GunLab (KnownHost) » CNC machining

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.

Why it is necessary to run a test part after changes to the program

Chuck — Fri, 27 Feb 2026 23:15:29 +0000

A number of changes were made to the Sudanese AR-10 lower receiver. Selector stops were added and a new profiling program was used to allow for a better finish around a few areas of the receiver. Then a second lower was machined out of 6061 to verify the changes. During the process of machining a few issues were notes. The first is that with the new tool path it left on a thin section of metal.

The magazine release button also changed from an inside cut to and outside cut.

The other issue that was found was that the selector stops were located in the wrong spot.

All the issues have been corrected and checked. Next is to design a logo and write the printing program then start making Sudanese lower semi receivers.

Machining the Sudanese lower receiver op.2 and op3

Chuck — Sun, 08 Feb 2026 00:49:38 +0000

With op 1 completed it is now time to work on op 2 and 3. First a fixture needed to be machined to hold the machined receiver to all finishing the other side.

The machined op1 piece was set in the fixture and tighten down

All the holes were drilled in op1 so now the bottom was milled off and the receiver was contoured.

When the second side was complete receiver was removed and debured and parts were checked for proper fit,

The magazine release was checked for proper fit.

Op 3 was conducted, out of house, This is where the magazine housing was edm. it was then checked with a number of magazines to verify proper fit.

Next post will be about op4

CNC router update

Chuck — Mon, 13 Mar 2017 08:00:01 +0000

Over the last few weekend I have been working on trying to get the CNC router completed thus allowing me to finish the stocks and hand guards for the VG1-5 rifle. For every step forward there seems to have been 3 steps back. It is hard to believe that it has been over a year on and off that I have been working on this machine and just when I thought I was finished along comes another problem.

So lets start this long story.

It started with getting the router home and actually operating it. There were some problems noted right off. The first was the table that it sat on. There was way to much vibration for any kind of accuracy. These are the pictures of the old frame.

Parts of it were old window frames

So a new frame was design and built for the router. 80-20 aluminum extrusions were machined for the frame.

The table was assembled.

Custom supports were made to hold the cnc router on the table.

Now it was ready to move the router over.

Angle brackets and supports added to reduce vibration.

The next issue that had to be dealt with was his wiring. It was a disaster.

While the machine was able to operate there was no accuracy and no way to trouble shoot problems. It was then decided to make an entirely new control panel.

Everything had its own place and wiring could be traced out to locate problems.

We also changed out the break out board to a smoothie board.

At this point you would think everything would be easy and simple and I could move forward quickly. That would not be the case time and again. Problems started showing up fairly quickly. From simple items like changing from plastic side panels

to aluminum. This helped with the strength and well as allowing allowing a method of attaching components.

The next issue that came about was changing the limit switch brackets. The builder used strips of bent aluminum that would actually move every tine the X,Y or Z axis touched then.

Two of them were actually tie-wrapped in place.

New mounting brackets were made and installed.

These were machined from aluminum stock to allow no movement.

However when it came to the Z axis we decided to go with micro switches instead of the push button type.

This may be an option for all the limit switches in the future.

The next item on the list was the wire troughs. The previous owner used on 1/2 lengths of flexible wire troughs then he used an aluminum cover that he glued and tie-wrapped on the housing.

I bought some more the the original wire troughs and attached it properly to minimize movement.

The final task will be to tie-wrap them all down.

An air system was design and added to the router.

From the regulator and filter.

To the solenoid switches and manifold.

The power was run to a plug in box as well. In addition a couple of extra control circuits were added to allow for added features.

So now comes the moment of truth. We had already,with the help of Walley, tested the X axis motor control. With the limit switches wired in and the other axis wire up we were ready to calibrate the router. As one final test I was operating the Z axis with a battery operated drill motor when all of a sudden it just fell off. I mean to say that the complete drive assembly just dropped. This is when we noticed a completely new set of issues.

To attach the ball lead screw to the motor coupler he cut the threads off.

Then he used the coupler to act as a thrust plate and attachment to the motor. Off course to do this he needed to grind the heck out it as it wanted to rub against the housing.

He then cut the motor shaft to allow everything to go together.

You can see just how much of the shaft he cut away.

This is what he started with.

To correct the Z axis problems it had to be redesign.

Still using the original spacer which was way to short.

A new spacer and housing was design and machined.

This new housing will allow for a correct height for the shaft, bearing, thrust block and coupler.

This is it for now as we wait for the new ball lead screw. This is also the last 3 weekends of work, not to include the fab shop and library addition. more on those later.

More work being done on the cnc router

Chuck — Thu, 23 Jun 2016 12:47:11 +0000

With the wiring completed on the angle connector plate

The next item to be made is the side panel. This is where the fans and angle plate attach to.

These are the pictures of it being machined on the HAAS machining center.

Everything starts as a solid model and then a drawing to work from.

Even with solid models and drawings the components are checked for proper fit.

The side plate will be completed by today and this weekend installed on the machine and I will commence wiring everything up.

MP-44 Trunion op7 , 8 and 9

Chuck — Thu, 21 Apr 2016 08:00:46 +0000

With these last three operations we will have completed the work on the cnc machining center.

You can see the process of rough machining the bottom of the curve for the trunion. This op also machined the complete magazine well out.

A good side view of the rough machining of the curve.

All the trunions finished with this operation.

The basic set up to complete this op.

This is op 8. All we are doing in this step is to finish cut the curve under the trunion.

OP 9 then goes in and cuts the top of the trunion.

These two pictures shows the top roughed out just prior to the finish pass.

This is how they look after the finish pass.

All the trunions after the finish of op 9

A close up of the trunions.

The next step in the manual mill

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.

Working on the MP-44 trunions.

Chuck — Thu, 17 Mar 2016 08:00:31 +0000

We have started on Pete’s, a friend of gun lab, new 4140 MP-44 trunions. This series of videos and posts is the process we used to make them.

First the video.

Here are the pictures going over the changes and the steps we took.

We needed to change the depth of cut for the locking shoulder

We also did not put in the chamfer on the back of the block

Set up for ops one and two.

All of the trunions have now gone through ops one and two

Op 3

the bored hole and start of gas tube cut out.

you can see the finish of the bored hole and the step for the barrel

All the 4140 and test trunions have now completed op 3.

OP 4 is coming up and will be next post on the MP-44 trunions.

Working on the VG1-5 bolt

Chuck — Fri, 06 Nov 2015 13:32:41 +0000

The last post on the bolt was when we completed the lathe work on it. This left us with a turned bolt with the firing pin hole drilled and bored.

A fixture was designed to allow us to machine the bolt at the different angles and still keep everything aligned as it should be.

It is placed in the vise against a stop and the hole for the base of the cartridge is machined as is the spring for the extractor.

Another view of the same operation.

Next an angle adapter is installed in the vise to allow the bolt fixture to set against it. This allow us to machine the opening for the extractor.

With this photo you can see the angle of the machined opening.

Close up as it sets in the machineCompleted bolts for this operation.

The last few to be completed today.

VG1-5 update Machining the lower receiver

Chuck — Thu, 29 Oct 2015 08:00:15 +0000

This post will go through the steps necessary to machine one of the lower receiver. I was going to do a video, but there was not much to see with the coolant on.

If you remember the last post on the lower receiver we had finished welding it up and it looked like this.

Now comes the part where we remove everything that is not part of the rifle.

First a couple of pictures of the fixture that was made to do machining. You can see that this fixture will support and clamp in the receiver securely.

What we are going to do is clamp a receiver into the fixture.

The first step is to install a center support for the receiver.

The it is clamped into the fixture.

We do this to mark it so the excess can be plasma cut off prior to machining.

You can see the magic marker on the sheet metal where it was plasma cut. You can also see the 3 holes that were drilled to allow clamping the front and rear clamping blocks

Now it is back into the fixture for machining.

After a slow and careful machining op, sheet metal has a tendency to grab the end mill and come out of the fixture. We are finished with this phase.

A couple of close up pictures of the receiver after machining but still in the fixture.

This is how it looks coming out of the fixture and prior to de-buring.

This how they look after the initial de-buring.

After the receiver is cleaned up a final machining operation is conducted on the manual milling machine to clean up the inner area of the receiver.

With this operation we have gone from rough weld up to a finished machined part ready for the next operation.