AR Paperweights

8752 Views 6 Replies 4 Participants Last post by TheHouse, Mar 19, 2013

Captain Will

Discussion Starter · Feb 7, 2012

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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1 - 7 of 7 Posts

anthony7325

· #2 · Feb 7, 2012

is it a good time to order an 80% lower?

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TheHouse

· #3 · Mar 19, 2013

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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wreckhog

· #4 · Mar 19, 2013 (Edited by Moderator)

Is this an 80% or a 0% lower thing?

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Captain Will

Discussion Starter · #5 · Mar 19, 2013

@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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