The first time I tackled an 80% lower, I felt pretty excited and a little nervous. I sweat the details, sometimes too much. I wanted to buy a high quality jig and lower(s). I settled on an Easy Jig from 80% Arms. I wanted to buy the best and do it right the first time. What's that saying? Buy once cry once... anyway. The following is a picture tutorial of what I did while milling an 80% Arms Billet Lower using the same manufactures' Easy Jig. Some of my suggestions are only one way I've found to do something. If you have a better way, please feel free to chime in.
The following is a picture of several tools I used during the process. Not pictured are safety glasses, sorry I forgot to get those in the shot. In the bottom left is a headlamp for those of us huddled in our dark garages this winter.
I did did check the level on the vise and the drill press. I made sure that the press was square with the jig. I wanted to give this lower the best chance of turning out great.
The fit and finish on these items are great. I really like the smooth coating on the jig. It won't chew up the surface of your lower and it cleans up easily.
I sprayed my lower and the inside of the jig walls with WD40. I was hoping that this would help repel any scratches and embedded aluminum. We find out in the end if this works.
I only snugged the four main bolts because I didn't want to make installing the top plates difficult. It worked out really well. The top plates were very easy to thread on and off.
The top plates on this jig have tight tolerances. I like it.
The 3/8" drill bit has a locking or limiting collar. I left a small gap at the bottom of the depth gauge when I set the bit depth. This was my attempt to prevent any unwanted dimples after the final router cut. More on this later.
I mounted the depth gauge to the workbench to aid in measuring. The router has a hole around the end mill. One end of the depth gauge tends to dip into that hole making precise measurements a little harder. This step took care of that possible problem. You'll see more of what I'm talking about in a picture to come.
My drill drill press didn't allow enough to room/height to mount the bit then lower it into the jig, so this was how I had to load it each time. It worked out fine.
To prevent the collar from moving I didn't press down hard on the handle once the bit reached the proper depth. I checked the set screw for tightness and kept the bit lubed with WD40. I always stopped cutting once the collar kissed the surface of the jig. Yes, I said kissed
.
After each pass I cleaned out the chips with a vacuum.
This is is a great shop vac attachment that can be purchased at Harbor Freight for about $8. Makes getting inside of the jig much easier.
Once all the holes were drilled I removed the top plate and inspected the holes bored by the press.
This part went well so it was time to move on to the router and vise.
I used vise pads made of delrin. They really helped keep the sides of the jig looking nice.
I wiped off the top surface so that the plates and spacer would mate up nicely.
I had no problem threading on the top plate. Everything snugged up, even and straight.
This router will throw shards of aluminum from here to kingdom come. To prevent that tragedy, I covered my bench and part's bins with a tarp and wrapped it around the vise. This helped greatly when clean up time arrived.
Again, I checked the level just to make myself feel good.
I used a refurbished Dewalt DWP611, which I purchased from CPO for around $100. I really like the adjustable turret and dual led lights.
I wanted to adjust the router so that when the end mill was bottomed out the end mill tensioner was about 1/4" from the jig. This prevented the end mill tensioner from hitting the jig on the last few passes.
I made made sure to tighten the end mill so that it wouldn't free up during a cut. I probably checked the tightness another three or four times during the milling process.
Here is another view. You can see how the depth gauge would tip into the hole on the router base instead of staying square. By leveling it and clamping it to the bench this was prevented. Not a major deal but it made life a little easier, especially since I was doing this project solo.
I wanted to make sure the router speed was optimal so I cross referenced the RPM with the setting number on the dial, by looking it up in the manual. I found that the highest setting of six gave me around 26,000-27,000 RPM as recommended by 80% Arms. This is important to avoid breaking an end mill.
Before starting my cut I insured that the end mill was centered in one of the existing holes.
I adjusted the router until the end mill bottomed out on the top of the lower. This gave me a reference point from which to start on the depth gauge. You can see it's a bit higher than the first tick mark.
Using WD40 I lubed the trigger pocket before each new depth of cut.
After seeing that first shinny patch it's hard to be patient, but go slow. I took my time and I'm glad I did.
I cleaned out the pocket and reapplied WD40 each time.
The shaft lock (yellow button) is hidden at times during the milling process so once I could see it, I took that opportunity to check the tightness.
Grabbing the router down low and moving in a clockwise motion worked best for me.
This is what it looked like right before the final pass. As I mentioned earlier I wanted to avoid any dimples caused by the initial drilling. That's why I left that small gap below the drill bit and the depth gauge. After the final pass they were gone, leaving nothing to be studied by future civilizations. Oh well.
Nice and smooth surface in the bottom of the pocket.
I wanted to just stop and stare, but then I was reminded that there was more to do.
At this this point I decided to leave the rear shelf as is. It will function perfectly and possibly that cross member adds to the strength of an already stout lower.
After wiping it down again, I mounted the plate which would guide the 19/64" drill bit. The beginnings of a trigger hole.
The drill press is very handy on this step to insure a nicely placed hole in the bottom of the pocket.
After drilling the hole I mounted the trigger hole plate and took two shallow passes creating a perfect trigger hole. The process on this jig couldn't be easier.
Overview of the mounted trigger plate.
Again, I wanted to just stop and stare. Beautiful sight.
Almost to the end. I used a 5/32" drill bit to drill out the trigger pin holes. I lubed them with WD40 and only drilled one side at a time. Once finished with one side I flipped it over and repeated the process. I didn't ream these holes with the press as I wanted to make sure they were nice and tight.
The final process is to drill the safety selector hole. I sprayed with WD40 and only drilled one side at a time. I had to place the router plate under my jig to keep it level. It wanted to wobble due to the holes in the drill press platform.
At this this point I was grasping for the allen wrench like a shaky smoker that need a cigarette break. The moment had arrived to set her free.
The lower was a little crusty but I was hedging my bets that the coating of WD40 had protected it from scratches and embedded aluminum.
Quick and gentle wipe down.
Then it was off to my bride's work shop (the kitchen sink). For those of you concerned about a domestic incident just know that she is out of town visiting family.
A little soap, water, and a toothbrush did the trick.
This is after I dried it off.
So, I decided that maybe I could do something about those shinny sections that you can see once it's assembled. Not the trigger pocket, as it's too big but the small sections like the safety holes, trigger pin holes, and the trigger hole.
You be the judge as to whether it helped much or not.
In conclusion, I must say that I was pretty happy with the products. 80% Arms has spent some time and thought this through. The Easy Jig is a wonderful tool. It's made well and should last for a long time, if cared for.
The 80% Arms lower is finished out as nicely as any I've seen. The design is nice and edgy. The finish is seamless. I would buy one again.
I only have one gripe and I've contacted 80% concerning the problem. It seems like the safety hole was drilled too far to the rear of the receiver. This made it so that the detent hole is forward inside of the hole causing the safety lever to rest in the wrong spot. Below is a picture of what it looks like on safe. I'm sure they will help me figure it out. I've always received fast and professional communication from them in the past. I'll keep you posted on what I hear and what they do about it.
Thanks for taking the time to look over this picture tutorial and review. If you have ideas that may help others and myself, please chime in.
Here is a pic of the completed rifle. There is quite a bit of slop between the upper and lower. The upper receiver is a VLTOR, which as many of you know is normally very snug due to its tight tolerances. I haven't tried it on a mil spec upper. I'd probably be really wobbly. After getting the safety issue squared away, I'm pretty satisfied.
The following is a picture of several tools I used during the process. Not pictured are safety glasses, sorry I forgot to get those in the shot. In the bottom left is a headlamp for those of us huddled in our dark garages this winter.
I did did check the level on the vise and the drill press. I made sure that the press was square with the jig. I wanted to give this lower the best chance of turning out great.
The fit and finish on these items are great. I really like the smooth coating on the jig. It won't chew up the surface of your lower and it cleans up easily.
I sprayed my lower and the inside of the jig walls with WD40. I was hoping that this would help repel any scratches and embedded aluminum. We find out in the end if this works.
I only snugged the four main bolts because I didn't want to make installing the top plates difficult. It worked out really well. The top plates were very easy to thread on and off.
The top plates on this jig have tight tolerances. I like it.
The 3/8" drill bit has a locking or limiting collar. I left a small gap at the bottom of the depth gauge when I set the bit depth. This was my attempt to prevent any unwanted dimples after the final router cut. More on this later.
I mounted the depth gauge to the workbench to aid in measuring. The router has a hole around the end mill. One end of the depth gauge tends to dip into that hole making precise measurements a little harder. This step took care of that possible problem. You'll see more of what I'm talking about in a picture to come.
My drill drill press didn't allow enough to room/height to mount the bit then lower it into the jig, so this was how I had to load it each time. It worked out fine.
To prevent the collar from moving I didn't press down hard on the handle once the bit reached the proper depth. I checked the set screw for tightness and kept the bit lubed with WD40. I always stopped cutting once the collar kissed the surface of the jig. Yes, I said kissed
.
After each pass I cleaned out the chips with a vacuum.
This is is a great shop vac attachment that can be purchased at Harbor Freight for about $8. Makes getting inside of the jig much easier.
Once all the holes were drilled I removed the top plate and inspected the holes bored by the press.
This part went well so it was time to move on to the router and vise.
I used vise pads made of delrin. They really helped keep the sides of the jig looking nice.
I wiped off the top surface so that the plates and spacer would mate up nicely.
I had no problem threading on the top plate. Everything snugged up, even and straight.
This router will throw shards of aluminum from here to kingdom come. To prevent that tragedy, I covered my bench and part's bins with a tarp and wrapped it around the vise. This helped greatly when clean up time arrived.
Again, I checked the level just to make myself feel good.
I used a refurbished Dewalt DWP611, which I purchased from CPO for around $100. I really like the adjustable turret and dual led lights.
I wanted to adjust the router so that when the end mill was bottomed out the end mill tensioner was about 1/4" from the jig. This prevented the end mill tensioner from hitting the jig on the last few passes.
I made made sure to tighten the end mill so that it wouldn't free up during a cut. I probably checked the tightness another three or four times during the milling process.
Here is another view. You can see how the depth gauge would tip into the hole on the router base instead of staying square. By leveling it and clamping it to the bench this was prevented. Not a major deal but it made life a little easier, especially since I was doing this project solo.
I wanted to make sure the router speed was optimal so I cross referenced the RPM with the setting number on the dial, by looking it up in the manual. I found that the highest setting of six gave me around 26,000-27,000 RPM as recommended by 80% Arms. This is important to avoid breaking an end mill.
Before starting my cut I insured that the end mill was centered in one of the existing holes.
I adjusted the router until the end mill bottomed out on the top of the lower. This gave me a reference point from which to start on the depth gauge. You can see it's a bit higher than the first tick mark.
Using WD40 I lubed the trigger pocket before each new depth of cut.
After seeing that first shinny patch it's hard to be patient, but go slow. I took my time and I'm glad I did.
I cleaned out the pocket and reapplied WD40 each time.
The shaft lock (yellow button) is hidden at times during the milling process so once I could see it, I took that opportunity to check the tightness.
Grabbing the router down low and moving in a clockwise motion worked best for me.
This is what it looked like right before the final pass. As I mentioned earlier I wanted to avoid any dimples caused by the initial drilling. That's why I left that small gap below the drill bit and the depth gauge. After the final pass they were gone, leaving nothing to be studied by future civilizations. Oh well.
Nice and smooth surface in the bottom of the pocket.
I wanted to just stop and stare, but then I was reminded that there was more to do.
At this this point I decided to leave the rear shelf as is. It will function perfectly and possibly that cross member adds to the strength of an already stout lower.
After wiping it down again, I mounted the plate which would guide the 19/64" drill bit. The beginnings of a trigger hole.
The drill press is very handy on this step to insure a nicely placed hole in the bottom of the pocket.
After drilling the hole I mounted the trigger hole plate and took two shallow passes creating a perfect trigger hole. The process on this jig couldn't be easier.
Overview of the mounted trigger plate.
Again, I wanted to just stop and stare. Beautiful sight.
Almost to the end. I used a 5/32" drill bit to drill out the trigger pin holes. I lubed them with WD40 and only drilled one side at a time. Once finished with one side I flipped it over and repeated the process. I didn't ream these holes with the press as I wanted to make sure they were nice and tight.
The final process is to drill the safety selector hole. I sprayed with WD40 and only drilled one side at a time. I had to place the router plate under my jig to keep it level. It wanted to wobble due to the holes in the drill press platform.
At this this point I was grasping for the allen wrench like a shaky smoker that need a cigarette break. The moment had arrived to set her free.
The lower was a little crusty but I was hedging my bets that the coating of WD40 had protected it from scratches and embedded aluminum.
Quick and gentle wipe down.
Then it was off to my bride's work shop (the kitchen sink). For those of you concerned about a domestic incident just know that she is out of town visiting family.
A little soap, water, and a toothbrush did the trick.
This is after I dried it off.
So, I decided that maybe I could do something about those shinny sections that you can see once it's assembled. Not the trigger pocket, as it's too big but the small sections like the safety holes, trigger pin holes, and the trigger hole.
You be the judge as to whether it helped much or not.
In conclusion, I must say that I was pretty happy with the products. 80% Arms has spent some time and thought this through. The Easy Jig is a wonderful tool. It's made well and should last for a long time, if cared for.
The 80% Arms lower is finished out as nicely as any I've seen. The design is nice and edgy. The finish is seamless. I would buy one again.
I only have one gripe and I've contacted 80% concerning the problem. It seems like the safety hole was drilled too far to the rear of the receiver. This made it so that the detent hole is forward inside of the hole causing the safety lever to rest in the wrong spot. Below is a picture of what it looks like on safe. I'm sure they will help me figure it out. I've always received fast and professional communication from them in the past. I'll keep you posted on what I hear and what they do about it.
Thanks for taking the time to look over this picture tutorial and review. If you have ideas that may help others and myself, please chime in.
Here is a pic of the completed rifle. There is quite a bit of slop between the upper and lower. The upper receiver is a VLTOR, which as many of you know is normally very snug due to its tight tolerances. I haven't tried it on a mil spec upper. I'd probably be really wobbly. After getting the safety issue squared away, I'm pretty satisfied.
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