Gate Merf 3.2 not working correctly? F2000 semi-auto trigger not working

[RostokMcSpoons]

The spring does look a bit awry in that previous pic, but it looks ok to me now...

 

The sector gear has 2 or 3 shims underneath and 1 or 2 on the top it so yeah it doesn't seem that likely to have got it out of position.

 

Another reddit thread suggested going back to 7.4v, so I've just tried that.   Same thing.
So pretty sure there's a mechanical issue hidden in this thing somewhere!

 

When lunchtime arrives, and I can spend some quality time on this, I'll change over the contacts (which I don't expect to fix it) and then record some video. It'll give me a reason to try 'Slow Motion' mode on my phone camera for the first time ever

 

And if I get really, really, really stuck with this I'll try to put it all back to pre-MOSFET mode to see what happens then. 

 

Edited February 8, 2022 by RostokMcSpoons
(No need for splicing leads)

[RostokMcSpoons]

I bodged it back to pre-MOSFET wiring, and it still does it.  So the there's definitely something wrong with the trigger / COL assembly.

I've got some slo-mo video too... very instructional!  I can see the contact dolly moving up and breaking contact on the semi shots, and shuttling back and forward whilst flat on the burst/full shots.
I'll edit them down and upload them to YT shortly.

 

The interesting thing to note is for my first video I used a thicker piece of card to block the full-auto contacts, and that seemed to help it stay semi-auto.  When I recorded the second I just used electrical tape ... and eventually it does the burst/full. 

In any setup I find that once it's started to do it, it keeps on doing it.  Maybe something is sticking? I'm using silicon gear lube from AK2M4 sparingly on the moving parts - but perhaps it's too viscous?  Should I get some silicon spray in there to thin it down?

 

Edit: Decided the one video was enough: the first couple of shots go on semi correctly, it's all downhill from there...
 

 

Epic slo-mo sounds

 

Edit2: Ah sod it, I bought a replacement Rocket trigger unit and COL from @ak2m4 ... let's see if those will help at all.

Edited February 8, 2022 by RostokMcSpoons

[Adolf Hamster]

hmm, that's very definitely the col failing to lift the trolley.

 

wonder is the col worn? i know i said i didn't think it had earlier but i'm starting to doubt myself on that front. looks like it's in constant engagement, usually when you fire in auto it's lifted out of engagement to stop it wearing out as quickly.

 

other thing might be worth trying, but if you remove the auto contacts (as in physically remove them, not just isolate the wiring) and see if the extra clearance to pull the trigger back lets it trip properly?

[RostokMcSpoons]

The COL shouldn't be worn, the gun was new at Xmas, it's had a less than a couple of thousand BBs through it.
I have taken it all apart a few times though, and as I'm still "low on the foothills of Experience Mountain", I may have buggered it up somewhere along the line.  The fact it does work quite often before deciding it'd rather crap over everything is odd.  A bit of heat in the system makes it go wrong?  Maybe a tiny bit of expansion makes a 0.01mm difference somewhere and that's enough to b0rk it.
 
However, I've now seen enough other people complaining about similar issues with their F2K's (though mostly G&G which is very differently built) that maybe it's something that can just easily occur.

Hopefully the Rocket after-market parts will get it back on track, but I will try your suggestion tonight in the meantime.

[ak2m4]

@RostokMcSpoons posting it out this afternoon for you Ross, hopefully it works out.  Fingers crossed.

[Lozart]

If the new COL doesn't fix it, you could always try one of these: https://www.srairsoft.com/shop/f2000-m-trigger-gen-4

[RostokMcSpoons]

32 minutes ago, Lozart said:

If the new COL doesn't fix it, you could always try one of these: https://www.srairsoft.com/shop/f2000-m-trigger-gen-4

I saw that!  But...
Compatible only with G&G F2000’s without an ETU (pre-2019)

I'm not sure if that means 'only G&G' or really 'Only V3s without an ETU'.  
Given the G&G doesn't use a standard v3 gearbox, I'd have to ask them first.

 

33 minutes ago, ak2m4 said:

@RostokMcSpoons posting it out this afternoon for you Ross, hopefully it works out.  Fingers crossed.

Cheers    It'll be great to have my pew-pew pew, or pew-pew-pew on demand

Edited February 8, 2022 by RostokMcSpoons

[Adolf Hamster]

10 minutes ago, RostokMcSpoons said:

The COL shouldn't be worn, the gun was new at Xmas, it's had a less than a couple of thousand BBs through it.

 

that was my initial feeling, but the issue is that whereas in a normal gun the COL gets lifted free when used in auto that's not happening. although i've had plenty of v3 boxes firing a lot of rounds in semi auto to suggest they shouldn't wear out that quickly.

 

11 minutes ago, RostokMcSpoons said:

I have taken it all apart a few times though, and as I'm still "low on the foothills of Experience Mountain", I may have buggered it up somewhere along the line.  The fact it does work quite often before deciding it'd rather crap over everything is odd.  A bit of heat in the system makes it go wrong?  Maybe a tiny bit of expansion makes a 0.01mm difference somewhere and that's enough to b0rk it.

 

the thing i'm thinking is it's essentially half-pulling the trigger in normal use, compared to how it'd be in its normal ak role which is what the trigger/trolley/col was originally designed around.

 

13 minutes ago, RostokMcSpoons said:

However, I've now seen enough other people complaining about similar issues with their F2K's (though mostly G&G which is very differently built) that maybe it's something that can just easily occur.

 

i must admit, i'm getting a lot of deja vu here. col's wearing out quicker than you'd expect (granted on the g&g it's as much due to the weird leverage it's being put through) and being just a bit finnicky on semi.

 

17 minutes ago, RostokMcSpoons said:

Hopefully the Rocket after-market parts will get it back on track, but I will try your suggestion tonight in the meantime.

 

fingers crossed, if not there are still some cards left to play.

 

15 minutes ago, Lozart said:

If the new COL doesn't fix it, you could always try one of these: https://www.srairsoft.com/shop/f2000-m-trigger-gen-4

 

is an interesting solution, but it's for the g&g non mosfet version, although granted i wish it had been a thing when i was going through this

[RostokMcSpoons]

I've looked again at the manual for the Merf. 
I think if in the worst case I can't fix this, I change it to SEMI/BURST...  and then tweak the burst timer down to its minimum, and set the RoF reduction to its maximum and so if/when it goes wrong it fires only a one - or at worst two - shots and I can then get away with using it at my site  
It'll be an interesting experiment for tonight anyway!
 

[RostokMcSpoons]

2 hours ago, Adolf Hamster said:

other thing might be worth trying, but if you remove the auto contacts (as in physically remove them, not just isolate the wiring) and see if the extra clearance to pull the trigger back lets it trip properly?

 

Just took the gearbox apart again, moved one of the thicker shims on the sector gear from the bottom to the top, in the hope it would engage better with the COL.

And tried your thing of removing the trigger contacts.

 

As per usual, it worked fine on the first couple of shots, where I was squeezing the trigger gently, but as soon as I got slightly medieval on its ass and tried a more realistic trigger pull, "rat-a-tat-a-tat"

 

I'm going to re-set the wiring to use the MOSFET again, to try my cunning plan, and then it's down to those alternative parts.   Confidence is not very high

Edited February 8, 2022 by RostokMcSpoons

[Adolf Hamster]

12 minutes ago, RostokMcSpoons said:

As per usual, it worked fine on the first couple of shots, where I was squeezing the trigger gently, but as soon as I got slightly medieval on its ass and tried a more realistic trigger pull, "rat-a-tat-a-tat"

 

hmm, i was expecting the opposite- no dice unless you operate the trigger "in a soldierly fashion"

 

13 minutes ago, RostokMcSpoons said:

I'm going to re-set the wiring to use the MOSFET again, to try my cunning plan, and then it's down to those alternative parts.   Confidence is not very high

 

we haven't quite exhausted all the options, although the final option i'm certain will work it's not particularly appealing.

[RostokMcSpoons]

My cunning plan of programming the 'fet has resulted in a gun which mostly fires semi, but throws in a double-tap every four or five shots.
I expect I could get away with that, if I had to. 

But let's face it: the trigger action is bad enough with F2000's (and maybe bullpups in general) that you don't want to spend the whole game yanking away on the damned thing!

Plus I upgraded this gun to enjoy some high RoF antics (not full wanker-mode, obvs)

I must say I'm disappointed that a Cyma-built gun has turned out to be quite this fragile. 

Or perhaps my upgrade attempts have been a bit too ham-fisted. 

 

Edit:
Is there any chance the cam on the bottom of the sector gear could be the problem?  Should I buy a new gear too?

 

Edited February 8, 2022 by RostokMcSpoons

[Adolf Hamster]

19 minutes ago, RostokMcSpoons said:

My cunning plan of programming the 'fet has resulted in a gun which mostly fires semi, but throws in a double-tap every four or five shots.
I expect I could get away with that, if I had to. 

But let's face it: the trigger action is bad enough with F2000's (and maybe bullpups in general) that you don't want to spend the whole game yanking away on the damned thing!

Plus I upgraded this gun to enjoy some high RoF antics (not full wanker-mode, obvs)

 

don't blame ye, 90% of the firing i did with mine was in bursts outdoors, admittedly i lean towards semi in other guns, where the trigger isn't made by black and decker.....

 

20 minutes ago, RostokMcSpoons said:

I must say I'm disappointed that a Cyma-built gun has turned out to be quite this fragile. 

Or perhaps my upgrade attempts have been a bit too ham-fisted. 

 

it's one of the issues with the more obscure platforms is getting weird niggles like this, if it's any consolation the original g&g was every bit as bad but throw in lack of available spares for the trigger/col and lacking the end-game option.

 

21 minutes ago, RostokMcSpoons said:

Is there any chance the cam on the bottom of the sector gear could be the problem?  Should I buy a new gear too?

 

unlikely, out of the 2 the col is the thing that'll wear. don't think i've ever seen a sector cam actually wear out (as opposed to the default shape not matching a given col for a given box)

[Iceni]

Sorry been at work

Yeah definitely the COL/Dolly interaction that's failing. Glad it's not the Mosfet.

I'd replace the unit for standard V3 parts. The SHS/RA parts should be fine. But to be sure I'd do the COL and front contacts. That way you rule out wear, and warping on the COL as well. 

If I had the time I'd say pop over at the weekend and I'd fit it all for you, but we are in the final week before the British retail consortium audit at work, and panic mode in the engineering management is kicking in.

Edited February 8, 2022 by Iceni

[RostokMcSpoons]

That's a very generous offer Iceni, but hopefully I'll be able to jam all the parts in and make it work.

I've got three different hammers, how could it possibly fail?

 

 

I rather wish it was the MOSFET, that'd just be a warranty replacement, or swapping for a Perun, or even just reverting to the old wiring, rather than this mystery box stuff!

Oh, I've got a replacement COL on order too.

 

 

Edited February 8, 2022 by RostokMcSpoons

[RostokMcSpoons]

Oh damnit

 

I've just put in the new trigger unit, cut-off lever, bushings, adjusted the shims appropriately, and used my new nozzle.

My 'cunning plan' of super-short burst + lowered RoF still got me good single shot performance, in fact it's better than before as I didn't get any double-taps.  Then I reset to default semi/auto and got the bad news.  It now fires full auto all the time, rather than occasionally doing the semi-auto successfully.

I'm not ruling out a mistake on my part, but I double-checked the fitting and wiring before test firing.

 

I did notice the new trigger unit is differently sized to the original, so maybe I try the shuttle/dolly thing with the old trunnion and vice-versa to see if that changes anything.

Or swap the COL back, as that seemed to move only a small amount when engaged by the sector gear... so perhaps that's the issue.

 

Anyway, one good piece of news for me is that I managed to strip the gearbox, fit the new parts, and get it back together and firing in the space of an hour.   Thinking back to the first time I took a gearbox apart and then spent ~7 hours trying to put it back together, I have come quite a long way!

 

[Adolf Hamster]

14 minutes ago, RostokMcSpoons said:

Oh damnit

 

I've just put in the new trigger unit, cut-off lever, bushings, adjusted the shims appropriately, and used my new nozzle.

My 'cunning plan' of super-short burst + lowered RoF still got me good single shot performance, in fact it's better than before as I didn't get any double-taps.  Then I reset to default semi/auto and got the bad news.  It now fires full auto all the time, rather than occasionally doing the semi-auto successfully.

I'm not ruling out a mistake on my part, but I double-checked the fitting and wiring before test firing.

 

I did notice the new trigger unit is differently sized to the original, so maybe I try the shuttle/dolly thing with the old trunnion and vice-versa to see if that changes anything.

Or swap the COL back, as that seemed to move only a small amount when engaged by the sector gear... so perhaps that's the issue.

 

that's a pretty common issue with a non-matched col. part of the whole "compatible-ish" nature of airsoft. sometimes it's a case of try a bunch until you find one that works nice and why a well stocked box o' bits is handy.

 

did the original look particularly worn?

 

17 minutes ago, RostokMcSpoons said:

Anyway, one good piece of news for me is that I managed to strip the gearbox, fit the new parts, and get it back together and firing in the space of an hour.   Thinking back to the first time I took a gearbox apart and then spent ~7 hours trying to put it back together, I have come quite a long way!

 

yeah it's a steep curve but does get easier.

[RostokMcSpoons]

The original COL looks pristine. 
Now I have a Rocket COL + Rocket trigger unit not working properly together, guess we have to blame that on the gearbox shell... or the sector gear.
I will swap the original back in to see if works differently with the Rocket trigger unit.

Next thing will be a new gear set.

[Adolf Hamster]

Aye try the original col with the new trigger parts, no wear on the trolley? Im thinking maybe if the ledge the col engages with has managed to wear/get damage.

 

Gears shouldnt be the issue, although maybe worth comparing the cam to the original gears to be sure, although i'd be surprised.

[Iceni]

I did mention before about reversing the return spring. Perhaps you didn't quite understand what I meant by that, so I've done you a diagram.

My aps aug prefers the second way with the loop at the top, the JG likes it the other way round. The only thing to watch out for is the loop at the other end might look like it's close to the edge, But hopefully your shells are close enough that it can't jump off.

It might be worth just giving it a try before you put more money into it.

 

Edited February 9, 2022 by Iceni

[RostokMcSpoons]

Well blimey, I've only just read this thread, but earlier I stripped it all down and put in the old COL (it looks absolutely identical to the new part) and actually did try putting the spring in both ways!   Maybe I unconsciously absorbed your suggestion from previous posts, or maybe I forgot how it's supposed to go in 😏

 

Anyway, now I've got it back together the nozzle movement and the trigger actuation actually feels a little smoother than before.   Maybe something else wasn't quite right, or maybe the spring orientation really does make a difference... I can't tell.

 

Unfortunately my wife decided to go to sleep early so I can't test fire it.  Will do that first thing tomorrow! 

 

Edited February 10, 2022 by RostokMcSpoons

[Iceni]

7 minutes ago, RostokMcSpoons said:

Anyway, now I've got it back together the nozzle movement and the trigger actuation actually feels a little smoother than before.   Maybe something else wasn't quite right. It maybe the spring orientation does make a difference 

Yeah give it a go and see where you end up with it. I know on my APS I built it backwards and it was refusing to reset,  It would break, but then wouldn't shoot again unless you mashed the trigger a little. I'd have to strip the guns to check, but I wouldn't be surprised if the springs in both guns were bent differently.

Edited February 9, 2022 by Iceni

[RostokMcSpoons]

It didn't work, still the same as the previous test.

 

 

Am I going to have to buy some bigger hammers at this point?

 

 

Or perhaps do some sort of shimming of the underside of the trolley, so the COL moves it more when it hits?

Edited February 10, 2022 by RostokMcSpoons

[RostokMcSpoons]

Pics for your delectation...

 

 

Apologies for the cat hairs making an appearance, they're everywhere thanks to The Beast

 

Edit:  Gate got back to me again. They're suggesting I glue something on to the COL to make it raise the trolley higher.

 

That's a high-wear location, do you you think a piece of metal shim super-glued there will hold?  I suppose there's only one way to find out...

Edited February 10, 2022 by RostokMcSpoons

[Adolf Hamster]

10 hours ago, Iceni said:

I did mention before about reversing the return spring. Perhaps you didn't quite understand what I meant by that, so I've done you a diagram.

 

didn't think about that one.

 

i normally do a mid-way of having option 1 with the loop going under the second peg on the trolley or at least whichever method has the spring sitting straightest.

 

28 minutes ago, RostokMcSpoons said:

Pics for your delectation...

 

your right that the COL doesn't look significantly worn, the gears definitely not worn either.

 

not really seeing anything jumping out to eye, perhaps the col edge could be closer to the sector gear but again if that's the original col and gears then that's where it's supposed to be, but then we are talking airsoft levels of precision.

 

you could try pulling the trigger pack, have just the sector and col in and rotate it to see what kind of range of motion it has.

 

31 minutes ago, RostokMcSpoons said:

Edit:  Gate got back to me again. They're suggesting I glue something on to the COL to make it raise the trolley higher.

 

yeah that's the gap i'm thinking about.

 

if it were me i'd rather be checking different col's until finding one that was naturally a bit higher in that regard, main downside is getting access to a bunch of different col's.

 

when i did it would go to the local shop, tech there didn't mind me having a rummage through and chucking him a couple of £ for whatever random part i'd found to do the job.