yes, yes, the eagle has landed. the moment of truth has come, and it is revealed that the plywood gun should function, though it is yet to be determined whether it will function well.
we'll see.
but, tremendous progress this day. i have roughed out the hole in the bottom of the receiver for the trigger, and have borrowed a trigger and hammer, and fit both of them to my .154-.156" pins that i bought from the welding supply house. in one of those rare things, i cut the trigger well exactly, and i mean exactly the right width, and the trigger and hammer snug right down into it, moving freely, without any side to side movement, at all. i mean, none.
caption: there's the trigger, poking out the bottom of the receiver, my left middle finger upon it. and, at the top of the receiver is the hammer, held in place by my indexing finger. the three little holes above my ring finger are for the pins to hold the pistol/rifle grip in place, when i epoxy it to the lower receiver. other little pins are for small cap screws that i will probably use during the final epoxying of the stainless steel clads, if i do epoxy them in place.
to do that, i have to figure out how to hold them exactly in place.
yes, i have built this whole mess exactly backwards, and that should have been the first thing to get squared away. i tried, but i didn't get the epoxy job done correctly.
one of the things i was worried about was whether the holes were drilled to the right distance, and whether they would be square enough to give good sear engagement, ... , to be usable, the rifle will have to go bang when you want it, and will have to not go bang when you want that. to have that, the sear engagement has to be right.
it appears that it is going to be just fine.
caption: it is hard for you to tell from this picture, but i am applying pressure to the back of the hammer, considerable pressure, and it is being held from going up & forward because the nose of the trigger has engaged the sear. when the trigger was "pulled," the nose of the trigger was pulled down out of engaging the sear, and it was able to come up & forward, as designed.
over the trigger well you can see the pin holding the trigger in place.
at 2.30 from the end of my thumb, you can see the pin holding the hammer in place, and the end of the pin is sitting flush with the side of the receiver.
one of my great concerns after the fiasco of drilling holes through the cladding with a drill press, and having the cladding move away from the epoxy supposed to be holding it tight, was the fact that the drill bit on the drill press i was using just "walked all over the place" when it hit the inside of the stainless steel on the opposite side of the receiver from where the hole drilling was begun. i hope you followed that, it was a difficult sentence. but, the simple fact of the matter was my holes where off plumb, and not square, and i was tremendously worried that i would not get good sear engagement if the hammer and trigger pin holes were too far off.
well, use will tell if all of this becomes an issue with prolonged use of the lower.
but, right now, it looks as if things are going to work out so that the gun will function out of the blocks. the baby will take its first breaths, and scream, and begin maturing. now, it becomes an issue of longevity.
but, i have sear engagement. and, it appears true and square, and of full contact. time will tell. but, i am a happy camper this morning.
caption: o.k., for those of you who do not know what you are looking at.-- this is a picture of the lower magazine, taken from the front and from above, looking down into the very innards of the firing mechanism, and the relation between the nose of the trigger, and the sear notch on the hammer.
look to the side of the picture, and beneath my hand you will see a long pin, which is the axis of the arc described by the hammer face when it strikes the firing pin. (think of it as an axel.) move along that axis into the interior of the receiver, and you will see a thickened hub, which has a slot milled into, and a spring in that slot, which engages a groove cut into the pin that locates the hammer in its location, in the center of the trigger well.
below that hub, you will see a rectangular & shiny flat surface of metal, which is the face of the trigger. at the top of that shiny flat surface, and overlapping it precisely in its center (yay!!!, just fucking yay!!!) is the sear notch of the hammer.
this picture is a bit deceiving, as the sear is not that engaged, because the hammer face is restricted from rising a bit, as i haven't relieved the trigger well enough to let the hammer go fully forward, and raise the nose completely into the notch.
tomorrow.
but, i have a good relationship between hammer and trigger, because the trigger pin hole and the hammer pin hole, while not in perfect alignment, are in good enough alignment. pretty good, for the hammer and trigger pin holes, given the nature of the way the sears have lined up.
as far as the safety goes, i will have one, but there is room for lots, and i mean, way lots, of improvement. i've got to figure out something that will allow me to index it into the correct position, and keep it there. and, to be able to move it back and forth between "on safe" and "off safe."
but, i'lll worry about that in a little bit. right now, i am just very happy with the way the things have gone with the trigger group. update, 01.26.2013. one of the realities of starting something like this, (at least for me), is that you cannot think of every damned little thing at once. in other words, you really don't solve your problems until you come to them. (so, don't let that stop you from getting in over your head, ... , that's part of the fun.) i was in the tub the other day, soaking my poor old tired legs, thinking of all the difficulty of machining grooves around shafts and the like (which i cannot do, not being a machinist). and, then, i got to thinking of putting a detent of some sort on the outside of the receiver cladding, just screwing it in place. (that's the way the brits built revolvers for years, ... , why put something on the inside when you can hang it on the outside?) and, then it hit. the spring/detent housing for the colt 1911 pistol, and other related guns. why not just get a spring/detent/housing unit for a 1911, and mount it smack right up against a 3/8" socket head cap screw .... which has got a perfectly suitable ribbed surface to make stay put with a spring loaded detent? it might work. i am going to look into it. and, hells bells, i can drill and tap a couple little holes, and screw the damned thing on, if that's the way it works. end update.
the whole arrangement between the hammer and the magazine/magazine well is very crowded, very tight, indeed. it would appear to me at this juncture that i am going to have to make some relief cuts for the trigger spring, and probably do some minor surgery to the magpul ar-10 magazine to give the hammer enough room to swing freely, and contact the firing pin in the bolt carrier group with sufficient force to insure cartridge ignition. gotta have that, to have it go "bang" instead of "phizz." "phizz," we don't want.
caption: when i say things are tight, i mean that they are tight. here is a good view of the front of the hammer, and as of yet there is insufficient room for the hammer spring. that will have to be addressed. and, the front of the hammer strut has to share space with the back rib on the magpul magazine, ... , which feature appearing to me absolutely useless, is going to be sacrificed for the good of hammer function.
i've already decided on that. in my mind, it's a done deal.
and, are things tight in there. if you look towards the rear of the receiver, you'll see two little metal "bands" with a small section of shaft running through them. well, that's the hub, or the center upon which the trigger rocks, and that little shaft is a section of the .154"-.156" pin that holds it is place, that the whole things swings on. oh, yes, parts are close.
the hammer spring? i am going to have to give that some thought.
what remains?
well, i have to figure out how the hammer & hammer spring get sufficient room to operate, and i know it is going to be at the expense of the magpul magazine. it is going to have some material removed from it, and, the good lord willing and the creek don't rise, its function will not be grossly impaired.
we'll see.
and, i have to figure out, 1.)whether i am going to epoxy the cladding into place, and i am not sure, because the bolts and fasteners are holding it pretty steadily just where it belong. the receiver does not exhibit any movement between the cladding and the wood plug when the upper is in place, and maybe i can get away without doing the whole epoxy thing all over again. (it would be just, ... , very disappointing, to have that go wrong, and compromise all the progress i've made.) and, 2.)if i do decide that i need/have to epoxy the cladding to the wood plug, i've got to figure out how to do that, and hold everything just in the right places, and not have pin holes "wander off," and the like.
i'll keep you posted.
john jay @ 01.24.2013
update. update. update, 01.25.2013. (yeah, i am pumped.)
up bright and early, to install the safety. it's in, after relieving the bottom of the trigger well enough for the "hind foot" of the trigger to slide in underneath the safety.
caption: it does look a little bit like frankenstein's monster, with all the shafts and lugs sticking out the side of things. but, that big ole 3/8" bolt is over the trigger, just barely out of contact with the shaft of the safety.
wait until you see the sear engagement below, and you will understand why this rifle is never going to go off when "on safe."
in the previous photograph you are looking down into the trigger well from above the receiver. you can see the top of the trigger, but you cannot see how well the sear is engaged. it's pretty startling in real life, but i have got absolutely full engagement of the nose of the trigger with the sear notch in the hammer. there are wear marks on the face of the trigger from use in its previous installation. (the parts have to go back to that lower, because it sits at a friend's house, in "parts." very gracious of him, under the circumstances, i would say.)
click the picture ... put the cursor on the enlarged picture, then put the little "magnifying glass" right on the sear, and click it. then look. and, you'll see the hardened surface of the trigger nose, and the overlap on the sear notch. perfect, at least right now.
caption: looking down into the magazine well from the bottom of the receiver. look to the top of the magazine well, and right beginning of the trigger well you will see the face of the trigger, which is a polished hardened bit of steel. (that's why its shiny!!). overlapping the front of that rectangular trigger face, is the sear notch of the hammer.
it's pretty much just right. i don't know how it happened, quite frankly, given all the mishaps involved in drilling the holes into the receiver clads and plug, but, it all came out. maybe all the errors were in synch, ... , i don't know.
when it all goes together, the trigger should function perfectly. now, whether i can get a magazine with cartridges up past the hammer, i don't know just yet.
something has got to give. end update. end update.
Well...
That was a bit of a read to slog through this morning while the wife/kids are waking up and being...grumpy girls.
And they wonder why I wake up at 5 for some peace and quiet.
Anyhow, as I stated before, I'm getting excited to see the video results.
Posted by: rightwingterrorist | January 25, 2014 at 05:24 AM
right wing:
a ways away yet.
gotta get a lower receiver parts kit, because the trigger and hammer shown are from a friend's ar-15 that he loaned me, and the stuff has to get re-installed in his.
i have to check to make sure i have enough to eat on for the rest of the month, after the utilities are paid.
and, as noted always, i have to get an upper that will accept the ar-10 magazine well. or, i could just find the magazine back to ar-15, and fire it in the "jj's brit" upper in "jj's brit."
but, i don't want to do that. i want to make my own dedicated upper for this lower, using steel seamless tubing, and along the lines i have discussed previously.
you are about 6 months out,i would imagine. check this post for an update.
the sear has gorgeous fitment, and the trigger well is relieved under the "backie stickie outtie" on the trigger so that the safety goes in, and functions perfectly.
with the safety "on safe" its gonna take spontaneous combustion of the power to set a round off in that thing.
absolutely gorgeous sear engagement, is what i am saying.
john jay
Posted by: john jay | January 25, 2014 at 10:05 AM