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Discussion Starter · #1 ·
Starting this thread to update the folks that have contacted me about making my mill available to them so they could complete AR "paperweights". Rather than answer PM and emails, I will just post progress on this one thread.

Currently I have the hole locations for the three undrilled holes figured as follows:

Reference Zero = pivot pin center (X0,Y0)
Hammer pin hole = X3.604 Y-.375 DIA .156 (5/32)
Trigger pin hole = X4.447 Y-.689 DIA .156 (5/32)
Selector Hole = X5.572 Y-.464 DIA .375 (3/8 )

I have code written for the FCG pocket. I need to test it still. I started with an M16 drawing, to take some missing measurements off of:


Found this drawing and got the rest of whjat I needed off of it, verified on two (LRB) lowers I have:


Hand coded the toolpath from the hybrid set of dimensions:


So, still on the list is that I need to make a jig or set of vise jaws that will hold the paperweight and has a set of holes and a pin to index the pivot pin, which I am using as 0,0. Hope to get to that over the next couple of weeks, time permitting.

First though, I will cut the toolpath in a test block so I can do a dimensional check.

Will update once I have toolpath verified. That's it for now.
 

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I'm completely new here. I don't now why I felt the need to say that but what a relief. I feel like I should out that in my journal or something..... Anyway, I ordered one from a crowdsourcing program called 2nd am arms. I have no idea what the build quality is since they are absolutely new to the market.

I have a drill press and I'm ordering a jig for the project. I'm in eastern Nassau county and wouldn't mind getting to speak to anyone who gave this a shot. I missed my opportunity to purchase one outright but I don't want to wait around anymore.

If you have any input on this sort of build, I'm all ears.
 

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Discussion Starter · #5 ·
@wreckhog: Top pic in your post is an 80%, bottom post is a 0%. Anybody on here with a 0% will need a mill and to perform a number of operations and setups to get it to 80%. At that point you are basically a machinist and can finish it youself. There are detailed instructions here: http://arlower.ray-vin.com/ar15/ On the other hand, if you buy an 80% lower, you need to drill only the three lateral holes (hammer pin, trigger pin, selector) and mortoise out the FCG pocket. The holes are easy enough to measure and drill on a press, but the pocket requires a lot of patience or a special jig, which is expensive. The file above solves that issue by providing a generic instruction set for any CNC machine to cut the pocket.
 
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