GunLab

Making the AR-180B bolt hold open button

This post is about making the pivot button for the bolt hold open device for the AR-180B.

With no engineered drawings to work from the first item of business to take care of was making a drawing of the part with all the dimensions. To do this we used micrometers, feeler gauges and an optical comparator.

Using these measurement devices we were able to accurately measure the the complete button. We also used references from parts suppliers to verify correct dimensions for matching components.

http://www.mcmaster.com/#97431a290/=xirvt8

Side-Mount External Retaining Ring (E-Style)

Black-Finish Steel, for 7/32″ Shaft Diameter

For Shaft Diameter	7/32“
Fits Groove
Diameter	0.188″
Width	0.029″
Ring Size
(A)	0.437″
Thickness	0.025″
Additional Specifications	Black-Finish Steel
RoHS	Compliant

Snap rings into the groove from the side of the shaft. Their three prongs make contact with the shaft and provide a wider shoulder than other external retaining rings for a larger retaining surface. They are magnetic.

Black-finish and zinc and yellow chromate-plated steel rings have a minimum Rockwell hardness of C47.

Next came a solid model of the part.

A program was written with master cam to run on the cnc lathe.

This is the video of machining the part on the lathe.

This is an picture of the part as it comes off the lathe when the first op is completed.

A comparison of the original part to the newly machined one.

What has been done so far with still more to be made.

The second op to come

Saturday’s post

Today is a shop day as I am trying to get the pivot buttons completed for the AR-180B and finish the third op on the selector knob. I will post a video later today on time in the shop. I also chatted with Todd at McWilliams company and he was a great help on the Japax wire edm. I hope to have another video on the Japax this weekend as well. Later for now.

Machining the safety shaft for the AR-180B

This is the video of the actual machining of the AR-180B shaft. This is the first op in making this part. From here it will nest go to the mill to have the various flats, slots and holes drilled. Now on to the first op.

With the first op complete the next step is to write and set up for milling the part.

All the safety shafts turned.

Working on the safety shaft for the AR-180B

Sorry for the late post today. When I finally got home last night I went to the shop to work on the shaft for the AR-180B safety and did not finish until late. This is a quick master cam video on the process to do the first op on the shaft.

Here is the picture of where we are now on the project.

I have a video of the machining that I will post later.

Weekend update 5-31-15

Now as much to chat about this weekend. Spent most of Saturday machining the AR-180B selector second op. The second op is now complete and we will be setting up the Sharps for the third op. The material and tooling is in to start on the safety shaft on the lathe then the pivot button for the bolt hold open device.

I added a new isolation valve to the air system.

This will allow us to isolate the air compressor for the air system in the shop. Making it easier for start up and shut down. A new electrical switch is being added as well. This will control the air dryer from inside the shop.

I finished the mods to the shop welder and it is now back together. I still need to finish the water cooling system.

Close up of the lower bar.

The stem wall framing was completed and the concrete poured. I will set up for the slab next weekend.

Forms removed to clean up the wall. This is the sand area.

The larger area is the actual casting area and will be sand filled.

This smaller area will be where the furnaces will set.

Most of Sunday, after the hard work project was completed, was spent on playing with the wire edm.

I learned a great deal but still miles to go.

Japax wire edm

I am going to start a series of posts on the Japax wire edm. I am doing this for a variety of reasons. The first is that it is an easy way for me to show Brett, by the way who is a great guy, at McWilliams sales and service , http://www.mcwilliamsedm.com/index.html, what is going on with my machine and the problems that I am having. The second reason is that there is nothing out on the internet either in video or written walking someone using the Japax wire edm. Initially this will be a little choppy and I apologize for that but it is hard to ask the question if you don’t know what to ask.

My initial goal is the first clean out the machine and get it ready to work, then to hand write a program to allow the table and upper head to move and position properly. Once I have these two steps completed I want to be able to feed the wire and make a small part on the hand written program. Then finally make a solid model, post the model to a cam program and down load it to the machine and make a part.

On Monday I will be calling Todd, there service engineer, over at MCWilliams to discuss the cleaning process for the machine.

On the programing side I am trying to find out what are the specific G and M codes for this machine. How to, on a step by step basis, program the machine. I have read the manual but I am still not sure what screen to be in and how to input the code. Some of the questions I have are as simple as is there a machine home button.

This will be a interesting learning process and one that I hope will provide a new and operational machine for the shop.

Here is the first in the series of video’s on the Japax wire edm.

Here are a couple of pictures of the basic machine. This first one is the control panel.

One of the machine it self.

A close up of the work area.

Sunday afternoon update.

Spent a few hours trying to get the EDM to work, still no luck. However, I was able to write a program by keying in 13,data edit. Once in this mode I could input individual lines of code by typing I/N001/and the code.

But when we typed 8on NC set and input the program by either typing 1 or 0 I would get errorA01. Still stumped.

Op 2 on the AR-180B selector lever

Saturday I spent most of the day finishing up the second op on the selector lever. Here is a run down of that operation.

Starting with the finished op one part.

A special set of aluminum jaws were machined to hold the selector levers.

With the jaws finished and the parts installed this is how it looked prior to machining.

Two sets of vises were used allowing 4 to be done at a time.

This is the video of the parts being machined.

A close up the finished machined part still in the vise.

Start to finish of this operation.

The completed lot.

One more op to go then tumbling and parkerizing.

Making parts for the AR-180B

We were down to see our friend Rick at http://ar180s.com/ a while back and over the last few weeks during conversation he was interested in if we could make a few AR-180B parts. Why not that’s what we do. So while we are waiting for ATFE approval on the VG1-5 and the machines are kind of idle we started a project to make impossible to get fire control parts for the 180B.

The first part we decided to tackle is the safety selector. This part is specific to the 180B as it is longer then the standard safety for either the 180 or the ar-15. The orginal ones were investment cast so making them that way was out of the question. What we did was to redesign it to a two piece part.

A quick look at the master cam video of the first op being performed.

This is the actual video of the part being made.

This is what the parts look like after the first op is completed.

Here is the complete lot done with this op.

Weekend update part 2 the metal casting area.

Nothing says fun around Gun Lab like a 3 day weekend. And fun we did have. This post is about the new slab for the metal casting area here at Gun Lab. Last weekend we started digging the footers for the new casting area.

I needed a place for my casting furnaces to go.

So Saturday we finished the digging and got the post holes in. We bent re-bar to make the column supports for the gantry I want to put in.

Home made re-bar sopports

This project started with 57 80# bags of concrete. Some here and the rest in the back of the truck.

Once again my little mixer comes into play

Holes are dug and re-bar going in.

Material for the stem wall forms.

Concrete poured and forms going up.

25 more bags for the stem wall. But this will be next Saturday

Fun, fun, fun. that is life at gun lab.

Modifying the spot welder

This is my first water cooled spot welder in the shop. We have used it with good success in the projects that we do here at Gun Lab. However, we needed to make a few modifications to it to allow use to use it more efficiently.

We removed the old lower bar and started making a new bar that is job specific.