Jump to content

FG42 build


Recommended Posts

I think i've gotten far enough along on this build to finally warrant a post on progress...anyway, here's my take on the FG42 (or at least what i have so far).
I wouldn't have started this build if i wasn't able to buy a resin/fiberglass kit of an FG42 from indonesia. 
This is the first time i've used a cad program for a build.  I was just a math paper and ruler sort of guy before, sometimes not even.  But i got to try my hand a Google Sketchup, and man, was i hooked.  Extremely easy to learn and less trial by fire come build time.  So here is the design phase, with a sten gearbox and hop up as the base:
The receiver would have to be much bigger to accommodate the gearbox.  One could fit a modified version 3 gearbox in the buttstock and custom build a very long nozzle and hop up to keep the dimensions closer to reality but i did not want to mess around with potential leaks and low power later on.  I chose the sten gearbox because the nozzle and tappet is centrally located and the motor is straight.  I will be removing the sten trigger and hooking up a microswitch.  Dimensions of the receiver take into account existing pipe and box steel dimensions.  
The great thing about using a cad program is that i can actually work on designing other components while waiting for the machine shop to finish other stuff.  So while the barrel and other bits are being machined, i can work on the receiver, stock, and handguard...
Here's what i have so far...
At first i was hoping to use parts from the kit directly but unfortunately, it's made of very thin and brittle fiberglass.  I had the handguard and bipod copied in high impact fiberglass.  I still have to adjust the size of the stock to fit the larger receiver then that's going to be done in more durable fiberglass as well.  I'll be using m14 mags for this.  I chose m14 mags mainly because king arms has a cheap set of 5 midcaps in plastic, which will be easier to modify.  They will be going into the magwell in a reversed orientation though.
compared with the kit:
front and rear sights, muzzle made out of aluminium


Bayonet lug and gastube/bipod mount


High impact fiberglass furniture.  The buttstock had to be enlarged to fit the fatter receiver and to accommodate the rear of the gearbox.  Battery will be stored in the stock as well.


Trigger mech prototype made out of Sintra board, utilizing a micro switch. It seems sturdy enough as it is so i may defer translating it into aluminium sheet.



More to come...

Link to post
Share on other sites


All externals fitted together nice and snug, locked in place.

Bipod does not swivel out though.  They have to be unscrewed and repositioned for deployment.  I won't be using them except maybe for picture taking though.

Made the grips out of sintraboard and epoxied them in place.

Epoxied the top of the receiver (rear sight mount) and hop adjust.  Will have to sand to make flush against the receiver once it fully cures.  The front and rear sites do not fold and are fixed in place (mainly due to laziness on my part).  The hop adjust came from an m14.  








Still to do:

Still need to obtain a 600mm inner barrel

adjust the nozzle

wire in the microswitch and mosfet without active breaking


Link to post
Share on other sites

It's all wired up and shoots!  It's aliiiiive!  I hope the micro switch lasts with the non-active breaking mosfet to protect it...


Still have to get a longer inner barrel, adjust the nozzle to the right length, and do some durability mods to the gearbox (metal bushings, spring guide with bearings, corner mods, maybe a sorbo pad, aoe mods.


Then paint!
Link to post
Share on other sites

Thanks!  Almost done!



Found an old 550mm barrel and decided to use that instead of buying a new one.  
Modified the 1st release AGM sten hop unit to make it adjustable.
I had to find a longer nozzle because the securing holes for the gearbox were drilled 2mm to far back.  So i added 2mm to the hop-up chamber where it rests against the gearbox, used an longer nozzle i found in my parts box (i don't remember from what aeg) and sanded it to the right length.  It should be long enough to seal with the hop rubber but short enough to allow bbs to feed.  I also filed the front face of the tappet in order for the nozzle to sit a bit more forward.  I replaced the plastic bushings with 6mm steel ones and the plastic spring guide with a version 3 with bearings.
Shoots great!  Without any misfeeds, despite the custom nozzle length.  Great trigger response due to the mosfet.
All that's left to do is some of the cosmetics and paint!
Link to post
Share on other sites
Here it is!  My take on the FG42 type 1


To summarize:

Receiver is 1mm sheet steel folded and welded to two steel tubes with a 32mm id.

Iron sights, barrel, muzzle, bayonet lug, bipod mount/gas tube are aluminium.

Bipod, handguard, buttstock are fiberglass.

Internals: version 7 gearbox, modified nozzle, sten motorcage, sten hop chamber, microswitch, mosfet without AB.

Magazine: King arms M14 midcaps


Again, i wouldn't have been able to build this without this kit:


Here are the pics:







Unfortunately, because of the local gunban (election season over here), outdoor pics will have to wait...in the meantime here's a poor indoor shot just for size reference


Link to post
Share on other sites
  • 2 weeks later...
  • 3 weeks later...

Stunning work jimmiroquai, beautiful job.


I was asked if I could make one a year or so ago, but without access to a real one (or 1:1 model) to measure, and because of the uniqueness of the parts to make, I decided it wasn't feasible/practical (not without putting a massive price-tag on it anyway).

I might have to think again now... :mellow: 

Link to post
Share on other sites
  • 3 months later...

Sorry for the semi-necro post but the election gun ban just ended over here and yesterday was the first time i got to test this baby out. Hop adjustment was a little fiddly, But iron sights were dead on the spot. smiley.png Handles great too. Tacticool carry is just so natural with this gun that i can't think of anyway else to carry it.





Link to post
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use and the use of session cookies.