remove some material from the rear because the heads of the screws were larger diameter than the factory cutout and also drilled the hole for the plate release.



As was asked in the OP, the material where the screws were placed IS very thin.  It doesn't feel weak, but I am going to add 1 or 2 more screws to make it stronger.  I may also use epoxy between the Ace folding mechanism and the scorpion backplate.  I don't see how it would hurt anything if I did.   I just don't feel comfortable with just the two existing screws that came with the ace folding mechanism because it is so thin in that area.  The new screws will also need to be tapped and countersunk from the underside so it won't affect the plate from sliding on and off the rear of the pistol.

Another note, you can determin whether it folds to the right or left by which direction you mount the ace folding mechanism.  I'm going to fold mine to the right.

But this is essentially what it will look like when finished.  I just have to see if I can find a tap/screws locally and order the pignose.

[travinh]

Yes, the nuts sit flush.

I really like how you chose square nuts to fit in the slot on the underside.  I hadn't thought about that, but if you can get the nuts to sit flush so you'll have enough clearance to slide it on and off the back of the pistol your design should have no problem.

[akuser47]

Nice work I think John is the one I had originally seen looks familiar. Great work though both look like they'll hold up fine.

[BlahX3]

I'd like to use a VZ58 folding stock on my Gen 1 Scorpion when my form 1 comes back, any suggestions?

[akuser47]

Great work regardless

[Lage Mfg]

We have the largest selection of different stock configurations than any other manufacturer for your CZ EVO Scorpion.  11 different stock configurations are available.

We have fixed stocks of different lengths, left folding, right folding, compact and slim K-Stocks, fixed and folding AR 15 stock adapters and fixed and folding shooting brace adapters. All folding stock configurations are designed to allow the gun to be operated and fired with the stock in the folded position. Individual components are also available, such as stock adapters, folding mechanisms and stocks for your own custom application. Additionally, all of these stocks will fit on a gun that has an ACE Rifle Stock patterned mount (two #10-32 mounting screw holes spaced 5/8" (.625") apart and 1/4" (.250") pocket in the center).

These are in stock and ready for purchase.  You can order on-line from our webstore at www.max-11.com.

Dealer pricing is available. Please e-mail sales@max-11.com for pricing. More pictures are available on our website, www.max-11.com

[BlahX3]

Thank you again for the compliment akuser47.  It is appreciated.

I'd like to use a VZ58 folding stock on my Gen 1 Scorpion when my form 1 comes back, any suggestions?

Should be do-able.

But you'd probably have to fab a piece to go between them so the backplate would attach to the adapter, and the adapter would go to the stock.  I only see 1 large screw hole in the VZ58 stock.

Or, you may consider this little gem from Lage manufacturing:

Scorpion- K-Stock, Right Folding, 5 Deg. Cant

Now that's way better than my idea.
Thanks!

[travinh]

Completed my back plate modification.








If you have the new gen2 back plate, the modification is very easy. Below is the picture of my gen 2 back plate. Just drill 2 holes by using 11/64 bit and then drive the #10-32 screw thru the hole to create the thread. No thread tap is needed.


DON'T buy the Stormwerkz standard hinge (picture below). It does not have enough room to accommodate the AR extension buffer tube adapter when folding.

[travinh]

I want to have it folding to the left side, so I can shoot it while the KAK brace is in the folding position, but I see two issues. The KAK brace will block the charging handle and handguard grip. I turned my AR Stormwerkz hinges upside down, so I can have it folds to the right. The AR pistol tube block about 1/4 of the cartridge ejection port. I hope that I will not cause ejection problem.

Thanks for heads up about the stormwerks hinge.

It looks like you did a really nice job on the milling.  It looks factory.

Here's how mine turned out with the Ace folding mech.

Only downfall with it folding left is you can't charge it with the stabilizer brace folded.  Though I have the OEM charging handle installed on the right side so I have the option of using either right or left handles and I don't have any problem with cocking it like you would an AK or SKS.

But I thought it was worth noting.

[travinh]

Hi John,

Took my EVO 3 to the range today. I fired 30 rounds with the pistol buffer tube folded. No fail to eject at all even though the pistol buffer tube appears to block more than 1/3 the ejection port. Many cartridges hit the buffer tube, but they bounded upward and drop about 4 feet away. I will leave my KAK (on order) to fold to the right side cause there were no ejection issues.

Cal

Yes, it does cover some of the ejection port, and is why I flipped mine over so it'll fold to the left.  I am interested in hearing from you as to whether it does cause ejection problems or not.  If f it doesn't, I prefer to flip mine around to be honest. 

Since I have the HBI charging handle on the left, and the OEM charging handle on the right, my gun can still function completely with it folded left since it's set up to be ambi anyway. 

Also, where the HBI charging handle protrudes more, if I have to leave the folding mech on the left, I may switch the HBI handle out over to the right side so it'll be easier to reach over or under the frame to get to, but if the gun cycles alright on the right, that would be great.

Not that I plan to shoot it with the brace folded, but would be nice to know if it can or can't.

[rogueshot]

Travinh: Nice work. You should definitely modify gen 1 back plates for folks.....I would definitely send you mine for the AL bar stock addition, drilling and square nuts to be able to mount the Ace hinge.

Completed my back plate modification.








If you have the new gen2 back plate, the modification is very easy. Below is the picture of my gen 2 back plate. Just drill 2 holes by using 11/64 bit and then drive the #10-32 screw thru the hole to create the thread. No thread tap is needed.


DON'T buy the Stormwerkz standard hinge (picture below). It does not have enough room to accommodate the AR extension buffer tube adapter when folding.