flat bending

[thomjeff]

I have bend two flats with a jig a purchased from a list member and I'm not sure if they have come out OK. One of the sides on both receivers is not exactly vertical. The one side has a perfect 90 degree angle and the other side is slightly more than 90 degrees (the side splays out a little bit). Is this OK or do the sides need to be perfect?
Thanks!
thom

[Quarterbore]

Can you post pictures?

With the DPH, 555th, and AK-Builder jigs I have never had this problem but because your front and rear trunnions will help secure things along with the center support it probably would work if it is not too bad.

I would try to get some square stock and get it squared but without the jig it may be tough to do?

A photo would really help...

[thomjeff]

Here are a couple of photos from the rear. The jig I used is a version of the 555th jig. The flats are the AK Builder economy flats. The left side is not vertical. It splays out a little bit. Although the left side appears to have a bow in the photos, it doesn't. It is straight, it just isn't vertical like the right side. I'm hoping the trunions and the center support will pull it in. Also, I think the photos make it look worse than it is. What do you think? TIA.
thom

[Quarterbore]

Those are fine. You are building an AK not some funky black rifle that has super tight specs!

Really, those look great. I assumed you had much worse then that... I have built with flats that are like that with no issues at all!

[thomjeff]

Thanks for the reassurance. I don't have any experience building an AK, so I wasn't sure how "perfect" the fit needed to be. I'll proceed with confidence.
thom

[cntrailrider]

You're fine, absolutely. You can even bend them in a little by hand if you want. I've built about 10 using TAPCO flats on a home-made jig (from square tubing) my corners didn't look nearly as nice/sharp as yours.

The reason I mention bending it in by hand is to be sure your FCG pins & selector lever reach far enough over, to engage the right side. You don't want any 'bulges' top to bottom nor front to back

You might want to visit http://www.akfiles.com/forums/ gunsmithing and Build It Yourself forum. You'll find the answer to every AK question you can think of. Excellent resource, many experienced (50+ completed) builders

Good luck - AK building is ADDICTIVE

Steve in El Paso

[Davidfxs]

They look good to me. When you put the center pin and trunions on they will be drawn in. Good Luck and cntrailrider is right "AK building is ADDICTIVE"

[kochevnik]

What you are experiencing there is called 'springback'.

In metal bending physics, It is IMPOSSIBLE to get a 90 degree angle bend using a 90 degree angle jig. Springback is exactly what it sounds like - the metal 'springs back' after it is bent. Here is a pretty good technical description of how it works (you can even punch in some numbers and watch the metal being bent) :

http://www.steeluniversity.org/conte...eid=2081271346

What most 'real' presses do to make a 90 degree bend on steel is use a 88 degree die - then when the metal is released it 'springs back' to 90 degrees.

I would say your receiver will work fine - the trunnions and pins shoud pull it back in.