I studied the thing upside-down and left-ways while I was assembling it.

I got it assembled just right on the first try.

I *STILL* do not understand what the surfaces are doing that give the two-stage feel.

Can somebody please explain to me what exactly is the mechanical action that takes place while this trigger set is operating?

http://i227.photobucket.com/albums/dd7/rkba2da/RockRiverArmstwo-stagetrigger.jpg

Is it installed in your lower? If so you should feel a slight creep (take up) on the initial stage followed by a crisp release (break) on the second stage. Hence Stage 2

double tap sorry

Thanks for the reply.

But, I understand THAT much.

Can somebody tell me exactly what surfaces are engaging/disengaging as the trigger moves through its range of motion?

you have the hammer and trigger hooked in your pic.  when installed I dont think they over lap that much.

1st stage the take up is removed from the trigger (not creep that is sear movment).

on the second stage those two hooked surface become unhooked.  If they were that much overlap you would notice creep.

that tower  to the right is the disco. It resets the trigger to keep the gun from going FA when the BC assy moves rearward and pushes down the hammer.

You say "1st stage the take up is removed from the trigger (not creep that is sear movment)"

Hold the phone here.

Those spring-loaded metal parts aren't just floating in outer space during "take up."
What metal surfaces are engaging during "take up?"

The parts that are rubbing in the first stage, are not rubbing in the same way (if at all) during the second stage.

There is a definite mechanical event that occurs when the first stage ends and the second stage begins.

Can somebody please explain it in clear detail?

I just installed 2 sets of these in my lowers and have no idea. I did not get a 2 stage feel. I thought it was just supposed to be a crisper trigger with less travel.

I don't know if this is the answer you are looking for:
While the trigger is pulled back and the hammer is forced down by the bolt, the Disconnect pivots down onto that small spring as the hammer egages it. As you release the trigger the disco pivots back up, still engaging the hammer until such point as the hammer is released from the disconnect and is captured by the trigger's sear.

I guess they need the disconnect to have some travel so as to keep a hold of the hammer until the sear can latch onto it.

what you have pictured is touching during take up.

the hammer is one part.

and I think the trigger is at least 2 major parts.

During stage 1 no movment is happening for the hammer.  the trigger and sear are getting set, ready to trip the hammer in the second stage.

I appreciate y'alls efforts here.

I understand what happens with regard to how the disconnector operates.

What I cannot explain in correct detail is the sequence of events that occur as the trigger moves from its "ready" position, then through the first stage, and then through the second stage.

What I'm looking for is something like this:

At rest, surface X is engaged with surface Y (and possibly also surface Z?).
As the trigger moves through the first stage, surface X slides along surface Y.
At the point where the first stage ends, the engagement load shifts from surface Y, to surface Z.
The release point occurs when surface X disengages from surface Z, allowing the hammer to move forward under spring force.

Something like that please.

The way you have the parts in your pic is the way they are seated before and during trigger pull.  Those 2 surfaces are the ony areas that are in contact.  As you pull the trigger the, its contact area with the hammer moves forward(to the left in the pic) and slides off the surface of the hammer, releasing the hammer.

height=8

Quoted: The way you have the parts in your pic is the way they are seated before and during trigger pull.  Those 2 surfaces are the ony areas that are in contact.  As you pull the trigger the, its contact area with the hammer moves forward(to the left in the pic) and slides off the surface of the hammer, releasing the hammer.

There has to be more to it than just that.

How can there be such a noticeable transition from the first to the second stage if there were not some sort of mechanical trasition occurring when the pull moves from the first stage to the second?

Here's a pic that reveals what my thumb obscures in the pic above.

http://i227.photobucket.com/albums/dd7/rkba2da/rockrivertrigger2.jpg

I'm thinking that during the first stage, there is some engagement between the nose of the trigger and the notch that appears on the hammer at 6 o'clock relative to the hole for the axis pin.

Are you telling me those surfaces play no role in the feel of the "pull?"

Ok here we go
In your picture the hammer is hold by the hock( on the trigger)  pointing to the right
At the first stage ( pressing the trigger)this hock is moving to the left ,this should be a light pull
If the trigger is pulled enough  the hammer slips of the hock ,,BUT before this can happen
the part on the hammer pointing towards the disconector ,is touching the disco
The disco is under spring pressure ,to let the hammer fall you will have to pull the trigger a bit harder ( second stage )this will press the disco back and the hock even more to the left ,and now the hammer can(and will) slip of the hock BANG
In The first stage it is only the trigger spring you feel ,on the second stage it is the trigger spring AND the disco spring you feel

If you look down into the fire control well ,you can see this happen .try it ,but remember to catch the hammer so that it dosnt break the bolt catch  

If you keep the trigger pressed  ( one normally does ) the disco is now in the forward position ready to catch the hammer when the gun cycles ( just like a ordinary AR trigger )letting go of the trigger( if the gun has cycled ,ore you have manualy recockt the hammer ) should let the hammer fall from the disco into the trigger sear( you will hear a click ) now its ready for the next (semi auto) shoot

Excellent response!

When I was looking at it, I thought that might be what was happening. But, I couldn't bring myself to beleive what I was seeing.

Thanks!

Not to rain on anybodies parade, but who cares :D

If you're still needing 'splaining, go check Nationalmatch.us.  I put up a diagram like you asked for.

Quoted: If you're still needing 'splaining, go check Nationalmatch.us.  I put up a diagram like you asked for.

do you have a link ,,i did try but you have to register ,,where is it

height=8

Quoted: height=8 Quoted: If you're still needing 'splaining, go check Nationalmatch.us.  I put up a diagram like you asked for. do you have a link ,,i did try but you have to register ,,where is it http://www.nationalmatch.us/forums/index.php?showtopic=9577&view=findpost&p=80754 Here's my simplified explaination of the 2 stage AR trigger (this is actually a MKII trigger schematic, but functionally it'll work the same...oops, did I say that...never mind...whole 'nother story!); 1) Your primary engagement surfaces are "A". Cocked and at rest, this is where the engagement is. 2) Pull on the trigger and it pivots on "B". Engagement between Hammer hook and Trigger at A slides toward disengagement until the rear hook of trigger hits a stop on the front of the disconnect at "C". Engagement at "A" is still there, but minimal and ready to go. This is the "First Stage". 3) Continuing Pull on the trigger will cause the disconnect to push on the rear hammer hook at "C" and the disconnect pivots on "D" by compressing spring at "E". That "Second Stage you feel is the rear hammer hook hitting the disconnect, then compressing the spring at "E". 4) That little movement of the disconnector is also allowing that last bit of engagement at "A" to go away. When that last bit of engagement is gone, the Hammer is released and "Baby go boom"! 5) After firing, when the trigger is held to the rear, the bolt cycling will recock the hammer and the disconnect hook will catch the hammer at "F". 6) Letting the trigger return forward causes the disconnect to disengage and "hand off" the job of holding back the hammer to "A" once again. When you try it dry (please make sure chamber is empty), you'll hear the click of the "hand off" when you release the trigger. 7) Rinse and repeat. There's more to it than that, but those are the basics. Hope that was what you were looking for! http://img.photobucket.com/albums/v474/BlingRat/AR_2StageTriggerFunctioncopy.jpg

Thanks for the info guys...

I just bought a white oak armament 2-stage from ADCO (it's a tuned RRA unit),
and installed it this evening.  LOVE IT!

I had the same question - wanted to know how exactly it worked.
A quick search led me to this thread...  Thanks!