G&P Sentry Gearbox Lockup

DaveTheSpic

Hey Guys,

The gearbox on my Sentry fires on semi auto for a while, it will do the same with auto too. After a while it won't fire on either and the gearbox seems to lockup.

Any ideas on what could be done?

thermo

DaveTheSpic wrote: »

Hey Guys,

The gearbox on my Sentry fires on semi auto for a while, it will do the same with auto too. After a while it won't fire on either and the gearbox seems to lockup.

Any ideas on what could be done?

what battery are you using?

DaveTheSpic

thermo wrote: »

what battery are you using?

I'm using an ASG 7.4v 1300mAh 15C Li-ion.

thermo

have you tried it with a higher output battery the one your using may not have enough "juice".

THE MINDER

Is the trigger itself locked in position?If so its likely you have a mechanical fault in the trigger system(G+P) are notorious for locking in semi but tipping it into auto usually resets the system okay.Another common fault is broken gear shafts-:mad:sometimes the gun will fire and sometimes wont-try thermos suggestion but unless your battery is foooked IMO it should be strong enough to run that set up-so try another to rule this out.Failing that if your technical knowledge is not great you really need to get it opened.They use silicone wire in these that cuts easily causing shorts that may be intermittent and as far as I am aware there is no fuse in that model.Are you still under warranty? Get it looked at and sorted,Sorry I cant be of more help than that,
Dave.:)

Southern Dandy

I fixed the spics sentry what are brothers for eh!! It was a problem with the trigger assembly it just wasnt sitting in right, whoever changed out the spring just didnt give a toss and slapped it all together and not to mention selling my bruv a g&p 7.4 lipo that was dead (hence other post) and measured 2volts when i put my meter across it.

Anywho i just stripped the gearbox and cleaned the lot, regreased the gears cleaned the trigger contacts and put it back together and tis firing like a dream now. To be honest it was under warranty but with the way the aeg came in the post, stock tube was completely loose, a different dust cover was fitted and doesnt close at all and the fact they couldnt change a spring and reassemble it properly so i said id do it for him!! soz but im venting and fairly annoyed with them.

Cheers anyway minder appreciate the help.

THE MINDER

Gud for you buddy-sorted thats the main thing.Just a point to note on the dust cover is that G+P make them that way.The catch on the dustcover is made to the same spec/size as the real steel version so as to immitate realism(The cover would be open when firing) and for this reason it is impossible to close Some like it that way and some dont-its just a G+P thing.If it bothers you though you can always remove the dust cover and grind of the catch(Until Flat) Give it a lick of kyrlon paint and when replacing flip the spring around the other way-can be a little fiddley but the flap will remain closed all the time(Held up by the spring)If going down this road remove the inner dummy bolt cover to make it easier to adjust the hop:)

Southern Dandy

THE MINDER wrote: »

Gud for you buddy-sorted thats the main thing.Just a point to note on the dust cover is that G+P make them that way. sThe catch on the dustcover is made to the same spec/size as the real steel version so as to immitate realism(The cover would be open when firing) and for this reason iot is impossible to close Some like it and some dont-its just a G+P thing.If it bothers though you can always remove the dust cover and grind of the catch(Until Flat) Give it a lick of kyrlon paint and when replacing flip the spring around the other way-can be a little fiddley but the flap will remain closed all the time(Held up by the spring)If going down this road remove the inner dummy bolt cover to make it easier to adjust the hop:)

Ah right didnt know that now, see you can close it on my kwa when you use the charging handle so was basing it on that, learn something new everyday ha!

floppyjoe

had the same kind of issues with my G&P gear box. also had to dissasemble the gearbox to fix the mess the person who downgraded it made.

An awful lot of retailers just dont take the time or care to properly downgrade a spring.

mine spring was cut (badly) not even a new spring and the gears were not timed properly. shooting was a real mess out of the box.

Leftyflip

...And voided your warranty, presumably this was a recent purchase?
Seriously though, if you were unhappy with the performance of the AEG, you should have brought it back.

floppyjoe

Not a resent purchase and I wouldn't call 30 days a warranty..

Skirmished once in 30 days and problems got worse over time. There's a reason retailers only give 1 or 2 month warranties as they know they'll give trouble over time and by the time you figure it out it's too late.

Leftyflip

floppyjoe wrote: »

Not a resent purchase and I wouldn't call 30 days a warranty..

Skirmished once in 30 days and problems got worse over time. There's a reason retailers only give 1 or 2 month warranties as they know they'll give trouble over time and by the time you figure it out it's too late.

Fair enough so.
Not going to get into a debate - but usually, in my experience, the first 30 days is usually when a problem arises.
Can you do me a favour and explain how the gears weren't timed properly? No other reason than curiosity

floppyjoe

Leftyflip wrote: »

Fair enough so.
Not going to get into a debate - but usually, in my experience, the first 30 days is usually when a problem arises.
Can you do me a favour and explain how the gears weren't timed properly? No other reason than curiosity

The sector gear was too far back causing the piston and tappet to be out of time with each other.

Leftyflip

floppyjoe wrote: »

The sector gear was too far back causing the piston and tappet to be out of time with each other.

**Personal Opinion**
There's no "timing" when it comes to the gears, they're either in the right place or not. If the sector gear is in the wrong place, the gearbox will not close properly, not cycle or strip the piston. The sector only engages the piston and tappet plate in one way. They go in one way. It's possible however, that when you opened the gearbox - the piston was already engaged and drawn back slightly, then when the shell was opened slightly, the piston released with the sector gear being in a weird orientation. But as I said - you can't time the gears.

The battery you were using is a low discharge one, G&P don't run that great on 8.4v batteries, never mind a low discharge battery like that (less power than an 8.4v), which I believe to be the original cause of the problem.

My final question is - how do you know it wasn't downgraded at the source and done badly? I was talking to a friend today and there seems to be a real "restaurant attitude" with people, where if they're not happy with something they don't go to the manager or the retailer and make them aware of the problem - they just go off in a huff and moan.

**End Personal Opinion**

But hey, I could be wrong and not know anything at all...

floppyjoe

Leftyflip wrote: »

No other reason than curiosity

sure you are... Beware of the troll...

And you got one thing right in that last statement anyway

Leftyflip

floppyjoe wrote: »

sure you are... Beware of the troll...

And you got one thing right in that last statement anyway

Yes, I'm clearly trolling by adding my opinion.
Ah it's not worth it... Thanks for the insult though mate
Take care now

DeBurca

Gear timing is a myth, it does not exist

The “Timing” is set by the maker of the sector gear and it is the relationship between the spigot that pulls on the tappet plate and the gears on the sector gear that engage with the piston and cannot be “timed” or “changed” or “set” for that matter

Yes it is a whole lot easier to reassemble a gearbox if this spigot is positioned at approx the 2 o’clock position as it exerts no pressure on the tappet plate or sector gear and helps keeps everything in line making it easier to position and close the other half of the gearbox

THE MINDER

Gear timing in and of itself is not a myth otherwise we woud'nt be dicussing it in the first place:) However to say that the GEARS NEED TO BE TIMED with the sector gear positioned at around the 1 - 2 'o clock position in relation to the tappet plate FOR THE GEARBOX TO FUNCTION IS HOWEVER A MYTH! For those who disagree think about it logically-once that trigger has been pulled it is highly unlikely that even if the sector gear started in this position that it will stop in the same spot,even the anti reversal latch/bevel gear ridges will most likely prevent it happening-Jeez half the time the piston ends up in the half pulled back position(Which is why we try release it with a single shot after play) and that might require the sector gear to be at someing like 7 or 8 o'clock. DOES the gun stop working- NO-so there is the myth out the window LOL:D
Its MY opinion however that this set up is not only advantagous in setting up your mech box(for reasons already outlined) but it can be advantagous if it can be maintained through the use of AB fets,ASCU's, Raptors and the like simply because on single the gearbox cycle is completed fully each time the trigger is pulled giving a crisper and more consistent shot.Again this is only an opinion and each to there own:)