Matrix (S&T/AGM) MG42 - In-depth Look / Upgrade Blog

[Cain Mkii]

Thank you kentsui
Any measurements would be of great help.
Lenght, width and height of the inside where the gearbox sit will give me an idea of the empty space I can use to fit it in
If you could add the measurements of the MG42 upper part of the gearbox, it would be perfect

[Cain Mkii]

Here are the M249 gearbox measurements:

[KenTsui]

My apologies. I keep forgetting about the measurements for the last few days. I will try to remember to do it tonight.

[KenTsui]

Well, I finally took some measurements. Let me know what else you need; I wasn't sure how much detail you want.



25.6 mm is the width of the gearbox
200 mm is the length of the gearbox
47.2 mm is the width of the gearbox with the extension brackets installed
40.2 mm is the height of the gearbox





22.4 mm is the width of the rectangular opening
38.8 mm is the approximate depth of the receiver. Note that the corners of the inside are chamfered. I'm guessing about 1-2 mm radius.
120.4 mm is the length of the rectangular opening, not including the round notch.
50.7 mm is the inside width of the receiver
1.3 mm is the approximate height of the raised screw holes, from the inside wall.


There is a small gap between the gearbox and the receiver walls when installed. It's not an error in measurement.

[BlueAirsofttv]

Originally Posted by Siegfried

I want to show few photos of my own project. Upper gearbox part and hop-up chamber.

Upper gearbox part. There is d16t aluminum alloy, made by cnc machine tool. Front side is thickened by 3mm. The groove for the cylinder is made for bore-up set - 70mm. External dimensions of a detail correspond to the basic sizes.

Upper gearbox part with internal parts


Hop-up chamber. D16T aluminum alloy. There is the ledge for an insert in gearbox, the hop-up chamber is executed so air nozle it was possible to establish less then basic 29mm, i set nozle for G36 (25.5 - 26mm).
In my basic hop-up the part for connection with gearbox is removed, as a result of the first experiments =)
The entrance opening for a platform of giving of bbs ("square platform")is made with the minimum admission by the sizes. As a result it turned out to avoid leak of air in this connection.


As it looks in assembled form. There is the first version of upper gearbox.


There is a link to my "video" (may 2015) with firing MG42 with stock motor. I changed my M135 spring to M170 in video. I shoot more than 2000 bb during test (considering out of video tests). It was fine work during short turns and long lines of shots, no troubleshoting with upper gearbox part after test and through test. Sorry for non-english video, i want to make a copy with english text.

https://www.youtube.com/watch?v=yqCO...tailpage#t=158

I would like to answer any question. If someone want the same stuff to have in own AGM MG42, I can make the offer by rules of this forum.
With best regard, Siegfried
Belarus, Minsk.

I would be very interested in getting a C&C hop up and the upper shell. I posted in your video but I have not heard anything back.