[bill south]

Hey Guys;
I have some AR-15 zero percent forgings that I would like to have the mag well cut out. I have a small CNC that I can do all the machining but the mag well would be very difficult. I have prints and can even provide g-code from bobcad if it would help. Most important is that the work will not be illegal since it has nothing to do with the fire control group according to the BATF. So, it's just modification to a paperweight.
I have several of these to do (Christmas pres ants last year from my bro), and they will all be for my personal use and I may do one for my BRO.
Any idea what I can expect to pay? Is it even practical??? I don't know anything about EDM pricing but I've seen a couple of forgings which were edm machined and they were beautiful.
Thanks and any information or advice will be appreciated.
Bill

[bill south]

Is there a better way to cut the magwell other than EDM? I don't seem to be getting too much help with this question.
Doesn't anyone have an edm machine sitting idle. Again, forgive me guys, I don't know much abaout EDM.

[skullworks]

Bill;

All the big boys use a monster broaching machine to finish the mag well.

Its quick, easy and almost idiot proof and the size will remain consistent as the broach wears so they only need to gage one about every 50 units.

That said for custom shapes Wire EDM is the easy way - but its going to cost - as in just the wire cut will cost you more than the out the door cost of a name brand receiver from your local gun shop.

You CAN completely machine the mag well yourself. Its a pain but it is doable. There are 2 options.

1] Is standard drilling and milling complete with some hand filing fitting.

2] Is based on the above but adds a step - You will make a guide block that will fit in the mag well as machined and has a corner step milled in it on diagonal corners to act as a guide for a keyway broach. You have to broach each corner twice, once for each side of the 90 degree corner.

I was a Type 07 for 12 years... I made many AR's - its not brain surgery.

[imprez55]

I second what skullworks says:

You CAN completely machine the mag well yourself. Its a pain but it is doable. There are 2 options.

1] Is standard drilling and milling complete with some hand filing fitting.

2] Is based on the above but adds a step - You will make a guide block that will fit in the mag well as machined and has a corner step milled in it on diagonal corners to act as a guide for a keyway broach. You have to broach each corner twice, once for each side of the 90 degree corner.

The third option that has crossed my mind recently is the DIY sinker EDMs. Saying you have more than one forging makes this an even more viable option as it would be the initial investment that would be the biggest cost (around $300 if I remember correctly).

In the EMD section there are plans to basically retrofit a benchtop cnc machine temporarily. I have not tried it and do not know how well it will work out but through links and such there are people using graphite electrodes into files with minimal wear. I would imagine that would be comparable to going through the inches of 7075 (or 6061, whichever you prefer). When I finally get around to making an ar-15 lower I will try to scrape some money together to try the sinker EDM method (I try to do it on the mainspring housing and magwell for a 1911 as well)

Any input as to using the sinker EDM method guys?

[Joezx10r]

http://cncguns.com/projects/ar15lower.html U can read how this guy done it in two setups from top and then from bottom and finished out the radius with a file.

[bill south]

Thanks Guys;
I have completed a couple of receivers by using the mill/drill/file method and it's doable but quit a PITA. I kind of like the idea of a sinker EDM to play with. I found a schematic on the web and have put it on my list of things to do. It's just after the CNC router I'm just finishing, the 65 mustang that is completely dissassembled and just needs "putting back together" and the 300 whisper that I want to build.
Seriously, I really do appreciate the information and was expecting the cost to be too high for my small projects. But, lotz of food for thought.
Everyone have a great day.
Bill

[sodickappsguy]

the last two shops that i helped setup for cutting out the ar-15 mags took around 20-25 minutes per part. see what a local shop will charge per hour and see if they will work out a deal for some idle machine time.

[pico766]

so could anybody shoot out a few Wire EDM machines for douing this.. for a small shop douing parts no bigger than 12inch by 12inch (AR15/AR10 mostly and other custom project) and maybe rigging 2 or 4 receiver at a time ,,

Brand, model?
any type of help would be great


thx

max

[skullworks]

An AR magwell is dirt simple for any wire machine in the respect that it is a simple 2D cut path - the area where it will have a minor issue is when climbing or decending the 2 side walls as the length of contact at the front is much shorter than the area by the trigger guard. Even this is a gradule change so the control should have no issues.

Any CNC wire machine should do the trick. None are in-expensive, though some recent import startups might be "cheap".

[jreillycnc1]

Are looking to buy an EDM to do this or send it out to be done? A used machine might be the best option if your looking for low cost.

[pico766]

I was looking some used ones they wher all going for about 15k $. So yes i was hoping to purchase one,, would prefer a more user frendly model,,, double feed would be great also,,

[bestrada11]

HELLO FRIEND I WORK IN AN EDM HOUSE WELL ITS A EDM SWISS LATHE HOUSE WHICH BASICALLY MEANS ALL I DO ALL DAY FOR 11 HOURS A DAY IS EDM AND SWISS LATHE WORK.. I HAVE 6 EDM MACHINES AND 4 SWISS LATHES. YOUR BEST BET IS TO WIRE CUT THESE AND IF YOU ARE GOING TO DO SO DO THEM IN QTY THAT WAY YOUR SETUP COST GOES DOWN. INVEST IN A PRODUCTION JIG WHICH WILL ALOW FASTER PARTS CHANGES AND YOU CAN PROBLY GET YOUR PRICING DOWN TO LIKE 65 A PIECE IF YOU DID SAY 100 TO 150 OF THEM AND YOU WOULD HAVE ACCURACY TO .00004 IF YOU NEEDED ONE DONE BY ITSELF COUNT ON AT LEAST A 200 DOLLER ENDEVOUR AT LEAST!!!!!!!

[Sho409s]

I've run a Mitsubishi DWC-90, thing is just a workhorse day in day out. You have to replace some stuff as wear items, but they get a lot of hours before a table drive motor pukes or something odd like that. Parts are not cheap and take forever to show up but that machine might run average 10hrs/5-6days a week for half year with nothing but wire, filters, and carbides, and its very far from new early 90s machine I think. I've seen them go for low as $5K but no idea what running condition they were in.

[bestrada11]

well just go the tried and true old school way broaching..... I mean there are only so many ways to cut metal. you may try a waterjet but don't count on that working broaching works but you gotta have a broaching machine plus a high doller broach. you could drill drill drill drill drill drill a little mill and a lot of file, or you could drill one hole thread some wire and 20 minutes later have a cavity cut that is accurate to 40 millionths so idk to me the answer is super obvious. I don't know how much more help with this question you could possibly get.. maybe an alien could come down from outer space and cut the hole with some kind of super duper accurate laser beam!!!!!!!

[malcmpatel8]

I'm running alibrecam standard and want