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tNostalgia

Advice Welcome: 40 RPS AUG Build

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So I'm looking to pump my RPS up to around 40 RPS on my JG AUG and achieve around 320-350 FPS and I was wondering whether these parts I have selected can reach that goal. Below are my proposed parts upgrades.

 

-SHS High Torque motor

-SHS 12:1 High-speed gears

-Guarder SP100 Spring

-Homemade 3034 MOSFET

-Deans connector mods for battery and gearbox

-11.1V LiPo

 

I'm on a relatively low budget so suggestions will be much appreaciated

Also, I would like to ask if these components would stand up to the challenge and will not break under such stress.

 

Thank you

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Eh.... might as well dsg if you want 40. And that will cost a lot. Single sector at 40 isn't pretty. You can reliably get 35 with single sector and that's with an 11.1, 13:1, 16 tpa shs/rocket motor, and whatever 300-350fps spring. You'll want an shs lightweight piston with the steel rack too. Plus, you'll need to trim of teeth at the front to avoid pme. 

 

There's a lot of things that can go wrong. If you've never cracked open a gearbox before, forget it. Just settle for same as i've said but with a 7.4v, or maybe 16:1 to be safe. If you go with the 7.4v option, all you will need is:

  • that green shs/rocket motor £30 ish
  • 13:1 £15
  • 7.4v battery £12 each-ish? Or maybe you already have some

And with a few teeth trimmings on the plastic piston, that should be around 25rps on max charge which is still very fast. The plastic piston should last at that speed. You also don't necessarily need a new spring. Most springs are good enough. If the fps is too high then just cut one coil at a time. Deans connectors aren't that necessary either if you are hardcore budgeting (assuming you don't have any, and a soldering iron too).

 

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1 hour ago, tNostalgia said:

So I'm looking to pump my RPS up to around 40 RPS on my JG AUG and achieve around 320-350 FPS and I was wondering whether these parts I have selected can reach that goal. Below are my proposed parts upgrades.

 

-SHS High Torque motor

-SHS 12:1 High-speed gears

-Guarder SP100 Spring

-Homemade 3034 MOSFET

-Deans connector mods for battery and gearbox

-11.1V LiPo

 

I'm on a relatively low budget so suggestions will be much appreaciated

Also, I would like to ask if these components would stand up to the challenge and will not break under such stress.

 

Thank you

Short answer: nope.

Like @AK47frizzle mentioned you need better parts selection, and nothing will create a stable 40rps without DSG or significant gearbox modification.

The problems you will face with the AUG.

Inner barrel length. It's 509mm on a standard AUG. You need all of the cylinder to get the most out of that. You can use a shorter barrel length to overcome this, but you may run into alignment issues as the AUG inner barrel is free-floating in an aluminium guide sleeve inside the outer barrel. I've used 300mm barrels without an issue but that's not saying your's will be fine. For a DSG setup, you are going to be looking at 200mm and that may be a problem. You can not shim an AUG barrel, It fucks up the airseal.

Homemade 3034 fet will work but it will have to be an AB type. A stock non-braking fet will not work at all for fast RPS. For the investment of about £25 you can get a toggleable AB fet, with built-in fuse and lipo protection (gate nanohard). A Warfet ect with gearbox control would be more ideal, but you may find you are space limited.

More budget-friendly Fets like the Xcoretech XET304u and Acemos are generally under £10 They don't have AB but will give contact protection if you are staying on the 11.1v route. I've built my own units in the past, but nothing beats a pre-made unit that doesn't have resistors wrapped round a pair of fets, and fet legs constantly been wobbled about, Eventually, the homemade unit will succumb to fatigue and the legs will just drop off.
https://www.ak2m4.co.uk/internal-parts/mosfets/acemos

The gearbox components don't fail because of poor build quality in most high ROF builds. They fail because the piston isn't given enough time to complete its travel, So the sector gear grabs the piston early and rams it much further back in the shells. That causes the sector and piston to smash. The smash will strip gears, pistons and crack gearbox shells. It's a catastrophic failure and can cost a lot of money to put right. 

With that in mind, the ideal RPS is 20-25. And you can do that with a 7.4v lipo if you are building the gearbox from scratch.

It is very very easy to mess up an AUG with the incorrect upgrades. Even the air nozzle is not an easy swap as there are variances in overall length between the various manufacturers.

If it is your own gun, and it's shooting well, Leave it alone. The JG blue on an M100 running 11.1v must be hitting almost 20 rps anyway.
 

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@Iceni @AK47frizzle 

Thanks a lot for the advice, I've learned quite a bit from the info you guys have given me :)

 

With a £70 budget, I'm not extreme budgeting, so the parts you guys mentioned are in range.

 

I'll go with that ACETECH mosfet Iceni mentioned since I still think 11.1V LiPo is the path I want to take.

Soldering Deans connections and Mosfet wiring should be fine since I'm an Electronics student with my own soldering iron and good knowledge of understanding circuit diagrams etc. so no worries.

 

I need to figure how to trim some teeth off a steel rack on an SHS piston (File it down??). If you have any specific mentions for a piston please link it. Otherwise, my gun is screwed which both of you explicitly pointed out (Thanks, I would of really broken my AEG if you guys haven't said)

 

A reasonable aim for RPS would be 25-30 with the 340 FPS I have now so I'll just use a 13:1 and SHS HT and keep the stock spring.

 

Generally, (I think) JG make pretty durable stuff so I'll probably keep most of the parts stock. (Maybe an SHS spring guide and Air nozzle for the air seal)

In terms of barrel length, I don't really know what to do. When I eventually upgrade or change the barrel (Madbull maybe?) I don't know if I should go for that 300mm or a 509mm length one. That's just something I have to deal with another time.

 

Otherwise thank you guys so much for your advice and if you see something that's wrong in my current plan just correct me.

 

Once again, thank you very much!

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8 hours ago, tNostalgia said:

I need to figure how to trim some teeth off a steel rack on an SHS piston (File it down??). If you have any specific mentions for a piston please link it. Otherwise, my gun is screwed which both of you explicitly pointed out (Thanks, I would of really broken my AEG if you guys haven't said)


I don't file the piston at all. Take the teeth from the Sector gear on the pickup side. A bastard file will work, but a rotary tool is much faster.


Any decent steel racked piston will be fine.

The modification to the piston is filing down a tooth height-wise. It's done to make the gearbox a little smoother on the pickup of the piston, but I generally don't bother, I just shim the piston to the sector if needed.

 

8 hours ago, tNostalgia said:

Generally, (I think) JG make pretty durable stuff so I'll probably keep most of the parts stock. (Maybe an SHS spring guide and Air nozzle for the air seal)


JG are pretty durable, but the parts most keep are the gears, gearbox shells, Piston, Piston head, Cylinder head, Cylinder. The air nozzle and spring guide are more often than not replaced you just have to be careful with the air nozzle.

Spring guide for V3 the best one is the solid brass Deepfire one. As it adds mass to the gearbox that helps with gearbox noise. A steel one  (£8)would also be fine and is considerably cheaper.

https://www.ak2m4.co.uk/internal-parts/spring-guides/ra-spring-guide-stainless-steel-v3

 

8 hours ago, tNostalgia said:

In terms of barrel length, I don't really know what to do. When I eventually upgrade or change the barrel (Madbull maybe?) I don't know if I should go for that 300mm or a 509mm length one.


If you are reducing the Stroke of the piston by removing teeth from the pickup side of the sector then you need a shorter barrel. The ZCI 6.03 300mm (£18) is the best budget option. Forget about the madbull they generally don't last very long, if they perform at all (I've never had any luck with them).
https://www.ak2m4.co.uk/internal-parts/inner-barrels/zci-inner-barrel-300mm

 

If you do the barrel then do the hop rubber as well, The Prometheus purple  (£9.50) is good all-round rubber. You want it to be as soft as possible.
https://www.ak2m4.co.uk/internal-parts/hop-up-buckings-nubs/laylax-prometheus-bucking-purple


Mosfet £10,
Barrel £18
Hop rubber £9.50
Spring guide £8
Gears £14 (ZCI re-enforced)
Grease £2.50
Motor £28.50
Piston £10
Bushings £5
Shims £5
Tappet plate £5

Total is £115.50 so overbudget but it covers everything.

https://www.ak2m4.co.uk/internal-parts/motors-parts/ra-high-torque-motor-short
https://www.ak2m4.co.uk/internal-parts/grease/super-lube-lubrication-grease-5ml-syringe
https://www.ak2m4.co.uk/internal-parts/gears/zci-gear-set-13-1-reinforced

 

You will have to measure the bushings to get the correct size, and perhaps a tappet plate depending on wear. 

Re-buiding gearboxes isn't cheap. If it's done right and to the 25rps rule then the gearbox will last years so it can be money well spent.

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14 hours ago, Iceni said:


If it is your own gun, and it's shooting well, Leave it alone. The JG blue on an M100 running 11.1v must be hitting almost 20 rps anyway.
 

 

^^^ THIS 200% ^^^

 

You can't really push a long barrel full stroke m100 UK spec gun much past 25rps

without work & shorter barrel, Short Stroking blah x 3

 

if you think 30~40rps is your goal then please make vid...

 

Image result for thi is gonna be good gif

 

Many of us know this coz we've smashed stuff to shit taking the piss

 

Twenties is plenty, even then as you approach 20's it starts to overspin

even double fire if your cut off lever is worn...

Oh I'll replace it then...

Do you know that the V3 silver JG COL is different to say the black SHS COL you might buy...

 

Image result for sitting duck airsoft forum jg cut off lever

 

That is just one example of stuff not just "dropping in"

and what joy this so called TM Compatible BS is at times

 

So attention to detail and crap blah x 3

 

and even then, after all the most careful planning in the world

you can still blow shit up by taking the piss way too much

 

keep it real, 20's is plenty and you don't need to go nutz buying loads of go faster bits

(not just yet, you can get near it on a JG blue 22tpa on 11.1v - gotta be near 20 as mentioned)

 

Personally use it as until it plays up then replace bits as needed

but up you

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