thanks

[4thSBCT]

thanks

[TURBOELKY]

Thats significantly off! I never bothered to measure that, but even on the 1mm flats, I usually have to take a hand file to the front and rear trunnion areas in order for the trunnions to sit properly. If not, you'll see the reciever bulge out near the slot area.

Good findings dude, surprised nobody has looked at that before. I know I took material out on my uf yugo for sure. You must be the only other guy thinking ak-builder flats are made in china though, i've been saying that for years!! Lmao!

[SJgunguy24]

Must be metric gauged steel?

I'm gonna put that up to manufacturing tolerances and material grades with the Yugo stubs. Some metal will strech more then others when forming. That won't explain the .10mm though, that would be normal steel allowences working against you there.

[ott1]

I wouldn't use a caliper to measure thickness of sheet metal. That's the job of the micrometer.

[TURBOELKY]

I'll measure my underfolder where I did not take metal off, tomorow. I'll use my calipers too, so we'll be consistant.....

Oh, on a side note... Did you weld the ejector rail in upside down!?! Lmfao!!!

[Ryan in SD]

Hmm, might be using standard sizes closest to metric, in this case, pretty close to 1/16" thick... roughly = 1.6mm

Same story if you ever pin gauge the "4mm" rivet holes. Its actually 5/32"

[4thSBCT]

I'll measure my underfolder where I did not take metal off, tomorow. I'll use my calipers too, so we'll be consistant.....

Oh, on a side note... Did you weld the ejector rail in upside down!?! Lmfao!!!

No I just set it next to it upside for the pic. I took out the 15/64 drill bit before welding it in place and they moved a little during welding

[wash]

You haven't said it in the thread so I'll ask, did the thinned flange solve the bolt binding issue for you?

I have a couple Yugo M72 builds to finish and a couple builds that will use Romy RPK flats from AK Builder so I'll measure my flats soon.

[4thSBCT]

It should fix the problem , I screwed up the flat before I could finish the build. I know for a fact removing material from the top rail with fix it.

[wash]

Ok, I think I'm going to make a jig for thinning The flanges.

I was thinking of just using files to get my Romy RPK flat to 1 mm so that an un-modified Bulgarian style side folder can fit but if I have to do this often, I'll make a plate I can bolt (or tack weld) a flat on to and square up to the mill table.

[4thSBCT]

Ok, I think I'm going to make a jig for thinning The flanges.

I was thinking of just using files to get my Romy RPK flat to 1 mm so that an un-modified Bulgarian style side folder can fit but if I have to do this often, I'll make a plate I can bolt (or tack weld) a flat on to and square up to the mill table.

I have no experience with Ak builder romanian RPK flats so I'm not sure if they are the correct dimensions or not. What exactly are you building? It sounds like your going for a Khyber pass build. I'm trying to picture how the plate you are talking about works...

[wash]

A plate perhaps in two pieces, with a slot milled in it to accept the trunnion bulge and a ledge (parallel to one edge) that the flange will butt up against.

I'll use pieces of round bar stock turned to the width of the milling machine table slots to square the plate to the mill and since the ledge is parallel, the flat will be aligned too.

With maybe 3 step clamps or a similar arrangement, it will be secure for milling.

With the flat tack welded to the jig plate, there won't be any bulky clamps interfering with the milling that needs to be done. If I tack it in the right places, after I am done machining and grind away the welds to remove the flat, all the uglies should be hidden inside the slots in the trunnions.

[4thSBCT]

That sounds like a ton of work. If your trying to get the side folder trunnion to work with the 1.5mm receiver u might consider narrowing the trunnion instead.

[Gowking]

That's what I was just thinking then all you need to be concerned with is supporting the ears that go forward to the front rivet so that they don't deflect under the bit.

-MRA

[4thSBCT]

That's what I was just thinking then all you need to be concerned with is supporting the ears that go forward to the front rivet so that they don't deflect under the bit.

-MRA

If you go slow, there shouldn't be a issue, I've built a 1.5 receiver with a narrowed side folder trunnion and had no issues. Supports would be a good idea though. I'm waiting for someone to make a support so I can just knock out the old rivets instead of drilling them out.