G&G SIG 552 ** Mod for fitting an 8.4v mini nun-chuck in handguard.

[Schlyder]

I recently aquired a G&G Sig 552.
I did not want to use a Lipo battery though.... as apparently that is all that fits in itside the handguard in it's stock state.
So I had to figure out a way to get an 8.4v mini nun-chuck or Crane battery pack to fit the hand guard. After giving everything a good eye-balling
and a little thought, I came up with a way to make it work.

Step 1

- dremel out the two "bulkheads" in the lower half of the handguard...
(the front one and the next one back.)
Trim these as tight as you can to the wall and floor of the lower half of the handguard.




Step 2

- remove the upper... remove the hop-up and inner barrel.... tape back wires out of the way...
- dremel (grind) some off some of the outer barrel, on the bottom 6 O'clock of the outer barrel. You need to remove 1/16th - 1/8 of an inch... BE CAREFUL not to go too deep or you will end up with a slotted bottom of the outer barrel. Go slowly and take a little off at a time, and try fitting the battery as you go.





Step 3

- cut wires from built in Tamiya plug and install Deans connector.




Step 4

- Install battery.... attach handguard. Slide upper receiver onto lower receiver and re-insert body pin. You now have an 8.4v mini nun-chuk installed in your G&G Sig 552.





I slipped a piece of black craft paper in the top handguard under the battery
so all is hidden from view through the holes.

Mod is a 100% complete success.

Here she is with her bigger sister.

[TaroBear]

Suffers from ICS battery issues, I see. Huh.

[Schlyder]

Yeah, I don't know WTF G&G were thinking after the fail ICS had, that and maybe try to install a battery when you are prototyping it.
But the mod works. And it was easy to do.

[LoricTheMad]

I'm guessing by the velcro strap around the hand guard, that your bipod flops around then?

[Schlyder]

Nope, the velcro is there so when going through bush that branches don't get in behind and snag them, and pull them out. Also when using a sling.... the sling slides down in between the handguard and bipod legs and gets caught up. The velcro stops the sling form doing that.
The bipod legs click into place, and stay in place just fine without the velcro. Exact same as the real steel. I use the velcro on my Swiss Arms Black Special too.

[TaroBear]

I'm going to see if I can apply this mode to the ICS after the string of games this month. Hopefully then I won't have my AEG sounding like a sports bike on the LiPo.

[Margi]

That's a great tutorial. Since I'm done with NiMh and NiCd batteries, I was browsing through LiPo batteries on some RC sites and whenever I spotted one that caught my attention, I would take the measurements and reproduced them on some cardboard box, cut it to dimensions, fold it and attach it with some tape and voilÃ*! This way, I can put it into the handguard and see if it will fit and unfortunately, the smallest one would not.

This guide however might come in handy. I'm not wanting to get an airsoft branded LiPo but that specific model that Kong Power is doing looks like the most appropriate.

[Schlyder]

Thanks,
Yes the Kong Lipo battery is what Redwolf says fits it.
If you are getting a G&G SIG 552, try it with a NiMh (externally) first and see if you like the ROF.
I found with the 8.4v minichuk that the ROF was plenty fast. And a Lipo may produce too high a ROF. ( 7.4v Lipo is like 9.6v NiMh)
I find the 8.4v mini battery a perfect combination of good ROF, ease of use, length of charge, and cost effectiveness. Cost effective because NiMh are cheap, and I don't need to get another charger and low volt alarm etc.

[etd]

I think I'll stick to my 10.8v in the tm/jg sigs thanks. I've been saving up for an ics for the past month and my goal was to get a sig of every type... Really happy I found this thread.

[Schlyder]

I said the G&G SIG 552 ... different parts, motors, etc.
If you need the 10.8v with your JG/TM set up to get a good ROF, it's what you need. But it would be way too insane a ROF in the G&G 552. 8.4v is plenty.

[Margi]

Do you get a satisfying trigger risponse with the 8.4? I forgot to precise that this is also a must have on my AEGs but adding a MOSFET and Deans connectors should get the job done right?

[Schlyder]

yeah trigger response is good. I believe that bypassing the built in largeTamiya plug and using Deans helps to get better response with the 8.4v mini.

On my G&G SIG 550, I am going to bypass that same plug as well, with Deans plugs. I use 8.4v and 9.6 with it, and the 9.6v mini stick in the 550 is about the same ROF with the 8.4v in the 552. (The motor in the 550 is the 007 Magnum )
Also, I think they may have a new designed motor ( with a bit more speed.) in the new models.

[Margi]

Excellent. I have not disassembled my SIG yet but would you know if there is any way to remove the built in Tamiya connector? It will allow for a little more space actually.

I believe you have to take it apart the same fashion as the TM SIG only by looking on the magazine well. Also, there are those two screws that hold the stock in place where there would normally by a pin which that allows to separate the upper receiver from the lower.

[Schlyder]

There two small screws holding it in place. You don't need to take apart the reciever to get at the screws.
And, yes..... all you need to do to separate the upper and lower is remove the front pin. Then slide the upper receiver forward, and away from the mechbox. That's it.

[Margi]

Ok. I've watched one more time a video from RA-Tech on YouTube, the one where they test the ICS SIG 552 and it looks like it has about the same battery space as the in the G&G. If that's the case, a tri-panel LiPo would also fit in there. Have you had the chance to test that?