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.

rear Sight Assem_sThe next picture is a picture of the component parts.

rear sight assem explode_sThe part we are currently working on is the base of the sight.

FG42-A24 1_s

FG42-A24_sSo 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.

IMG_2278_sAfter that there is 5 ops to complete the part.



so now back to step one on the lathe.

IMG_2299_sNot only is it turned but also drilled the the proper size on the inside.

IMG_2300_sThe next step(op 2) is to cut the flats on the side of the base.

IMG_2302_sThen op 3 cuts the notches on the other end.

IMG_2304_sanother picture from a slightly different angle.

IMG_2305_sWith op 4 we cut the grove that allows the sight to slide up and down.

IMG_2306_sAnother view.IMG_2307_sThen the pivot hole is drilled and a slight bevel is cut into one side.

IMG_2308_sA better shot of the bevel.

IMG_2309_sThe last and final op is to cut the bevel on the opposite side.

IMG_2310_sThis 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.

11 comments to FG-42 first model rear sight

  • Juver

    25 bucks for a small part would be a lot if i was looking for a replacement part
    but now that i know what it need to make it and that its top quality it’s probably worth every penny

  • Pete F.

    YEP! And take that times a hundred several times over for all the other parts of a FG42.

  • Alphawolf45

    Slick, purty…I could make one of those on my manual machines in ’bout 2 days time if I didn’t mess up and have to start over too many times..Hehhhehehh Fun to watch a real professional at work.

    • It is funny that you bring up manual machines. When I started machining about 40 years ago it was all manual machining. Rotary tables on milling machines to cut a radius, sharpers, horizontal milling machines and the such. Then in 2004 I was chatting with a friend and was telling him how excited I was for getting some 1″ plexiglass for nothing and he could not understand why I would want something like that. I explained that I use it to make prototypes with so I could study fit and operation. His next comment was that I still had a drafting table. He was correct. He talked me into solid works, which was a real battle as computers are not my friend. So back to school for me. I took 3 classes in solid works. While at the school I noticed there machine shop and would go in there every chance I got. I decided that I need to see what a cnc machine could do and how hard it would be to do it. So I tool a basic g code writing class. The final project was to draw the ace of spades 3 times making each one progressive larger then the last, write the program and then machine it in aluminum. At that time it took me a day to draw it up, an hour to hand write the program and 10 minutes to set up and touch off the tools. Total machine time to make it with high speed machining. 5 minutes. That was all, just 5 minutes. I looked at that part and thought of how many set ups that I would be require to have if I manually machined it and how long it would take me to do it and I was sold on cnc machining. Now two machining centers,2 cnc milling machine and a cnc lathe later and I still feel the same way.

      • Alphawolf45

        You have manual machines as well or just cnc?

        I am just now learning to draw solids and don’t have the hang of it yet.(Friend gave me his copy of BobCad) Yesterday another friend come over with 8 roller guides from a complex custom built commercial wood working machine ..We sat there and I quickly drew the new contours he wanted in 2-D AutoCAD and today I’ll cut them with my old cnc mill. I’ve had cncs since 2004 but there is plenty I havent learned yet.. I never took any classes. Learn a lot by observing others……Yeah and I am ’bout due a newer cnc milling machine..

  • Chuck

    I know bob cad is cheap but if you ever have the opportunity I would get Solid works. I have a friend that had bob cad,as did I, but when I showed him how easy and fast solid works is compared to bob cad he converted that day.What cam program are you using. We use master cam for the machining centers and the lathe, however for the cnc mills I use del cam. Great program, easy to use and even I can write the post processor for my mills.
    I thought you were thinking about a trip to Phoenix?

  • Alphawolf45

    Don’t think it was I that was planning trip to Phoenix…..

    I am not trying to earn any real serious money from my 4400 sq. ft hobby workshop.. I am successfully earning nearly nothing from my home workshop. Still I enjoy occasionally getting new toys for the shop.. My Plasma burner died last week, Got a new plasma torch coming by FedEx tomorrow.. I manage to add another toy or two to the shop every year- not going to pop for expensive software unless something changes and I cant avoid it. BobCad is substantially better than what I have been using for years.. Certainly there is always something better..

    You didn’t answer- You still have manual Mill and lathes or just the cnc machines? I will never give up my manual machines.

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