(yeah, i know that "'jj's brit' in .284" caliber" is redundant, but, i just like the "sound" of it. mea culpa.)
post script. and, something that the supply of which, doesn't dry up by government mandate, machination, or decree. end post script.
i've been "truing up", as best i can, some of the holes in the steel cladding and wood plug, by the judicious use of a couple of round files. it seems to have gone pretty well. by doing so, i've got a pretty good fit between the lower and upper receiver, after truing the forward and rear assembly pin holes.
caption: the above shows a couple of 1/4" x 20 pitch socket head cap screws where the disassembly pins go in a normal ar-15 receiver. the cap screws are a little long, but this was done purposefully, as i wanted the un-threaded shank to go through the lower receiver, so as to not damage the hole in the upper receiver lug.
the excess length of the screws will be hacksawed off, and filed down flush (more or less) with the nut, though i may use the little self locking gizmo's with the plastic inserts in the ends of them instead of what is shown. we'll see.
i tried to find some socket head screws of an appropriate size to use for the trigger and hammer pin holes, but i could not find any 5/32" screws/bolts at the local shops. i was at a bit of a quandary on this, and shouldn't have been, as it turned out.
here's the "mental process" i went through, before a solution suggested itself to me.--
not finding any 5/32's socket head cap screws, i looked to the metric version. close, but no cigar. then i looked to machine screws, and the like. the trouble with machine screws is that they are threaded all the way to the top. for the trigger and hammer pins, i wanted un-threaded shanks, so that the threaded screws/bolts did not eat the interior of the holes in the trigger in hammer, ... , especially, the hammer.
i did not want these parts to wear, especially the hammer, ... , and, there is the fact that the damned things are pricey.
next, i walked by the tool and die section at ace, and saw some thread taps. and, a threading gizmo. (oh, alright, a threading die. you happy?) walked right by it. went about ten feet, and said to myself, ... , wait a second. i've already got the mild steel rod, at .154", which is right at 5/32's of an inch, give or take a thousandth.
eureka!! i have found it. i will simply take an appropriate threading die, and i will take some of my .154" mild steel rod, and i will thread both ends of that rod right to the surface of the stainless cladding, leaving the shank of the rod undisturbed. i will, in effect, have a standard dimension pin, threaded at both ends.
now, in my defense, i had thought about making pins from my round stock, just a little long, and putting "c" clips on the ends to keep them from drifting ... hardly original, as you see this on ar-15's all the time. but, you got any ideas on how to cut the groove for a "c" clip? me, either.
i went out to the local napa store, ... , "napa" meaning auto parts/welding supply store in my part of the world. i talked to the big old guy that has been behind the counter for about a million years, and inquired after the dimensions of available threading dies. if memory serves me correctly, the no. 8 die is about .136", and the no. 10 die is about .149" or so, and that sounds about right. i've got the rod, at about .152-154", and the threading die which will cut that down just a smidge, but past the bearing surfaces on the stainless cladding.
caption: o.k., now, put on your tom terrific "thinking caps," and your junior woodchuck "visualizer," and think just a little bit.
see the two copper-washed mild steel rods sticking out the sides of the receiver, in the middle, above the trigger wells? o.k., i have been using them as i have fit things, but, hadn't really considered using them long term, as i was sort of hooked on the hardened steel pins normally used in ar-15's. forgive me, but, my mind was sort of wrapped around that. i just figured i would use the normal pins
but, i will just thread the ends of the rods, just a bit, so that the threading stops just flush with the steel cladding. in short, i will use them to hold the cladding fast, to pull the pins straight (they will want to "straighten" out at much as possible against the tension of the fastener), and i will use the un-threaded shanks inside the receiver upon which to mount the trigger and the hammer pin.
they are not gonna come loose, they are not gonna turn, nor are they to commit any of the other sins of the normal ar-15 trigger and hammer pins. i forget which of the loctite colors is glue, the blue or the red, but, whichever one is the epoxy glue, that is the one that goes on my threaded rod. as my older brother used to say about stuff on flatbed trailers, it ain't going anywhere.
now, all of you may think that this is just me, running at the mouth again.
please allow me to dissent. there is a purpose behind this extended discourse on what seems a relatively minor point.
and, that is, there is more than one way to skin a cat, and there are little myriad solutions just before your very eyes, if you will only look at them in the correct "view." i bought the steel rod initially to serve only as what we call "slave pins" in the assembly of the ar-15 trigger, ... , suffice it to say, that holding the damn trigger and hammer assemblies for an ar-15 in one hand, as you run the appropriate pin through the hole in a part with the other hand, as you hold the receiver in your other other hand, ... , leaves you about a hand short in your endeavors in assembling the trigger group. well, the solution is the slave pin, ... , you put it in place, and then push it out of the way with the part that is to become "permanent."
cool.
it never occurred to me that i could make a better pin (for an ar-15) out of all the steel rod i own (at $4.29 a pound for the mild steel rod, it is amazing how much of the stuff you can buy for the $4.00 in your pocket.) well, it did when i walked by the threading dies at ace hardware, just like being smacked in the head w/ a dead salmon.
which got me to thinking.-- (surely, a dangerous thing.)
caption: see the great big ole hole in the steel cladding, just in front of the rear disassembly pin hole. hint: it doesn't have any sort of pin in it.
that's where the safety/selector switch goes in an ar-15 receiver. my little homemade gizmo will not accept a standard factory made safety selector switch, because it is to thick, and because it lacks a hole for the selector switch spring and detent.
it occurs to me, my mind "switched to" "flexible" this morning, that i can make a pretty serviceable one from a short 3/8" bolt. why not?
as the caption to the photo suggests, i have concluded that i can make a workable safety/selector switch (i didn't say elegant, i didn't say highly functional, and for christ's sake i did say "ergonomic," sure as hell) from an appropriate length 3/8" hex head bolt. i said, workable. not beautiful, but, workable.
the safety for an ar-15 semi auto is pretty simply. turned "on safe," it presents its full diameter to a stud protruding from behind the swivel point of the trigger, thereby preventing the stud from moving upwards as pressure is applied to the trigger. well, the trigger cannot move. it cannot release the sear engagement against the hammer. it is "on safe."
by contrast, when the selector is turned 90-degrees in arc, it presents a relief cut (flat) into the shaft of the selector, to the upper side on the stud protruding from behind the swivel point of the trigger. there is enough room cut into this relief, to allow the stud to move upwards against the selector switch flat, while at the same time the projection at the front of the trigger moves down and away from the sear surface in the hammer. the trigger is allowed to move. it releases the sear on the hammer from engagement against the nose of the trigger. the hammer falls. the switch in this mode is "off safe," because everything else functioning as it is supposed to, the weapon will fire.
well, you can imagine the rest.
the bolt is chosen for the length of its unthreade shaft across the trigger/hammer well. just enough to not have any threads. a thin nut is placed on the threaded portion, as discussed with the trigger and hammer pins, above. the nut is set w/ another nut, with just enough tension to allow some movement.
the bolt is left its original diameter, except that a flat, or relief if you will, is filed along a portion, to allow the little stud behind the trigger to move upward, disengaging the trigger nose from the hammer sear.
all goes well, "bang" when appropriate, "no bang" when inappropriate.
a little crude, perhaps. but simple. easily replicated by the home hobbyist. and, not dependent upon an industrial manufacturing process to make, and not dependent upon a spring and a detent, and appropriate little reliefs in the circumference of the shaft of the selector switch, to work.
and, something that the supply of which, doesn't dry up by government mandate, machination, or decree.
let me repeat that very artfully drawn statement, and i will highlight it for you, so that you do not miss it.
and, something that the supply of which, doesn't dry up by government mandate, machination, or decree.
fucking kapish?
john jay @ 01.24.2013
p.p.s. let me tell you something about making stuff.-- i've been thinking for a while how to make a safety/selector switch. from the very first day of this project, it's been bugging me. i did not want to copy the standard one .... to much difficult machining, and it would have required a relief well in the receiver, through the metal cladding and into the wood laminate.
and, imitating the holes for the spring and detent would have been, ... , well, ... , daunting, to say the least.
only this morning, when the light dawned on how to do the trigger and hammer pins, did it also dawn on me that a pretty handy way presented itself on the safety/selector.
now, understand this. it will work. it will not work well or as smoothly as the original part. it just won't, it will be awkward and troublesome to engage the safety. but, the fact that i have made a ballerina who does not dance elegantly, does not detract from the fact that i have made a ballerina that does dance some. laughing.
or, as pamela geller is fond of saying, do not let the perfect be the enemy of the good. or, in this case, do not let the perfect be the enemy of the pretty good, or even the serviceable.
besides, the froggies don't even put safeties on their weapons, or if they do, it is only a recent practice. i wondered at this a bit, when first i learned about it, and considered it. and, then it made perfect sense. rifles, especially infantry rifles, are inherently dangerous when loaded. to the froggy mind, you don't want the rifle dangerous, unload it. if it is loaded, it is therefore meant to go off. period.
stay the hell out of the way, if you don't want to be shot, is the french way of looking at things.
i cannot say in my advanced years that i particularly disagree.
JJ -
Looks like a lot of progress. Don't fret over disconnetor or safety, let your trigger finger be your safety. Check out: http://www.boltdepot.com/catalog.aspx?wt.srch=1&wt.mc_id=1 an/or http://www.theindustrialdepot.com/ for special bolts (suggest pan head hex drive to eliminate exterior warts to skin your knuckles. Also, suggest applying epoxy to coat inside an outside and mounting holes to prevent moisture content changes or the receiver. And might not be a bad idea to know what ATF thinks about the notion of organic based fire arms.
Posted by: Rod | January 25, 2014 at 01:04 PM
rod:
i am not too concerned about the "safety." i will file the flat on the shaft so that it will fire.
i will just tighten it to that position.
am looking for an epoxy spray to do the very sealing that you propose. that's why i think my little receiver would be a very good build on some commercial laminate as used in the gun trades ... that stuff is impregnated w/ epoxy, and you could leave it in the atlantic ocean for a month and i doubt it would do much to it.
speaking of organic products, maybe i should see if i could build one of these things out of old left over mashed potatoes and brussel sprouts? it's a thought.
john
Posted by: john jay | January 25, 2014 at 02:12 PM
p.s. you should catch up on my latest posts.--
i am doing the fitment of the trigger group, and that sort of thing.
a safety, of sorts.
and, the sear engagement is nearly perfect.
don't ask me, i haven't a clue how it happened, given all the little misadventures along the way.
but, my theory the entire way is that very little matters in terms of tolerance and dimension, except for the placement and relationship between the hammer pin and trigger pin holes.
put them the right distance from each other, sear engagement is gonna be o.k., and put them the right distance from the front assembly pin hole, and the hammer hits the firing pin.
more or less. laughing.
jjjay
Posted by: john jay | January 25, 2014 at 02:16 PM