G&G TR4-18 burning smell

[chrisbirley]

Hi,

Hope someone can provide some advice please. I purchased my first RIF today - a very nice G&G TR4-18, it feels very nice, and has some nice features to hopefully mean i wont need to do much to the gun in the future.

i was dissuaded against going for a lipo, and got a 7 cell 8.4V 2200maH NIMH instead, little bit of a squeeze into the stock, but it just means i cant use the stock fully retracted.

the assistant in the store recommended that when i get home i should put a couple of hi caps through the un to bed the Hop Up in properly, so i duly followed his recommendation. the battery was already charged from the shop. i probably got through about 600 rounds before the gun stopped. it wasnt a slow down in the speed of the BBs leaving the barrel . the stock was very hot and i also noticed a strong electrical burning smell. upon removing the battery (it was fine, hot but no visible damage), i noticed that the mosfet's heat shrink seemed to have worn. given that this is a brand new gun, do you have any suggestions, or is this normal?

i've already contacted the retailer and will case up on Monday, but just wondered whether anyone else had experienced similar or whether it is nothing to worry about.

Chris

 

[GiantKiwi]

I think you might need to take it back, that sounds very much like their is a bare wire causing a short internally, the cable around the mosfet definitely shouldn't be worn on a new gun, especially with the thickness of the heatshrink G&G have adopted as of late.

 

[BrightCandle]

We have been getting reports that some of the Gen 3 G&G top tech guns mosfets have been burning out. So far those reports were limited to 11.1 lipo's but there is clearly a problem with the mosfets. My guess is that this has probably failed. Return to the shop for a repair, they will presumably work out precisely what went wrong and fix it.

 

[chrisbirley]

many thanks for the responses, i had seen some of the talk about issues when using 11.1 lipos but didn't think it would have affected me considering i not using lipos. i will be contacting the retailer on Monday, and shall post as to how things go.

 

[chrisbirley]

so, i spoke to the retailer, and they took the gun back to repair it - paid for postage and everything. sent it back to me after a couple of days, (the mosfet had burnt out). didnt have a chance to test the gun until a few days later. i started test firing it again, and noticed that the gear box was locking - that was me due to not fully pulling the trigger (will probably look at getting a finer trigger, but that will come later) and then noticed that for some strange reason the gun would start to fire fully auto when the selector switch was set to semi. this didnt seem right, but have seen it before with some rental guns so flicked to full, and then back to semi, but still had the same issue. i also noticed that when running it as full on semi it started to drain incredibly quickly. the gun went back to the retailer needless to say, was told that the problem was potentially the trigger or gearbox, or the mosfet. picked the gun up on Saturday and was informed that it was the mosfet, to which i replied again??

apparantly the mosfet in G&Gs doesnt like quick semi play - thats a shame as that is kind of how i play (at least at the moment). so onto my real question.....

the gun has a year warranty and the shop have told me that they are happy to send me mosfets to allow e to replace it instead of me sending the gun back to them every so often - do i just do this for the year that it is under warranty?

or

do i look at removing the mosfet

or

do i look at replacing the mosfet with a better one - i have read that AB mosfet can burn out with high semi play due to how they work, so do you have any recommendations for a semi only (hardly ever use full) player with a mosfet?

thanks

 

[Lozart]

so, i spoke to the retailer, and they took the gun back to repair it - paid for postage and everything. sent it back to me after a couple of days, (the mosfet had burnt out). didnt have a chance to test the gun until a few days later. i started test firing it again, and noticed that the gear box was locking - that was me due to not fully pulling the trigger (will probably look at getting a finer trigger, but that will come later) and then noticed that for some strange reason the gun would start to fire fully auto when the selector switch was set to semi. this didnt seem right, but have seen it before with some rental guns so flicked to full, and then back to semi, but still had the same issue. i also noticed that when running it as full on semi it started to drain incredibly quickly. the gun went back to the retailer needless to say, was told that the problem was potentially the trigger or gearbox, or the mosfet. picked the gun up on Saturday and was informed that it was the mosfet, to which i replied again??

apparantly the mosfet in G&Gs doesnt like quick semi play - thats a shame as that is kind of how i play (at least at the moment). so onto my real question.....

the gun has a year warranty and the shop have told me that they are happy to send me mosfets to allow e to replace it instead of me sending the gun back to them every so often - do i just do this for the year that it is under warranty?

or

do i look at removing the mosfet

or

do i look at replacing the mosfet with a better one - i have read that AB mosfet can burn out with high semi play due to how they work, so do you have any recommendations for a semi only (hardly ever use full) player with a mosfet?

thanks

If the G&G mosfet os going to give you that much grief I'd get rid and install a better aftermarket one. I have a similar play style and I use a GATE Nano AB (newer versions available now - check their website). Not had any issues with it running on 7.4v LiPo.

 

[BrightCandle]

I personally have been pretty disappointed with my T418. Having had quite a few gearbox lockups myself, feeding issues and a really inconsistent hop up unit (its about 3 peoples widths at 30m, awful accuracy with hop on, excellent with it off) I kind of think the T4-18 gen 3 is an utter lemon of a gun. Its far less reliable and accurate than my combat machine. I suspect my mosfet will probably show issues if I get in a heavy gun fight at some point and I will probably send it back. Honestly I think the T4-18 gen 3 is a terrible gun, an unreliable piece of junk.

 

[chrisbirley]

Hi Loz

i like the look of that one - is yours hardwired in, or are you using it Plug and Play style?

thanks

 

[Lozart]

Hi Loz

i like the look of that one - is yours hardwired in, or are you using it Plug and Play style?

thanks

Hardwired. Plug and play doesn't protect the trigger contacts or give you the Active Braking benefits.

 

[Baz JJ]

Ive got the Gen 3 and use it with a 7.4V LiPO.

Have had it just over a year but haven't had any problems with mine yet.

 

[chrisbirley]

thanks for the input BrightCandle - as of yet i havent managed to skirmish with the gun - but that is all due to me as havent been able to due to work commitments. i will be this coming Sunday and hoping that all is good. whilst i have it under warranty i shall be utilising that as much as possible, and will use the first opportunity to test the hop and distance etc; but if it gets all too much then i will probably look at replacing the mosfet with a better one - like the one that Loz has suggested.

 

[Lozart]

Good friend of mine has one and he swears by it.

 

[chrisbirley]

so another update. i didnt touch the gun after having got it back, i had its first skirmish coming up the following Sunday, and new that if i found another issue i wouldnt have had it fixed in time, so figured i would wait.

got to he site nice and early, sorted myself out and took the gun to the range to chrono it, and the first shot since the gun had come back from the retailer was a real struggle, it sounded almost as though the battery was flat and was struggling to spin up the motor, similar to what had happened the previous time. it was also firing full auto when set to semi. it chrono'd under the site limit and i started using it for the first game with much trepidation. i was right to do so couldnt fire i nsemi at all, and probably got about 12bbs fired before the gun locked up and couldnt do anything - not happy.

wondering whether it was my battery causing the issue i tried a mates and that still had issues, and he tried my battery in his gun and that was fine.

i emailed the retailer again and they have taken the gun back to look into it further. i also emailed G&G to get their take on this - their initial response was that it was the battery causing the problem and said that my discharge rate of the battery was too high - i informed them that i was using a battery recommended by the retailer.

got a phone call form the retailer today asking me what the problem was as they were testing the gun and had no issues at all - when i explained things to them, they didnt see how the type of battery could be the issue, and said they would look further into the gun.

the biggest worry i have is that yes i could get them to remove/ replace/ install a 3rd party mosfet but something is not right with the gun given that things seem to be blowing very very quickly.

i will see what they come back with in their further investigations and go from there - im very very close to using the sale of good act with the fact that ive had the gun for just over a month and havent been able to use it for its intended purpose, so please can i have a replacement, but will give them the benefit of the doubt for the time being

 

[Trojan]

Hi mate

Did you say you are using a 8.4?

I think people are over looking this. It is likely the culprit!

What is happening is the battery doesn't output enough volts to allow the G and G HT motor to power through a GB cycle properly.

Buy a 9.6 or an7.4 lipo. Also solder a better MOSFET.... AB ones are good but can also have negative impact... The simplest solution? Non AB FET. Cheap and can withstand really high volts

Basically pull the trigger properly and give the gun enough amps and there will be no problem.

 

[chrisbirley]

hi Trojan,

yeah, im running the retailer recommended 8.4V crane stock NiMH 2200mAh battery. im more than happy to move to a different battery, and would have been happy to have gone to Lipo, but was persuaded against it for a starter due to looking at them funny and going bang (ok slight exaggeration).

i have heard of issues with the G&G mosfet - mainly with people using 11.1V Lipos, but figured i would look at doing the replacement as and when it failed after the warranty expired - was not anticipating it being quite so soon

thanks

 

[Trojan]

Yeah the lock ups is definetly due to the battery lacking sufficient power to go through the GB... Which is why the retailer confirmed it works properly but you didn't - they forgot to test multiple batteries. You should definetly tell them if the battery was the problem and that if it was they should test with different voltages.

Also mass manufactured mosfets such as the g n g do not under go good stress tests like private FETs or expensive FETs. Get a cheap MOSFET like the extreme fires or hamsterfets to actually have the benefit of a real MOSFET. Batch manufactured FETs are super awesome Quality, such as the btc spectres etc

 

[chrisbirley]

just to give you all an update, after having been in discussion with G&G and the retailer, it has been decided to give me a brand new replacement TR4-18. fingers crossed i have more luck with this one. i also have a new 9.9V life being delivered too to give it a bit of a boost.