Ngrs issue / stopped firing

[Enid_Puceflange]

Ok, so I upgraded the spring in my ngrs 416 a few months ago to eek out some more fps

And it’s been working flawlessly until this weekend. I haven’t upgraded anything else other than the hop rubbber
Running it on a Titan 7.4, it’s had probably 6k rounds through it since the spring change….

 

The issues seem to have started with the Ambi selector switch

I noticed that the right side (as you are looking down the replica) was out of sync with the left side, so removing the motor then pistol grip allowed me to align them again, and all was well.

This weekend saw that issue return, so I duly repeated that process and got on with my days play.

 

If I was shooting semi quickly, the gun would jam, a quick flick to full auto, then back to semi would sort it.

But this weekend saw that issue return, and flicking the selector did not resolve the problem, the gun did nothing.

I unplugged the battery, and back in again , and still nothing.

As it sits, it’s back to firing, but obviously something isn’t happy and I have upset the TM fairies that live inside!

 

Not being a competent aeg tech, I’m wondering where I should start to look?

 

Selector switch?

Selector plate?

The mechanism that cuts off power when mag is empty?

 

The gearbox all sounds ok, and no strange noises from the motor, no excessive heat from anywhere, and the battery isn’t getting warm.

 

I probably had put 2500 rounds through it on the weekend, and it started acting up at the end of the day

 

Could it just be low voltage from a drained battery (7.4 v 3000 mah Titan)

I checked it’s voltage on my charger when I got home and it showed 7.7v , it’s normally showing 8.4v when fully charged

 

Where should I start?

Edited April 22 by Enid_Puceflange

[Anonymoose]

While i can't help with the issue, what spring did you go for and what power did it give you?

[Enid_Puceflange]

Fitted an Eagle six m100

When it was first installed, it was shooting at 356 on a .2 (1.18j)

Its now settled down to 285 ish on a .28 at the weekend Chrono check. (1.06j)

Edited April 22 by Enid_Puceflange

[Anonymoose]

24 minutes ago, Enid_Puceflange said:

Fitted an Eagle six m100

When it was first installed, it was shooting at 356 on a .2 (1.18j)

Its now settled down to 285 ish on a .28 at the weekend Chrono check. (1.06j)

 

 

Hmm, i've ordered M90+s. Maybe i should change them to 95s or 100s. 🤔

[mightyjebus]

soooo....

 

7.7v was probably enough for the NGRS to play up, It's not so much the voltage but more the current that the battery can supply. Fixing the semi-auto-back to semi issue can be solved 2 ways. 1. fit a high torque motor and this will stop it happening around 90% of the time. 2. fit a leviathan Mosfet and it will go away for good.  

 

Sounds like the ambi gears are worn and allowing them to slip and get out of alignment. I can't remember if there is a screw holding the 2 parts together but if so a bit of thread lock will stop the screw working loose and allowing enough room for the selectors to slip. The gear teeth are pot metal so will wear eventually so maybe trying to source a replacement might be a good idea as it could take a while to find one. 

[Enid_Puceflange]

54 minutes ago, mightyjebus said:

soooo....

 

7.7v was probably enough for the NGRS to play up, It's not so much the voltage but more the current that the battery can supply. Fixing the semi-auto-back to semi issue can be solved 2 ways. 1. fit a high torque motor and this will stop it happening around 90% of the time. 2. fit a leviathan Mosfet and it will go away for good.  

 

Sounds like the ambi gears are worn and allowing them to slip and get out of alignment. I can't remember if there is a screw holding the 2 parts together but if so a bit of thread lock will stop the screw working loose and allowing enough room for the selectors to slip. The gear teeth are pot metal so will wear eventually so maybe trying to source a replacement might be a good idea as it could take a while to find one. 

Thanks for that

I’ll probably take it apart next week and have a look at things 🫣

Do you recon using a standard 7.4 LiPo and not the Titan would help matters?

Edited April 22 by Enid_Puceflange

[mightyjebus]

I don't think it matters too much which battery, just that it has enough juice for it to turn over the AEG. Titans are normally pretty good but I've seen a few go wrong in the past. Most 7.4v LIPO's usually show around 8v fully charged so not much difference.

[ak2m4]

@Enid_Puceflange not sure if you've fixed or not but if you can post the problem on the FB ngrs and Graeme from Tactical Geordies will help you out

[Enid_Puceflange]

Not had time to look at it yet

but thanks for the suggestion and will do 👍

[Enid_Puceflange]

So,

I had a look at this the other day, and possibly narrowed it down a bit.

The rif shoots sweet for about 20-30 rounds, then stops firing, I thought initially that it was a power/gearbox issue…..

But firing it , it’s acting like it is stopping firing on empty…

So I take the mag out, put it back in, and hit the “bolt release” and it fires away like nothing is wrong for another 20-30 shots

When I take the mag out, it’s feeding fine (a few beebs fall out of the hop unit)

and the rest of the mags beebs are still under pressure , ready to feed

Whilst I had the receivers split apart, I disassembled the hop unit to clean it and the rubber, could the rubber have moved causing an issue , when it was back together it fired like nothing is wrong issue, but I just feel that’s not sorted it.

 

Could I be experiencing some sort of “Midcap Syndrome”?
I doubt the mechanism that is lifted by the mags lever to activate the stop on empty function could be the cause of it, but that’s what the symptoms suggest 🤷🏻‍♂️

Edited Monday at 15:18 by Enid_Puceflange

[Hatchet]

If it looks like the stop on empty function then it might be worth checking anyway. That's got a small spring on it if memory serves and if it's not been put back together right (or even tightened up too much) perhaps the cutover is just being subject to the whims of vibration rather than functioning correctly.

[Enid_Puceflange]

2 hours ago, Hatchet said:

If it looks like the stop on empty function then it might be worth checking anyway. That's got a small spring on it if memory serves and if it's not been put back together right (or even tightened up too much) perhaps the cutover is just being subject to the whims of vibration rather than functioning correctly.

 

I’ll probably investigate that then

Its a pain in the proverbial to strip the replica down, as the battery wires thread in under and between the buffer tube and the castle nut 😣

[mightyjebus]

easy check is to hold the bolt release down and see if it happens. if it doesn't happen then there is a problem with the bolt release/spring/3 parts that are attached to the outside of the gearbox and the little spring that makes these parts move. It's also worth trying different mags as this can cause the issue as the little bolt release lever on the mag can sometimes play up and trip the stop feature.

[Enid_Puceflange]

12 hours ago, mightyjebus said:

easy check is to hold the bolt release down and see if it happens. 

I genuinely never thought to do that! 🤦🏻‍♂️

I’ll give that a bash 👍
That would certainly help narrow things down

Edited 19 hours ago by Enid_Puceflange