GunLab (KnownHost) » engineering design

Shop Update- The CNC Router

Chuck — Fri, 03 Apr 2026 17:06:41 +0000

This is a saga of the CNC router. The router was built here in the shop and it was used to make the stock and handguards for the VG1-5. 5 years ago I was running a batch of parts and hit an over travel stop. When this happen I just shut off the machine as something had come up and I could not finish the parts run. When I got bad to working on the router I could not get the machine to do anything. I kept getting this alarm code.

So every week or so I would try and get the machine o run. I checked the limit switches, got on to boards to see if someone else had a similar issue and tried to clear the computer. Nothing worked, nothing. It was at this point that I decided to correct the reason I got the problem in the first place. I started building a cabinet around the router and install a built in dust collector system.

I did the build with 80-20aluminum extrusions and plexiglass. Both of these I had from recycle and demo jobs.

So I carefully design the cabinet and built it to enclose the router.

I put door and access points to allow me to change and test tools and touch them off. It also allows for material to be set up and product to be taken out. I finished the top cover

with a dust collector access port. Now came time to actually get the cnc router working again. Last week I traced and tested every wire and switch. I found the issue and the router is back up and working.

The big mistake came when I started to operate the machine and realized that I made the cabinet to small.

You can see that I did not leave enough room for the X and Y axis cable rack.

The time has come for me to re-build the cabinet. 2″ in the Yaxis and 7″ longer in the X axis.

Some days you just wake up on the wrong side of the table. Back to the design board and fix it to allow me to go back to using it.

The Mauser 1917 trench carbine receiver

Chuck — Tue, 24 Mar 2026 15:03:08 +0000

I have reverse engineered most the lower receiver in Fusion 360 and will print the first model this week. This is the first print so I can test my solid model. Using the Bambu P2S printer I will print a 3D model. There are a number of modifications that will needed to be made, but I can check my initial model.

The 3D print is completed and as suspected there are a couple of changes that need to be made.

But the overall model is on.

The issues that I have found deal with the measurements and using photos that were not an exact 90 degrees. Not comes the fun part of making minor changes to correct the issues.

More on the Sudanese AR-10

Chuck — Fri, 20 Mar 2026 17:25:45 +0000

With the last test model machined I started putting the lower together and a number of issues were noted. The receiver dimension is correct for the holes, magazine release, magazine well and overall length and width. the magazine button and release lever are not deep enough.

These are the noted problems.

The first one is a very slight radius issue on the rear of the receiver just prior to the buffer tube

The second issue concerns the magazine release lever. this needs to be cut deeper to allow proper fit.

The third issue deals with the hole for the selector. There is a slight inset in the receiver to all the selector to set properly and this needs to be cut in. This is how it looks on the original.

And you can see it is missing on my test receiver.

The last issue is raised portion of the receiver around the magazine release. On my receiver it extends to far over and does not line up with the upper receiver properly.

With some minor changes to the machining program I hope to correct these issues.

Mauser V9000 trench rifle

Chuck — Wed, 04 Mar 2026 03:21:28 +0000

While doing research on the 1917 trench carbine I came across a rifle that I have never seen or even heard of. The V9000. There is a video on YouTube posted by LAI Publications. I just fell for this cute carbine.

It also dissembles and the stock comes off.

There was a print of it taken apart.

I thank LAI publications for posting about this rare and interesting weapon. I decided that I need one in my collection. There is no chance of buying one and it is full auto so actually making one that is exact is out of the question. However I can make a semi auto one. As with all of my projects I need to design it from scratch. With that in mind I have started just that, but I am making a few changes to the design. First I will make it in 9mm and not in 7.62×25 Mauser. Second, I am going to make it to use a different magazine. I have never been a fan of the Mauser style magazine. they are expensive, a number of the ones I have do no fit properly and they are hard to fine.

My favorite magazine for my Broomhandle projects is the Finnish M/20 smg magazine. They are available at Apex gun parts.

It is a great magazine that I will cut down to 25 rds.

The first step was to design the lower receiver to use a M/20 magazine. I started this process with using a cut Chinese Schnellfeuer lower.

I was able to make a basic solid model but with the proper dimensions for the M/20 magazine.

There is a number of features missing from this model but, it is just a starting point. So I printed it out on m Bambu P2S 3D printer.

I was able to check to see if my magazine housing was dimension properly, and it was.

The next print will have the magazine release button. The rear of the receiver needs to be corrected. the bottom of the receiver is to thick and it receiver needs to have internal dimensions reduced. I am currently working on the second model receiver and should have it completed by the end of next weekend. I also need to add the dove tail slot in the front of the receiver

Update on the VG1-5 project

Chuck — Thu, 30 Jun 2016 08:00:41 +0000

We have been working on the fire control group and once again have made a few changes for more reliable operation and safety. We continue to have issues with the disconnector operating properly. There were issues with the hammer spring improperly contacting the disconnector. An additional problem came about with insufficient spring pressure to hold it in it’s proper position.

This is the old style of disconnector compared to the new style.

The old version of the fire control group. There was a great deal of problem to get the disconnector to work properly.

The part as laser cut

Solid models of the fixture.

fixture for machining the disconnector.

After the first machining operation

The finished part with cut outs for the hammer spring and

From start to finish now to de-bur and heat treat.

This is the fire control group with the problems worked out.

The MG-09 light machinegun

Chuck — Wed, 27 Apr 2016 08:00:07 +0000

In answering question concerning the post on the AR-10 belt fed light machine gun Ihave spent some time going through the ” The Armalite AR-10″ book. On page 314 of the book is a picture of a MG-09 light machine gun. The funny thing is that I had just seem that same weapon. It was on my back up hard drive and it was in a file of pictures of weapons that I had taken a while back. I had no idea what the weapon was, but that it just looked interesting so I snapped a few pictures of it.

This weapon bears a close resemblance to the T44 light machine gun designed by the United States after WW2.

These are the pictures I have of the MG-09. If you read the section in the book on page 313 and 314 it answers a few questions on the weapon.

A right side view

Left side view

A close up right side view of this weapon

The left side of the weapon with the side cover open

A close up view of the feed system.

The feed cover assembly looks like a very simplified version of a cross between a MG-34 and MG-42 top cover. An interesting design that never got beyond a working non firing mock up. Mock ups like cut away guns are a great way to study small arms design.

Machining the MP-44 trunions op 5

Chuck — Fri, 25 Mar 2016 08:00:29 +0000

With this post I am going over a few of the problems that have occurred during the machining of op5 on the 4140 hardened trunions. We ran into a snag while doing this op. A problem that did not occur on the 1018 steel parts.

A quick video discussing the problem and solution.

The problem is that we just broke our second 4″ solid carbide end mill.

This one being brand new.. Something need to change in the process that we were using to make the 4140 trunions. The problem as far as we can determine is chip load up that did not happen while cutting the 1018 blocks. Now the new procedure is to cut a slot down the top of the trunion.

This slot and the next op will allow for more coolant flow into the part and better chip removal away from the cutter.

This is the set up for the this op.

Basic and very functional.

This new procedure was just started and we are well on the way to being back on schedule.

This new method as reduces the chatter that we had to deal with.

Building an MP-44 semi part 2

Chuck — Mon, 21 Mar 2016 08:00:35 +0000

This is the second in a series of post of Pete, a friend of gun lab, building his semi-auto MP-44. From our previous post you could see the absolutely dismal condition of the cut up receiver pieces that Pete had to work with.

You can see from these pictures that there was no back section. So the only answer for Pete was to design the tooling and make a new rear section. This is that post.

In this photo you can see the style of the female die with the cuts for the ribs to be pressed in.

As with all stamping work to obtain the best possible product you must have a flat that is the same and you must have a method of properly locating that flat.

This male stamping die is much more complicated to make then most people think. All this tooling was made on a manual vertical mill.

With any press tool you have to have guide and alignment pins to obtain a quality product.

Pete does all his pressing on a simple shop press.

To fabricate the rear pieces it take multiply set up’s.

Some real nice tooling to make his rear section.

This is not a simple process to make the rear sections.

You can see for this final photo the quality of work that Pete produces.

If anyone is interested in a replacement section drop me a comment and I will forward it to Pete. He has a few of these left.

Answers to the post of 11-29

Chuck — Tue, 01 Dec 2015 14:14:35 +0000

The first question that would needed to be answered is what do all these parts have in common. That answer would be up coming projects at Gun Lab.

The Cetme, H&K, 05 , G-41 G-43 and 03 pictures is for the 05 project we are working on. The fire control group is changing to be a copy of the 03 rifle. The safety will be going back to a G-41/G-43/03 type. The magazine will be more in line with The G-43 /03 type. There is a great deal of design work that needs to go on to make the rifle.

The AR-10 bolt is for the AR-16 rifle that is next on the list of rifles that we will be building.

I like single shot rifles and with a friend on mine (Orin) we are working on making usable drawings of a number of them.

I have a Scottie rifle that someone sporterized the stock. Ian from forgotten weapons let me borrow his parts so I could make the correct ones for my rifle.

The destroyer and AR-70 parts are for my rifles and needed to be repaired and measured.

Last but not least is the EM-2 bolt which is being reversed engineered to try and correct a few problems with the rifle design.

On to the pictures.

Interesting AR-18 tool

Chuck — Mon, 05 Oct 2015 08:00:19 +0000

It is not often that most people think how something was done in the “Old Days” but I do. Lots of times you can not reproduce a part using modern machinery with a great deal of work. The “Old Days” I am talking about is not the 1600,1700, 1800, but the middle 1900’s. I just received some real interesting pictures on making the AR-18 bolt carrier. Did you ever thing how they made the bolt cam track on an early AR-18. This is the days before cnc machining. This is the tool used to make the cam in the bolt carrier for the first prototype rifles.

Sorry for the quality of the pictures, it is how they cam. If anyone knows the were about of this tool please contact me. I would like to take better pictures.