GunLab (KnownHost) » pattern making

Gun Lab update

Chuck — Fri, 19 Jun 2015 08:00:52 +0000

No posts for the last couple of days. Sorry about that but with the temperature hovering around 112 and working outside from 5:30 am until 7 or 8pm I am just out of steam.

Here are the updates though. The bending and stamping die for the AR-180B bolt hold open device in just about complete and we will be working on that this weekend. I have to finish hand tapping the safety shaft then it will be off to heat treat after that.

I have been spending a great deal of time drawing up parts in solid works to run on the cnc router. I am drawing up some basic patterns to machine for use in the casting shop, killing two birds with one stone.

Starting with a simple pattern.

To what is a complex part to machine and cast. This piece in the next two pictures has a complex curve between the two columns.

To a two piece pattern.

I was able to write and run a program in dry run on the wire edm. Still working on cleaning the tank and flushing out the system, more to be accomplished on this this weekend.

Playing with the cnc router

Chuck — Tue, 19 May 2015 08:00:48 +0000

Most of Saturday morning was spent with trying to get a feel of how to use the cnc router. The operating system is Mach 3 which is totally different then any other system in the shop. A number of items were learned during this operating time. The first thing was the e-stop is wired in wrong and needs to be fixed. The program would not single block, once the program was started it ran until the end. This problem has to be determined and fixed. The most important improvement has to be a better way to hold down material while machining. I am thinking of making a vacuum table to solve this problem. For our test run I design a basic part that involved no surfacing, still having a little trouble with that in Del-cam. This is the drawing in solid works.

Basically the program that was written to bring the stock to size and radius the corners, ten face it to reduce the thickness and finally cut two pockets one round at a depth of .250 and one square at a depth of .100.

Here is the video of the operation as it was performed.

As a first test run things went well. There is still a lot to learn about Mach 3 as well as fixing some of the glitches we came across.

There was no good way to locate the part in relation to X and Y so the laser edge finder was used.

The MDF board has not been mounted yet so temporary clamps were used. Working on that.

The final product does not look half bad. Del-Cam does not have a wood setting. The next part we will manually program that in.

In the long run this will be a very useful piece of equipment in the shop for making stocks and grips as well as making patterns for metal casting.

New tool for the wood shop

Chuck — Wed, 18 Mar 2015 08:00:51 +0000

A while back a gent passed away and his wife was left with a cnc router. A friend of mine had loaned him the money for the router so the wife let him take the router as payement. Long story short he had no use for the router and a little trading went on and now this sets in my wood shop.

The table is 3’x5′ which is a perfect size for my little wood shop. All is not perfect though.As you can see there is no dust collector cabinet. This is something that has to be fixed as this little machine will put out more saw dust then I can clean in a week. The next problem is the support stand. It was not part of the original machine but something that was added later and poorly done as well. To give you an idea this is the cross support.

It was an aluminum extrusion for a window or door that was cut away to kind of fit and then screwed on to the base leg.

The aluminum leg would be fine if they were accurately marked and machines to fit the frame, but they were not. In addition they are not adjustable to allow proper leveling.

The good news is that it comes with a lot of tooling and tie downs and has mach3. I have had the opportunity to run this machine and it works great. The only machine improvement that I am going to make is raise the z axis to all the use of a 4th axis.

A few more pictures of the new toy.

I am hoping that this will be a great time saver for the stocks we have to make on the VG1-5 and 05 rifles as well as pattern making for the metal casting I need to do. For those of you that will ask, yes I could have used one of the cnc mills or machining centers to cut wood and I have. The problem with that is the oil that covers the machine tools is not good for the wood parts and the saw dust is not good for the coolant systems.

Making the miniture Gardner Gun “The Receiver”

Chuck — Wed, 31 Dec 2014 08:00:02 +0000

In this post we will start with the making of a miniature Gardner Gun. The very first step that Joe did was to find someone with a Gardner Gun that would allow him to study and measure it. That was no easy task but one that he prevailed at. Joe spent a number of months just taking measurements of a full size Pratt and Whitney model Gardner Guns and converting them into a solid model in solid works. After gathering the information on a full size weapon he started the process of converting it to 22lr. His first attempt upon completion of the drawings was to make up a wooden mock up to get the basic concept to work from.

With this he had a starting point. Now it was time to convert all the data he had collected into semi working plastic model. This allowed for the checking of dimensions and operation of the weapon. It was also hoped that this would also provide the pattern for the castings. That would not be the case.

It was now time to self-educate himself on wooden pattern making and metal shrinkage. After a number, it took three attempts, of patterns he finally came up with a design that would cast properly. A number of problems that you will generally not find in books occurred. A few of the examples are getting the metal to flow properly, is the casting area to thin. How do you hold the cast part to machine it. Is there enough metal to machine away the rough surface. Is there to much metal causing extra machine time. Is the metal going to sringe to much causing an out of spec casting.

This is the wood pattern for the outside shape of the Gardner gun.

This pattern is for making the core mold. It took a number of attempts for this core mould as well

After casting the raw bronze casting with the sprues cut off would look like this.

In our next post we will go into the work necessary to machine it.

Making the Gardner gun Part 1

Chuck — Tue, 18 Nov 2014 08:00:57 +0000

I enjoy making things, specifically guns and any thing associated with making guns. I also enjoy chatting with people who make guns or any thing dealing with that. I also love mechanical machine guns. That leads us to today’s topic.

A friend of mine really wanted a miniature Gardner gun and with none available took it upon himself to make one. In fact not only one but a number of them. He has since sold the complete operation and tooling but this is a little write up of the process it took to do it. I really wanted one of these and to complete the project, there was just a little problem, money. The amount of work required to make this weapon much less a miniature one was immense. There were no usable blue prints to work from. There were no patterns available. So to complete this project he had to first find a gun, reverse engineer it, draw it up in a modeling program ,then reduce all the components to make it in 22lr. This was a task only one person would even think of doing, Papa Joe.

The original Gardner guns were made in 577-450, 43 Spanish, 11mm dutch and just about every other military black powder cartridge and 45-70 then finally in 303 British and 6.5 Dutch, can’t remember where I saw this at. The weapon was used up to WW1 by the Dutch. It was even copied by the Nepalese in the form of the Bira Gun. It is a manually operated machine gun that came in one,two and five barrel versions.

On wheeled mounts.

A two barrel version with no jacket.

A two barrel version with a jacket.

This is what the hole in the top of a water cooled version looks like.

Then to the 5 barrel version.

A nice example.

It was a beautifully made piece of art. There are a number of varieties, as I have shown you some come with no jackets, some come with solid jackets and some come with open top water jackets. It is currently being reproduce by two different companies both as a bronze casting and as a fabricated steel one that is plated. No mater which model or style you look at they are just great. It was even made as a belt fed gun.

Papa Joe took it upon himself to make the most complicated one possible. The two barrel full jacketed water cooled version. Part 2 will continue on with this saga and go into a little more history.