[kingjamez]

I built a bending jig similar to the one in this video:
http://www.youtube.com/watch?v=3H5EGr0gzdk

He's got his rails welded before he bends which seems like it would be a lot easier. How should one do this? Is there a good way to index the rail that is not the back of the installed trunnion?

-Jim

 

[Loyal11475]

Not unless you use inferior TAPCO receiver flats, which have the holes predrilled in the rails and receiver. Line them up and I would think they would be pretty much where they need to be, but of course I don't use Crapco receiver flats....... If you use Ak-Builder premium flats, I would think you would have to make some kind of jig to set the rails where they need to be then spot weld them in. This would be a generic fitting though. Every trunnion is slightly different though, I like custom fitting mine to each individual trunnion and then welding them in so there is never a question on fit.

 

[AK-Karl]

I would never attempt to weld my rails in before I bent the flat.
That is a good way to cause problems before you start your build.

 

[pupwag]

With the top rail already bent as in the video just set the front trunnion alignment groove on the rail
and use the appropriate size drill blank to set and parallel the lower rail.Used to do it that way with the Pexto brake.Just another way to skin a flat.

 

[Captn C]

With the top rail already bent as in the video just set the front trunnion alignment groove on the rail
and use the appropriate size drill blank to set and parallel the lower rail.Used to do it that way with the Pexto brake.Just another way to skin a flat.

This is what I do do too. I built a bender like that as well.

I set the front trunnion on the rail and use the drill bit to keep the two rail parallel...seems to be working fine right now. I assume you are welding with a MIG too. I welded in some rails from the outside and didn't like working with the "bump" of the spot weld.

 

[rattleAKAK]

Putting the cart before the horse as far as Iam concerned. You give up all adjustability for trunnion fit.

 

[HobbyMachinist]

Putting the cart before the horse as far as Iam concerned. You give up all adjustability for trunnion fit.

I agree. While it's less of a problem with the more forgiving 7.62 rifles, 5.45 is very picky, and If you screw up the rails just a little you'll end up with BOB (bolt over bullet)