GunLab

Machining the FG-42 bi-pod leg female stamping die

This post is about machining the stamping die for the bi-pod leg on a first model FG-42. This will be the third stamping die out of a set of 5 dies. It is also one of the more complex of the dies in the set. I will start with the solid model that was drawn up in solid works after being scanned.

Here are a few pictures of an original bi-pod leg

Here are a few still pictures of the female die.

To give you an idea of the time required to do this die it took a week of design time to take the 3-d scans and convert them into usable solid models. It took another day to write the master cam program. The total time to set up the machine and run the die 5 hours. The material cost was $ 65.00. Tooling cost was $120.00.

We are working on the matching male die and will have a post about that soon. Hope you enjoyed the video and understand the time required to complete a project

FG-42 rear sight base machining video

I posted the still pictures a little while back on making this part. Here is the lathe video on machining the first op.

Just as a quick refresher on the part being made, this is the solid model of the part.

After the first op, which is the lathe op, this is what the part looks like.

I hope you enjoyed the video.

FG-42 first model rear sight

We have been working on the rear sight for the FG-42 first model. The first picture that is a solid model of the entire sight assembly.

The next picture is a picture of the component parts.

The part we are currently working on is the base of the sight.

So now that you have seen the solid model it is now time to show you what the actual machined parts look like and the process that it takes to do it. The first step is to run it on the lathe.

After that there is 5 ops to complete the part.

so now back to step one on the lathe.

Not only is it turned but also drilled the the proper size on the inside.

The next step(op 2) is to cut the flats on the side of the base.

Then op 3 cuts the notches on the other end.

another picture from a slightly different angle.

With op 4 we cut the grove that allows the sight to slide up and down.

Another view.Then the pivot hole is drilled and a slight bevel is cut into one side.

A better shot of the bevel.

The last and final op is to cut the bevel on the opposite side.

This is the first set to be cut.

To give you an idea of the time and money necessary to complete this one small part. The time to solid model this part from the 3-D scans was a couple of hours,time to write the lathe and mill programs and set up the machines was approximately 8 hours. Material cost was 60.00. Run time on the lathe is 5 minutes per piece and run time on the mill is 10 minutes for a total run time on this part at 100 hours. Tooling costs is 200.00. This makes a cost to make this one small part approximately 25.00 each.

I will have a video on making this part in the next week. Thanks for staying tuned in.

AR-10 Sudanese contract

A while back a close friend of mine brought over a parts kit for a Sudanese AR-10. There are no receivers available for this rifle anywhere. However, he did have a cut up receiver. In-addition another friend had sent be some drawings that had been photocopied so many time that done of the dimensions could be read. The real excitement is that I have always wanted an early style AR-10. So while I was waiting for material, tooling or fixtures to be made for the current projects I started another project. that is to design the solid model of the lower receiver. This is that story.
The first thing that was accomplished was to made large prints from the files that were sent of the lower receiver.

Once I had that I started adding dimensions based upon measurement of the cut up one.

You can see the measurement in red on the drawing.

This is the start of the solid model, day one in the process.

The following pictures are the progression of solid modelling the receiver. Keep in mind that this project was only worked on on weekends after we shut down the machines or in the evenings.
A few more pictures of the work after the first day.

This is the model after the second session at the computer.

And again after the third opportunity I had to work on it.

This is after the forth session.

And a cut away of it to show inside dimensions.

This last set of pictures is the final version.

I will be going over every radius, angle,hole and dimension again this weekend to verify that everything is correct with this solid model. I will also be making the changes to make this a semi auto receiver only. The tool list has been generated and I hope to be working on the fixtures and programs soon. Let me know what you think.

updates on the projects

Most of my friends know that I am a little different. Generally when I call or e-mail them to let them know what is going on at gun lab there first comment is always why don’t you just work on one project until you complete it. There is a real good reason that I do not work that way. The first being that when you hit a road block for what ever reason then everything comes to a complete halt. I generally work on 8 to 10 projects at a time.
Some are shop projects that need to be completed to allow me to continue on. Examples of this are painting the shop,

designing and building a new piece of equipment, or doing maintenance that is required. These projects are always in the background and demanding time and money. Something that there is always a shortage of here. The current shop projects are painting and hanging lights for the fab (pressing room) shop.

I am designing a hydraulic barrel fluting machine. The lights just take time to convert a number of 277 lights to 110 and then hang them. The fluting machine is something else. This machine needs to be able to flute to an accurate depth consistently then rotate and do it all again. The hydraulic system also needs to be operational in both directions. This project is taking a little time but needs to be completed to finish the VG1-5 project. The other tooling project that we just finished is the fixture for doing the last of the machining on the upper receiver for the VG1-5.

Some are design or concept projects. These are projects that I would like to make in the future. Generally, it is a great deal of solid modeling. There is some photo shop trickery work done as well. These are the type of projects that take a great deal of time but not much money. Generally the time spent working on these are in the evening or when it is to hot in the shop. Some of these are the lower receiver for the Sudanese contract AR-10. This solid model is now 95% complete and will be finished by this next week.

We are also working on FG-42 first model parts. The rear sight has been gone through and the programs have been written to start making them. The tooling just came in for those parts and they will be on the lathe and mill as soon as material is in.

The major projects are the weapons projects. The VG1-5 is the first and almost complete. We are down to finishing the small parts with only the Barrel and wood work left for major items. However, the small parts in some cases take more time then the larger parts. Ways to hold them have to be designed, tooling has to be made, solid models have to be done and programs have to be written. Everything has to be tested against the rest of the parts that are designed. Some of the weapons projects have hit a stoppage due to costs of material or re-designing of parts. In addition when the temperature gets excessive the power runs out in the shop. During the down periods while we are waiting for material or tooling or if it is to hot to work in the shop then it is off to design projects.
With the above being said I will give you the current update here at Gun Lab.
The original knurling tool that we were using on the VG1-5 front barrel support is just not doing the job properly. My next door neighbor who wants to learn solid modeling, programing and cnc machining has design a new tool.

The only time I have to work on it with him is Saturday afternoon and Sunday.It has been an interesting project for both of us. In the process of making it the computer crashed and died a painful death. Of course there was no backup made to this file. Generally all information is backed up 4 different ways in this shop for that very reason. But not this time. So 60% of the way through completing this project we had to find away to complete it. Hoping to be finished with it on Saturday.
The VG1-5 project needed some special tooling bought and made. This caused a delay of a little over a week. With the upper receiver fixture completed it will be on the HAAS this week as well. I will be posting a more complete write up on the projects in the days to come.Thanks for stopping by.

Firing pin for the VG1-5

With there not being any parts available we have to design and make every part. Some times this leads to re-doing a design several times. The firing pin is a case in point.

The initial design was to use a H&K 91 firing pin that was turn down to fit the VG1-5. The reason for this is that I have a number of them in stock and it is already of the proper material and heat treated. However, it actually takes more machining steps to make it this way then making a new one. The other problem is that it would only leave a small area at the rear of the firing pin for the hammer to hit. The design of the rifle required a much larger area, height of the hammer and location of the firing pin in the bolt.

The next idea was to use a 1911 firing pin. We seriously looked at this idea, but there were still some design set backs as well. I would still have to machine it to fit properly and I would still have to make the other half of the firing pin, but at a much small size.

Original design for second part of two piece firing pin.

The third and final design was to just design and make a completely new design. So, that is what we have done. The initial 5 are made in 4140 that will be heat treated. If after testing they hold up and we have no problems we will make the remainder. If not we will be changing the material specs.

Here is a solid model of what the firing pin should look like in the bolt.

And another view.

Neither of these show the spring. A final solid model.

The notches have not been cut into the rear portion of the firing pin yet. Still working on the design of the fixture for that.

Playing with a home made EDM

I had a small project that need an EDM to accomplish. So it was off to my neighbors house to use his home made EDM. I was making a new folding stock bolt for a L1A1 paratroop rifle that I wanted to make.

Some changes are being made to this edm based upon the results of this project. We are now adding a liner bearing to the Z axis and working on a more accurate X and Y set up. Hope you enjoyed the video.

current update

I know you are all hoping to hear about what happen in the shop today. How we got the Japanese type 99 stamping dies to work or the Fg-42 receivers are finished or that the last of the VG1-5 parts are completed. Well that is not the case. Today’s post is about what is not completed and why.

My wife went to the next doors neighbors house to let his 4 hound out ,as we have every day for the last 4 weeks. Only this time a number of events happened at the same time. This time our dog followed my wife up. this time the gate did not latch properly, this time I was not with her, this time the dogs did not get to know each other as all the other times. So the chain of events went really wrong. This time our neighbors dogs felt threaten by our dog and what happen afterwords was a total disaster. So instead of working on the projects I took our dog to the emergency vet clinic, one of his dogs to the vet clinic and my wife to the emergency room.

Everyone is fine now. My wife spent a number of hours in the hospital getting the dog bites taken care of. our dog has a large number of bites that are stitched up and should be able to walk on his own soon and hopefully one of my neighbors expensive hunting dogs will not lose his sight. All in all it was not a great day. The only good thing about today is that no one died or was hurt beyond repair. Tomorrow is another day and will be better.

The FG-42 butt plate

In this video I show the making of the FG-42 first model butt plate from the making of the dies to the first pressing. This a picture of the before and after of stamping.

http://youtu.be/1Zv2A4J1Od8

I hope you enjoy the video.

This week update.

Once again time has gotten away from me. We are in the shop 7 days a week working on the projects and stuff actually gets accomplished. The updates this week will show the good and the bad that we have had in the last couple of weeks.

First will be the really bad and that is stamping the Japanese type 99 magazine. Our biggest mistake was trying to accomplish to much with a single die. It did not work. Instead of pressing the sheet metal it sheared it instead.

So this lead to redesigning the dies and the process that we are going to use. We have gone to a multiply step process. The first set of dies will just stamp the groves, the second set will bend the sides and the third will set the angle and do the base plate edge. this is a picture of the new first set of dies.

I hope to be back at the press with the new dies this week.

Now a completed project that was fun and interesting. We had a UZi that was brought in for repair. It is a dealer sample converted weapon that would just not work. The first thing we needed to do was machine out the bolt to fit properly.

However with this type of boring bar the chatter and movement was just to great. We changed to a stiffer bar and all was good.

With the bolt problem corrected we still had problems. It would fire one time and then run away. The problem was the excessive movement of the pistol grip. The original grip is set for an 8mm pin and the converted weapon uses a 9mm pin. Once we open the hole in the grip and installed a new proper size pin everything worked like a dream.

We are also working on the VG1-5. A great deal of work was accomplished on the upper receiver. The first 5 which are the test rifles are just about completed. we set up the fixture to all us to cut the majority of the upper receiver.

This allowed us to machine the bottom hole and the slot for the guide slot.

All the guide slots have already been machined.

This how they fit on the receiver.

The cocking handle holes have been drilled.

The rear sight dove tail slots have been cut.In addition to this we also finished the FG-42 butt plate stamping die and started stamping them. That will be the next post and I have to get back into the shop and get to work.

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