FG42 build in progress

[jimmiroquai]

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.
Link: x5model.blogspot.com/search/label/1%3A1%20Fallschirmj%C3%A4gergewehr%20FG42

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:


Much more to come...

[jimmiroquai]

front and rear sights, muzzle

[Flippy]

Will be nice, I'm sure!!!

How much was the resin modell gun (I saw one in the past /evilbay for about 250USD+ship')?

I'm terribly said that there are absolut no diagrams, blueprints about the 2nd (later) type. That woud be much easier to bild.

[LϟϟAH1944]

yes, how much are the replicas? I saw them a while ago, but never saw any price.

[jimmiroquai]

I got mine for about 145USD unassembled and unpainted, without the metal tubing for the barrel. There aren't any blueprints for the type 1 either. I just downloaded a lot of pictures, researched how long the real one was, and extrapolated from there. Made my own blueprints on Google Sketchup. When i finally got the kit and checked it against my measurements, it was almost spot on.

Actually, a build of the 2nd type would pretty much have the same difficulties of the 1st type. I think the main problem of an FG42 build is that the magazine is located behind the trigger. That and the receiver is tiny.

[Flippy]

Side diagram, receiver diagram, parts diagram (if only all would be type II.):



I think the 2nd type has larger receiver (so V7 may fit without modification), + it has wood stock, non foldable grip, which makes it much "easier" (relative).

[LϟϟAH1944]

Dec 22, 2012 19:27:04 GMT -5 jimmiroquai said:

I got mine for about 145USD unassembled and unpainted, without the metal tubing for the barrel. There aren't any blueprints for the type 1 either. I just downloaded a lot of pictures, researched how long the real one was, and extrapolated from there. Made my own blueprints on Google Sketchup. When i finally got the kit and checked it against my measurements, it was almost spot on.

Actually, a build of the 2nd type would pretty much have the same difficulties of the 1st type. I think the main problem of an FG42 build is that the magazine is located behind the trigger. That and the receiver is tiny.

145? thats not bad. how do you order? For an airsoft FG, the easiest way is to convert a pistol, unrealistic, but simple.

[jimmiroquai]

Update:



I'm having a bit of trouble trying to design the butt stock though. The plan is to enlarge the current resin/fiberglass one to fit the gearbox and the back end of the receiver then recast in stronger weave fiberglass. But i'm stuck as how to secure this to the metal receiver in a durable way...any ideas?

[stuka]

lots of super glue XD, looks nice so far though

[brownien]

Depends on where the battery will go! If you end up having the buttstock telescope over the rear of the reciever, you could simply weld a nut to the rear of the reciever, and drill a cooresponding hole through the buttstock, and attach it with a long bolt. This would give lateral stability to the stock and would keep you from relying on the thin walls of the stock to overcome any such forces. Goodluck to you! She looks real perty! ;D

[HornetWSO]

you could perhaps cast an MP5 like adapter into the fiberglass stock, just a thought.

[jimmiroquai]

Basic externals. Now to secure them all together and fit the internals...

[brownien]

Das ist beautiful! great work!

[knights52]

Ja, es ist sehr schoen

[jimmiroquai]

Thanks!

Worked on the trigger mech today. Main switch is a microswitch. Made the prototype mechanism out of Sintra board. It seems sturdy enough as it is so i may defer translating it into aluminium sheet.

[jeeperscreepers]

Ausgezeichnet!

[volkssturm]

Jan 10, 2013 11:42:08 GMT -5 jeeperscreepers said:

Ausgezeichnet!

Gesundheit! ;D

[ersatzjack2]

That build looks very difficult and extremely one of a kind. It is gorgeous.

[jimmiroquai]

Update:

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
paint

[HornetWSO]

Really nice work!

[stuka]

nice but you may have to settle for a shorter barrel, not sure if there is 600 exact barrel other then that, it looks pretty fantastic

[jimmiroquai]

Thanks! I've installed 650mm and even a 700mm barrel before. Madbull has a 650mm and i've had custom barrels made by Edgi for my springer bolties before. What i'm having trouble finding is a non-active breaking mosfet..

[2nd Bat]

Spectacular build! So radical in terms of required adaptations and fabriction requirements. Great job.

[alienbones04]

Try Extreme Fire mosfets extreme-fire.com/ . I think his Simple MOSFET Units don't have active breaking. I've bought from him before too, and he is really easy to work with.

[jimmiroquai]

Thanks for the heads up! I was able to get a 3one MF-SMU which is based on the SW-SF open source. 3one was also one of the co-developers of the technology.

Update:
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!

[jimmiroquai]

Update:
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!

[2nd Bat]

An absolutely amazing build. You have become the new Schmitty and Big Ed of this Forum. outstanding work.

[Ersatzjack]

Alright, even though I don't do FJ because of the condom-like helmets, I'll give it a try. I'll take one. Do mine as a second version though and keep the price under $150. Just let me know where to send the money. That would seal the deal as to what 2nd Bat said about you and then you'd have my vote.

[jimmiroquai]

2nd Bat - I think i pretty much saved all their pics and bookmarked all their builds to learn all i could.

Ersatzjack - Hahaha! Well, now that i've built one i wouldn't be surprised if a chinasoft company announces one for pre-order soon. Just like what happened with the PPSh and Nagant.

[brownien]

Haha I feel ya! As soon as I got my BAR working, that first BAR was announced!