Fuse blew

[Handsome Pete]

I recently upgraded my G&G Gr 25. I put a spring in etc and after much stress managed to get the gear box back together. Before i put the top half/barrel section back on the gun i gave it a test fire. The first shot i got a bright blue flash from the fuse and nothing else. Took out the fuse it says 15 amp. So do i need a higher amp fuse or the same or does it matter? Ive been to homebase, B&Q and and electricians shop but the max they sell is 13 amp. Please help, i think this is the only thing preventing me from using my new beasty. cheers.

[Xaccers]

You need to find out why the fuse blew really.

[MDK_Marshal]

13 Amp fuse is fine, but as xaccers said, a new one won't do anything usefull untill you find out why it blew (IE, what the major problem with the gun is) and fix it.

[sadman]

I recently upgraded my G&G Gr 25. I put a spring in etc and after much stress managed to get the gear box back together. Before i put the top half/barrel section back on the gun i gave it a test fire. The first shot i got a bright blue flash from the fuse and nothing else. Took out the fuse it says 15 amp. So do i need a higher amp fuse or the same or does it matter? Ive been to homebase, B&Q and and electricians shop but the max they sell is 13 amp. Please help, i think this is the only thing preventing me from using my new beasty. cheers.

<{POST_SNAPBACK}>

 

If you have an automotive shop near you they will most likely have them as the fuses in AEG's are common in cars.

[Handsome Pete]

ok. Well i was told in another thread that after upgrading the spring it is common for the fuse to blow but praps not. lmk, cheers.

[MDK_Marshal]

Erm.

 

The only way that upgrading a spring would cause a fuse to blow that fast and spectacularly would be if you'd done something realy rather wrong in the gearbox, or if you'd put in a spring that could produce something like 3,000 fps.

 

If the gearbox is upgraded properly, then to the best of my knowledge you can run at 20rps and 500fps with a 15A fuse... (just an example, but you get my point )

[tank423]

can pop a 20A car fuse in the post to you if you want??

[The Gopher]

can pop a 20A car fuse in the post to you if you want??

<{POST_SNAPBACK}>

 

Depends on the kinds. Mini fuses and regular snap in fuses are not the same as tubular fuses used in your replica.

 

Don't be stupid. Put the same capacity fuse back in, after you figure out what went wrong. You probably have the anti-reversal latch on backwards or it's jammed somewhere.

 

Bypassing the fuse and other lowlife moves are not "right".

[eel one [COE]]

I really don't know why all the forums that are kept english, refuses to acknowledge that running an AEG without a fuse causes no problems as long as you don't keep the trigger pulled if your gun jams, makes noises or in other ways stops functioning as usual. In Denmark almost all mechanics removes fuses from the system. But we also runs M120 springs at 25 rounds/sec as a standard. So as long as you takes care in making a proper installation of new parts you will be G2G with out the fuse. If anything you should gain 1-1.5 rounds/sec. by stripping the old wires and installing 1.5mm^2 wires instead (that is if you already runs around 25 rounds/sec. other wise the gain will be lower if you run at a lower ROF).

 

Any way, no mater if you do or do not have a fuse in the system, you need to get your box checked. Usually these things are caused by a poor shim job resulting in to much tension which drains more amps from your battery that your fuse can take. If this is not the case, take a look at the wires to the motor. If it is reversed the motor will pull the gears in the wrong direction, which is impossible due to the reversal prevention latch. Also pay attention to the bushings, If just one of them are not installed right, the gears will not run like they are supposed to, again causing excessive tension in the system.

 

Last, please make a list of what you have done in the gearbox. What parts has been changed besides the spring (what spring is it). If you provide details, it will be a lot easier for us to help you to resolve your problem.

[Xaccers]

If you know how a fuse works then you'll know why it's important.

A jammed gearbox can cause over 30A to be drawn even with a short trigger pull.

Without a fuse, you will do damage to the circuit, which includes the motor and battery.

The damage may not be much, but it's still damage.

There's a reason why batteries come with discharge ratings.

 

One of the reasons why people have had problems with lipols is where they've run with a battery that isn't able to cope with the current flow, causing the battery to go bang.

 

I've had long term skirmishers come up to me with a jammed gun and a red hot pistol grip where they've tried to clear the jam by going to full auto.

People in general do not understand electricity, and so don't know that when their gun jams the last thing they should do is pull the trigger.

 

How often have you heard someone say "oh my battery is running down so my fps is dropping" or ask "will a 9.6v battery increase my fps?" which just goes to show how little some people understand about their guns.

[mikkelhenriksen]

Xaccers> Yes the fuse is an importen part if you dont know what your doing with your gun and don't have a common sense broken things.

 

I have used softguns since ´92, been a mechanic since '94 and for 4 years been in shop selling, repairing and upgrading softguns. I have not been using a fuse since ~´94-95 I have to this day not seen a motor crash due to over heating caursted by broken or misplaced parts in a gearboks. The old systema motors died because they overheated, but they were ###### anyway.

 

The wires and swich may die, but still that take quit an effort.

 

As the eel said: it is common in Denmark to remove the fuse as one of the first things.

 

Handsome Pete> Find someone who knows how a box works and let him/her check it and if nessesery repair it.

[eel one [COE]]

When you make a fuse removal, you also makes sure that the person who owns the gun understands how he should react in situations like those you describe.

 

You already short your electrical system each time you pull the trigger. Which is why semi shooting kills switches and motors much faster that full auto shooting. So if you claim that you damages your battery by making a short pull with a jammed box (the pull where you find out that some thing is wrong) you also damages the battery doing ordinary shooting. Remember how the fuses in AEGs works, they don't blow instantly by having a higher amp current running through them, that they are rated to (here I have to apologize for my lack of english vocabulary, but I believe the correct technical term are inert fuses). So they only blow when you drain a sustained higher current from the battery, than the fuses are rated for. It is normal for an standard AEG to peak with 25-30 amps doing start up, even with a 15 or 20 amp fuse in the system and it will run with out any problems. This is also why it is important to chose the right type of fuse if you run with them in your gun.

 

People running with LiPO batterys should have a safety circuit in the battery to prevent them from exploding, otherwise they are asking for problems as we do drain a lot of amps doing start up of the gears, specially when the main spring are resting with tension due the over spin of the gears and the reversal prevention latch not allowing the gears to spin back to relieve the tension.

 

That people are long term airsofters doesn't mean that they have been instructed in the proper response to a jammed gear box.

 

I rarely hear some one asking if higher voltage will give them higher ROF. But I do believe that it has some thing to do with the average age of players in Denmark compared to other places. Here your can't legally buy an airsoft gun if you are under 18 years old and the majority of players in the danish community are 21-22 years old (according to polls on the danish community board). Higher age also mean a better understanding of mechanical and electrical systems (these thing are taught in the school system but are voluntary).

 

After I read this topic, I started a poll on the danish board www.airsoftzone.dk/community (sorry danish only, but it is the largest national board) on weather or not people have fuses in their upgraded AEG. The result are at this moment, that the majority (94%) runs without fuses in upgraded guns.

[Tom Andrews]

After I read this topic, I started a poll on the danish board www.airsoftzone.dk/community (sorry danish only, but it is the largest national board) on weather or not people have fuses in their upgraded AEG. The result are at this moment is that the majority (94%) runs without fuses in upgraded guns.

<{POST_SNAPBACK}>

 

 

If you have an upgraded gun or have upgraded your own gun, there is a better chance that you understand not to keep pulling the trigger if it doesn't work.

But as the O/P has shown, its easy the first few times you open your gearbox to do something wrong. Without the fuse, he may have been tempted to continue pulling the trigger, resulting in possible damage.

 

It the reason why some cars are fitted with rev limiters, - to protect our property from ourselves!

[Xaccers]

I said batteries have discharge rates listed for a reason.

The burst rate of my battery is something like 90A, with a continuous discharge of 63A

As you can see, well above what a fully functional AEG will pull per single shot.

Many NiMH batteries have lower discharge rates, and some HK retailers have been selling lipols with discharge rates under 15A!

As long as the current doesn't go over the discharge rates that your battery can handle, you'll be fine.

Start drawing more through a jam and you'll start doing damage.

Worse is if you get a short, you'll go way over what your battery can handle and unlike lipols which swell and eventually burst into flames, a NiMH or NiCd is likely to explode.

 

AEG fuses are slow blow, meaning they, like batteries, have two ratings, the continuous one (the one stamped on it such as 15A) and the burst rating which is how high the current can go for a short period of time without the fuse wire blowing.

 

Fire a series of shots off on semi and you can watch the fuse glow and pop, because you aren't giving it time to cool back down again.

Likewise with the wires, and the motor and more importantly the battery.

Now, remove that fuse and fire off a series of shots on semi, you can go on and on and on until your pistol grip gets too hot to hold.

People don't realise that if their wires and motor are getting that hot, the battery is also heating up.

 

This is a UK forum with UK members, most of whom I would summize are under 18 and it has been posted many times "do bigger batteries increase fps?" through lack of understanding.

As such, I feel it is irresponsible to suggest running without a fuse when you consider that a large proportion of forum members will not understand the consiquenses and dangers.

[eel one [COE]]

I agree with Tom Andrews, my protest are a result of the common opinion on english languaged boards and remarks like

Bypassing the fuse and other lowlife moves are not "right".

 

I find it some what offending each time I'm told more or less that I don't know what I'm talking about and should ###### of because we do things differently and has experience in making our things work the way that we say that it will work.

 

I don't want people to do things my way as I know that there are as many ways to do things as there are mechanics. If people want to go with fuses... well... by all mean do use them. But please do take in to consideration that others have and share knowledge about other solutions. I offer my knowledge so others have more options to chose from.

 

I do also believe that I gave a list of things that potentially could be wrong with the gun since it blew a fuse like an old school camera flash. I also mentioned that one should take care in installing things the right way. I take longer in working on guns than other mechanics as I double checks every thing before final assembly. I understand how these guns work and takes pride in passing on my knowledge to others who shows an interest in it. I have been in this sport since around '95, and I have started to feel that it might not be so many years before I quit. I have found the danish community to be of grate assistance and would like to pass on the knowledge I have.

 

Edit:

@ Xaccers: No, I do not find it irresponsible to suggest running AEGs without a fuse. I have stated that caution and increased attention is needed if one chooses to remove the fuse. We are already getting more technical that most airsofters can understand. But those who want to upgrade there own guns deserve to have options. Being an airsoft mechanic are not for all airsofters. It takes skills, and a short cut to achieving those skills, are by getting inputs from pleases like the internet. I only regret not understanding japanese and cantonese, as there are some very innovative people in that part of the world. Getting the same results as those people, will take me many hours in the work shop. Hours I could have saved by reading how to do things and picking out those bits that would be suited for my needs.

[Handsome Pete]

The Gopher: Im not being 'stupid'. I have very little knowedge in this department and so am attempting to learn by my successes and mistakes. Technical discussion, infact most of arnies is here for airsofters to converse and discuss news, gear tactics equipment and also HELPout if must.

 

Besides that alot has been posted wow. The Gr 25 is semi auto only so i can't have given it a burst and also, the first shot i fired the fuse went so i applied the safety and since put this thread up. Looks like i'll have to open it up again. Hopefully a team mate can take a look at it. Ill keep those whom are interested posted. cheers.

[Xaccers]

Open her up, remove the piston, cylinder/head/tappet plate, then screw her back together.

Put your finger in through the side of the gearbox and spin the gears, they should spin freely.

If they don't, you need to re-shim.

 

If they do spin freely, then check to make sure none of the wiring is pinched or bare causing a short.

Make sure the anti-reversal latch is in place and engaging with the bevel gear properly, on my mate's CA25 it's a pain in the backside to get it to stay in place.

[The Gopher]

I didn't mean to say this

 

"

Bypassing the fuse and other lowlife moves are not "right".

"

 

to imply everybody is stupid here. I run the fuse, because i believe it was put there for a good reason. Anybody is free to remove it and anything else they wish to their replicas. That is perfectly fine with me. And I didn't say anybody was stupid, I said "don't be stupid". That doesn't imply anybody.

 

Among other low life moves, like putting 14.4v batteries in a stock gun, chopping barrels off without deburring the end, running FA until the grip gets hot, ahm...putting hopup on max then cleaning out the barrel, among other things...sometimes its ignorance or you just didn't know any better, other times its stupidity...

 

Mr. Andrews referenced rev limiters in cars — those are there for a reason — though they can be pushed with proper upgrades — but stock, the valvetrain and (especially with big in-line six engines and bigger) the crank can only take so much punishment...

 

I mean, let's not get all offended and personal. this is an airsoft (a game) on the internet (a virtual, but real, but not really real ) enviroment with some people. let's not get all fussy.

 

I just got out my MP5. Measured 8.78v (8.4v cheap battery ) before the fuse and 8.78 after. It's not like it drops it a volt or something. while we're at it let's go ahead and pull all of our car fuses and put straight jumpers in :D

 

EDIT: let's not compare larger diameter wires unfused with top grade connectors versus a fused standard "okay" wires. Compare "larger diameter wires with same connectors" versus "larger diameter wires with same connectors, fused".

[The Gopher]

...

 

So does anyone have any tested replicas where stock wires with no fuse were compared to stock wires with a fuse? FPS and RPS difference?

[eel one [COE]]

First of all, the electronics in an AEG do NOT effect the FPS in any way!

 

secondly:

 

EDIT: let's not compare larger diameter wires unfused with top grade connectors versus a fused standard "okay" wires. Compare "larger diameter wires with same connectors" versus "larger diameter wires with same connectors, fused".

 

OK, I just made a quick audio measurement of ROF with and without a fuse. Same weapon, same setup, same battery. First run was with a fuse, second round was without a fuse A direct increase in ROF by 3.187% only by fuse removal. Not much, but it is measurable. People running high speed setups around 1800 rounds/min (30 rounds/sec.) will benefit more by fuse removal that I do on the setup I measured here.

 

With fuse: 1107.7 rounds/min (18.4616 rounds/sec.)

 

Without fuse: 1142.9 rounds/min (19.0483 rounds/sec.)

 

A direct increase in ROF by 3.187% only by fuse removal. Not much, but it is measurable. People running high speed setups around 1800 rounds/min (30 rounds/sec.) will benefit more by fuse removal that I do on the setup I measured here. At the 1500 rounds/min. (25 rounds/sec.) the gun runs with a charged battery I usually get an increase around 4% or in absolute numbers, around 1 round/sec.

 

(and now to recharge my battery it has been running for 3 weekends in a row without a recharge, so it's about time)

 

In case some one want to know: It was a 20A fuse and a spring 96% above forum limits.