Blueprints for a respectable solid AK bend jig?

[yari]

Used to live in sb had a lady in Santa Maria for a few years.

[yari]

Kc what the he'll do I want made of ti? Lol honestly couldnt tell you anything. Besides firing pins what else do people really use it for in the gun industry? I've heard of the odd ball frame here and there.

[kcstott]

It used more just as a gimmick then anything else. It really is use just to get someone to buy the part and nothing more in a lot of cases. And people will pay through the nose for some gizmo made from TI just because it's Ti.

I've seen a full bolt action receiver made out of TI, Obviously firing pins, Scope rings and bases. I just have a severe distaste for that material. I had to set up two CNC machines. One that made TI knife blades the other made the pomels for the knives. My thing with TI is it's not worth the weight savings. Unless you're building air craft or aerospace parts it ain't worth the expense. Obviously my opinion is biased so take it with a grain of salt from a guy that had to machine this stuff for closes to ten years.
Don't get me wrong though in the correct application it's great material I think it's just to buzz wordish even still today. We made a Knife blade out of the stuff just so we could say "solid Titanium" which also meant you knife was an over priced piece of junk. It won't hold an edge, it a pain to sharpen because it's soft yes soft Titanium is soft compared to tool steel. it's also springy as hell and doesn't conduct heat worth a darn so your cutting tool soaks up all the heat and it goes dull fast. I guess you can see where my distaste for the material comes from. Proper application and I'm fine with it.

Now I will confess that I have been thinking about a stainless AK. bead blasted flat and left that way. Stainless rivets, stainless everything. That would be a hell of a lot of work.

[kcstott]

Ok to the OP.
I'll take some measurements tomorrow and post them. But what I'd also do since you are thinking of building this. I'd build the extra punch so you can press 1.5 mm flats. as well.

The pin holes locations and clearances you can figure out from a flat.

[fabguy]

That is some beautiful machining. I bet you have several hours and then some, just in the lower die. Do you use a press to bend? I have brake that would make quick work in bending the flats with that jig of yours.

great job.

[hawkeye]

Ok to the OP.
I'll take some measurements tomorrow and post them. But what I'd also do since you are thinking of building this. I'd build the extra punch so you can press 1.5 mm flats. as well.

The pin holes locations and clearances you can figure out from a flat.

Sweet! I'll start getting ready to machine this thing when I get the dimensions from you. I've got two machinists willing to help me through this.

[tujungatoes]

Sweet! I'll start getting ready to machine this thing when I get the dimensions from you. I've got two machinists willing to help me through this.

You sir are a masochist. Curtis' flat bending die is the deal of the century at $170.

I hope you're doing this for the enjoyment of the process, cause you sure aint gonna save money. Good luck, and let us see the finished product.

[yari]

If you have access to a machine shop maybe look at getting milled receivers instead of a punch and die made? Just a thought.

[kcstott]

If you have access to a machine shop maybe look at getting milled receivers instead of a punch and die made? Just a thought.

Good idea, Too much work. I've thought of it an d unless you had CNC with a good fixture good luck

You sir are a masochist. Curtis' flat bending die is the deal of the century at $170.

I hope you're doing this for the enjoyment of the process, cause you sure aint gonna save money. Good luck, and let us see the finished product.

I warned him Kris. I friggin warned him. But there again I remember others having this same conversation with me a little while back. Some times we just need to learn the hard way.

[kcstott]

That is some beautiful machining. I bet you have several hours and then some, just in the lower die. Do you use a press to bend? I have brake that would make quick work in bending the flats with that jig of yours.

great job.

I use the HArbor freight 12 ton press. Works great and has yet to foul up a flat.

The lower die took two full days to square up and hog out. The upper plug is the hard part as you need the proper clearances for the mag stabilizer dimples.
It was cut, fit, cut, fit, cut, fit.......... I wonder if I should tell him he's going to need a folded flat to work out the clearances on the plug??? Oh well he'll figure it out.

[fabguy]

I use the HArbor freight 12 ton press. Works great and has yet to foul up a flat.

The lower die took two full days to square up and hog out. The upper plug is the hard part as you need the proper clearances for the mag stabilizer dimples.
It was cut, fit, cut, fit, cut, fit.......... I wonder if I should tell him he's going to need a folded flat to work out the clearances on the plug??? Oh well he'll figure it out.

Oh cool, mine is a 55 ton press brake I use for bending upto 3/8" x 18" wide flats into angles. Alot of overkill but good if it was a big party once its set up. If you ever need to use use it, let me know.

Looking at your fixture you must have about 12 - 16 hrs into it. Probably. Alot more considering how precise the mag stabilizer dimples need to be.

Want to build an AK from an 80% soon, a member told me about the 1919 & mg42 builds, also want to try one of those each soon.

We'll see

[yari]

Get your m53/mg42 parts soon! Drying up fast.

[hawkeye]

I use the HArbor freight 12 ton press. Works great and has yet to foul up a flat.

The lower die took two full days to square up and hog out. The upper plug is the hard part as you need the proper clearances for the mag stabilizer dimples.
It was cut, fit, cut, fit, cut, fit.......... I wonder if I should tell him he's going to need a folded flat to work out the clearances on the plug??? Oh well he'll figure it out.

Luckily I have a bended flat and a 12 ton press from HF!

[hawkeye]

So I might have found some 4140 which might be enough. Any word on those final dimensions?

[kcstott]

So I might have found some 4140 which might be enough. Any word on those final dimensions?

Soory about that I got bussy and forgot all about it.

Any way so the base is 12"X 3"X 1.75"
The slot is .875" deep the step from the top down is .375" deep This allow the use of a .5" thick clamp on the pusher that will locate before the bend starts.

Now the dimensions for the base are 1.255" at the bottom and 1.3375" at the top

The plug is 1.258" and the clamp plate is 1.250" so there is a bit of clearance on the the clamp but as you can see there is only .0008" clearance on the plug.
.03937" X 2 = .07874" +1.258 = 1.3367" Now Curtis's flats run a touch thiner like .001"- which is fine it's sheet metal, that's normal. And as the sheet bends around the plug it's going to stretch but only in the area that is affected by the radius. I also put about a .020" radius on the plug as I didn't want a dead sharp corner but I also didn't want a huge radius either.



The top of the base has a .125" radius cut on the top to help roll the material into the die.

Also the plug was made from 3/8" X 3 A36 welded together like an I beam.
This was then machined to square everything up and make the top and bottom parallel with each other.
I used 3/8" cap screws to bolt down the clamp plate but the AK builder jig uses 5/16" I also drilled clearance hole in the base to clear the head of the bolts. Then I tapped those holes 3/4" 10 and used large cap screws to separate the two pieces after a the bend is made.

Thats about it. the clearance on the plug was just try it and fit it. until it was right. I still need to clear it out a little more.

Now the critical thing is you need to get the slots machined one center of each other as close as you can to prevent tolerance stacking. I shot for within .001" and was able to hit it. The other thing is you don't want to much clearance on the push to the die base. .001" is more then enough as you can see I kept mine at .0008" a little on the tight side. Things wear and as long as I keep this thing oiled it will last longer then me and only grow .001" at the most.


I guess I should draw up a set of prints and sell them for like $5 a set. For everything though. Plinker jig, flat jig, and trigger guard jig, and front trunnion support jig.
I guess I found my new project.