Do the pivot pin and takedown springs ever wear out over time (loose their tension, etc...) ??
Also, I installed the hammer but the diagrams didnt make any sense about the orientation of the spring. I did it the way I thought would work (ala AK/RPK) and I got some nice tension... the hammer (when you cock it down) sticks up but its only a triangular shape. It looks to be held by the front part of the trigger assembly and not the disconnector.
The safety only works with the hammer cocked (seems weird, my AK/RPK will do safety regardless of the hammer position).
I've got 90 year old rifles with similar small springs that still work fine. Provided it's a low-stress location that isn't worked 500 times per range outing (like the pivot pins) I wouldn't worry much.
The hammer is supposed to stick up.. A little triangle just like you described. The disconnector only holds the hammer when the trigger is pulled. With the hammer uncocked, safety off pull the trigger. Now cock the hammer down, it will catch at the disconnector. Release the trigger. The hammer will go "thunk" and slide off the disconnector. Now it's cocked on the trigger itself, at the little notch in the hammer near where the pin passes through. Pull again and the hammer will drop. (catch it before it hits if you don't have an upper installed!)
The safety thing is normal too.. Bugged me at first, but think about it.. If there's a round in the chamber, the AR is cocked (or the round is a dud). If there's no round in the chamber, why put it on safe? The only advantage would be that the rifle could be safed before charging, eliminating the split second of live weapon between charging and flicking the safety. Too complicated. The AK can't clear a live round from the chamber without taking the weapon off safe though, so everyone's even