A friend of mine has convinced me to build from a flat it seems most on here build from purchased receivers that require no bending. I am very mechanically inclined and feel I can build a gun that works from a flat but this post bothers me:   http://www.ar15.com/forums/topic.html?b=4&f=51&t=78858




please shoot me straight

I am planning on purchasing a flat bending jig from DPH after the holidays.  I figure that if I want to eventually start building from flats, I may as well get the proper tools and resources together.

You can build one from a flat, but don't try it without a bending jig.  Once you have the proper tooling (an appropriate bending jig), it's just a little more work.

Most 100% receivers sell for about $70 or less, and a lot of people feel that considering the price of jigs and the extra work, $70 is worth buying a receiver that's already ready to build upon.

I would like to hear some success stories or horror stories of guns built from flats

I have had both.

I used a "reputable" jig, and it gave good looking flats, but the top rails are a bit off  (to low) in the front. And the jig didn't come up high enough to give the rail a good sharp 90 degree bend.

and one hole tends to be off ont he front trunion, by half a rivet diameter. Don't ask me how.

I have had better luck using the "cut-with-a-dremel-and weld"

my trick, is clamp some 1 1/4 X 1/8" weld steel to the flat, use this as a dremel guide.


you can make perfectly straight cuts, leave tabs, lots of tabs, at about half thickness, and cut through all the way in other spots. "bend by hand" then mark the top rails, using your trunions to find the right fit. mark and cut and bend same as the first two, after you have a box made up, fit and clamp your trunions in place, with rivets in but not smashed yet.

P.S. make the cuts on the "outside" of the receiver.

here is the neat trick. use a wire feed gasless mig.

take small angle aluminium, L stock, small and thick is best. take small peices and clamp it in the creases of the receiver. now weld from the outside, and the aluminum can be easily popped out afterwards,. the weld won't stick to the aluminum. and it won't penetrate the aluminum, so no burn throughs, and perfect insides.

when welding, use medium speed and low power.

make short little tacks, about every inch, cool it, and repeat, you should take at least three passes to fill most of the cuts. build up some extra.

after you have all the cuts filled in and built up, undo everything, and take it to a belt sander/grinder.

make 90 degree angles you can make the receiver nice and sharp.

you will now have a strong, shapely shell.

mine it ugly as heck, I didn't think to do the aluminium trick,  and I didn't build up the cuts enough to make tham all sharp 90s. but it runs perfect, and it a lot stronger than the normal bent flats, the welding hardens the metal, yet leaves other areas soft, so the gun is like a samuria sword...

and I cannot underemfasise a good polishing job of all areas of contact. everything must be smooth and strait in the rails areas. and careful to avoid binding,

recevers can be widened and narrowed after trunion riveting but be careful.

My first build was a Romy built on a Tapco flat. I bent the flat on a jig I made myself. I've put 500+ rounds through the rifle without a problem. The hardest thing for me was heat treating the receiver without warping it. I warped the first one. I clamped the second one to some 1 inch angle iron when I heated it. That worked well. I'm not mechanical genius so I think if I can do this so can anyone with a little bit of skill. Good luck.

has any one else had a warping problem

btt

This talk about warping makes me wonder how they are heating an quenching them. If they are just doing the holes, there should be no problem.

If they are doing the whole receiver, then they should be quenched vertically, not sideways.

John

I just built one useing this guys instructions on bending without a jig.  www.akparts.com/akinfo6.html  I recomend going thru this whole site.  Very interesting info. I hardened the holes and screwed it together.  I even screwed and loc-tied (red) the rails on with 6-32 button head screws.  It works perfectly.  I have not put that many rounds through it at this time, but the several mags I have put through worked perfectly after I cleaned up all of the burrs.  The flat was a TAPCO 12.99 flat.  The next two will be the coldsteel solutions pre-bends.

i wish i was mechanically inclined like that.  I'd just wind up with a paper weight

Quoted: I would like to hear some success stories or horror stories of guns built from flats

I've built about 17 from flats, all good. When I started I used a block of hardwood I cut to the same dimensions as my Century Arms receivers internal measurments. It wasn't very good, the edges weren't perfect 90 degree angles, it took a lot of fitting to get them to go together properly, but I built several that way and all worked.
Now I built my own jig out of steel, I bolt the flat in on the bottum, then just bend the sides over with a brass mallet, then clamp something to samwich it to keep the sides flat while I hammer the top rails over.

The only problem I have is that for some reason I have to grind down the selecter stop on most of my builds to make the mag sit higher, or the bolt will accasionally skip over the round in the mag. My home built receivers look better than some store bought ones. A guy had a picture on here of some POS he bought (from green light arms, IIRC)

The flats cost $12, so give it a try! That's about what a back ground check'll cost ya.

Quoted: This talk about warping makes me wonder how they are heating an quenching them. If they are just doing the holes, there should be no problem. If they are doing the whole receiver, then they should be quenched vertically, not sideways. John

Most builders only heat treat the holes and do so with a MAPP torch. It's VERY possible that my problem with warping resulted from my heating the receiver  longer than necessary. Sometimes you have to screw up to learn. As real estate salesman said the flats are only $12.00 so if you decide to try this buy a couple extra. If the first one works you can build another rifle.

Quoted: I just built one useing this guys instructions on bending without a jig.  www.akparts.com/akinfo6.html  I recomend going thru this whole site.  Very interesting info. I hardened the holes and screwed it together.  I even screwed and loc-tied (red) the rails on with 6-32 button head screws.  It works perfectly.  I have not put that many rounds through it at this time, but the several mags I have put through worked perfectly after I cleaned up all of the burrs.  The flat was a TAPCO 12.99 flat.  The next two will be the coldsteel solutions pre-bends.

Thanks much for the link swordsling.I also have instructions on bending with a simple jig that dosnt use a press,just a block of wood and a hammer.My BIL was supposed to be building me one,I downloaded the instructions from gunco,gave him one of my flats and an ace template,and havent heard from him since thanksgivingHis damn phone is turned off,so I cant call him either.Oh well.

Dude, do you realize your BIL has absconded with your AK, and is shooting the crap outta it?

Quoted: Quoted: I would like to hear some success stories or horror stories of guns built from flats I've built about 17 from flats, all good. When I started I used a block of hardwood I cut to the same dimensions as my Century Arms receivers internal measurments. It wasn't very good, the edges weren't perfect 90 degree angles, it took a lot of fitting to get them to go together properly, but I built several that way and all worked. Now I built my own jig out of steel, I bolt the flat in on the bottum, then just bend the sides over with a brass mallet, then clamp something to samwich it to keep the sides flat while I hammer the top rails over. The only problem I have is that for some reason I have to grind down the selecter stop on most of my builds to make the mag sit higher, or the bolt will accasionally skip over the round in the mag. My home built receivers look better than some store bought ones. A guy had a picture on here of some POS he bought (from green light arms, IIRC) The flats cost $12, so give it a try! That's about what a back ground check'll cost ya.hr

ive been feeling good about bending them but your making me feel even better  thanks sales man

Quoted: Dude, do you realize your BIL has absconded with your AK, and is shooting the crap outta it?

Naw,just gave him the flat,a glue on template and the plans to the jig.I hope to someday hear from him,the wife spoke to her mother tonight and he lives close to her and stops by often,I asked her to mention it,but I wont hold my breath