Airsoft Ohio Forums

Airsoft Ohio Forums (http://www.airsoftohio.com/forums/index.php)
-   Electric Guns (AEG) (http://www.airsoftohio.com/forums/forumdisplay.php?f=23)
-   -   What Fuse to Use? (http://www.airsoftohio.com/forums/showthread.php?t=22911)

Blackbeard 05-24-2009 12:29 AM

What Fuse to Use?
 
I came across an interesting problem and wanted to see if anyone else has experience/input on the subject. My G&P M16A1 (with successfully attached m203 and heat guard) shoots 25 rounds per second with a 9.6v battery. The maximum discharge rate of the battery is 35 amps (as it says on the battery), and as many of you know, the stock fuse is only 15 amps.

So my gun randomly stopped firing the other day, and after checking the battery, I immediately opened the fusebox, sure enough, it was blown. I put a new fuse in the gun and it was firing great, again, but the the new fuse (also 15 amp) blew . . . again. So I went to buy more fuses (only had one extra), and I bought a pack of 15 amp fuses, as well as a pack with fuses that go up to 30 amps.

As I sat there with my friend (who is an electrical engineering major, soon to graduate) I was explaining the problem, and he laughed. It was ridiculously obvious, and did cross my mind, that the discharge rate of the battery will continue to blow the fuse, until I get a fuse that is equal to or above (he recommended at least 40 amp) the discharge rate of my battery.

Does this sound right? Is it safe to replace the stock fuse with one of a higher tolerance (I believe that would be the correct term), or is the stock fuse 15 amps for a reason (to protect the motor from a pre-determined level of acceptable stress?). Or, as I've seen in the past, is there some undue stress being put on my gun (motor/gearbox related) that could be causing the fuse to blow? Just wondering if I'm potentially destroying my gun/ or if it's destroying itself. Input is both welcomed and appreciated, thanks!

Warlock 05-24-2009 01:43 AM

I don't use a fuse, neither do alot of players I know. But if feel you must use one go with 20 amp slow burning fuse, the fuse inside is a lot thicker. That doesn't work just go up to 30.

Curious about the setup, its not very easy to get 25 rps with a 9.6, without killing fps. The chance of going over 30ish amps is hard without some kind of electrical short or the unforgiving systema magnum motor.
________
Body Science

Darkstar 05-24-2009 11:32 AM

Never use anything more than a 20Amp fuse. Don't use fast blow or time delay fuses. Use the medium/slow burn fuses. They can be found at any auto parts store. You can get 5 packs for about $2 dollars. Auto parts stores always carry the fuses you need so you usually don't need to worry about that which type.

I typically use 20Amp 32Volt fuses, though voltage isn't really revelant. But you don't want to go above 20Amps. The reason for this is that airsoft guns, even highly upgraded ones, rarely pull much more than 15Amps. If your gun is consistently pulling more than 15 Amps, then there's a problem somewhere. Your battery, which is capable of supplying up to 35 Amps, doesn't push the voltage. The motor is really what draws current from the battery when you close the switch (pull the trigger), so making sure your motor is working properly and your gearbox is working smoothly is very important. You can use a 100Amp battery in your gun, but your gun is going to draw the Amps it needs.

For example, if your gearbox gets jammed, the motor can't turn, and therefore is requiring more Amps to turn itself. Since it can't turn, it's essentially creating a short circuit, causing the motor to pull infinite Amps, thus blowing your fuse. Also, when your battery is drained and voltage drops, the motor is pulling more Amps to try to keep the voltage high, and this can cause your fuse to blow too. The vast majority of fuse blows are caused by a low battery and users that are not familiar with electricity or why and how fuses flow.

Good luck!

Blackbeard 05-24-2009 02:39 PM

Warlock, the gun is just a stock G&P M16A1 with an m120 high speed motor . The only upgrade so far has been a systema hop up unit and bucking (which added 20 fps, I chronoed before and after). Adding a 6.01 edGI barrel too (got from Kurt at Amped Airsoft!!!), which I'm afraid will put me over 400 fps. I love G&P, but nobody seems to say much about them on here. The motor and gearbox both sound smooth, cycling and everything sounds perfectly normal. I put a 30 amp fuse in it for now, but maybe I'll go with a 20 amp slow burning like you said Darkstar.

shmartin 03-22-2016 03:51 PM

Did you ever find out what the problem was because it sounds similar to what I am dealing with now.

RotaryProphet 03-22-2016 05:05 PM

Ignore the crap he said about the battery being overrated for the fuse -- That's just plain wrong. The gun only draws the power it needs, no matter the max discharge rate.

If your gun is blowing fuses, it means something is wrong in the gearbox -- It may need grease, it may be shimmed too tightly, or something could be wrong with the motor. Is the motor hot during firing? Does it blow the fuse very quickly, or just randomly? Is your rate of fire dropping during fire? How does the rate of fire compare to when it was newer? Those questions might help you narrow down the issue.

shmartin 03-23-2016 12:04 PM

Quote:

Originally Posted by RotaryProphet (Post 444522)
Ignore the crap he said about the battery being overrated for the fuse -- That's just plain wrong. The gun only draws the power it needs, no matter the max discharge rate.

If your gun is blowing fuses, it means something is wrong in the gearbox -- It may need grease, it may be shimmed too tightly, or something could be wrong with the motor. Is the motor hot during firing? Does it blow the fuse very quickly, or just randomly? Is your rate of fire dropping during fire? How does the rate of fire compare to when it was newer? Those questions might help you narrow down the issue.

Tearing down my gun I cant figure out whats wrong with it. My gun was blowing multiple fuses at an event a few days ago. So we tried hot wiring without a fuse worked a few seconds then stopped. Nothing appears damaged with my trigger contacts. I tested them with a multimeter as far as I know without tearing the gearbox apart. The motor also still works when I directly connected it to a battery. I have an idea its my motor which is the same one the original poster has a G&P M120 High Speed. I upgraded the spring in my gun a bit prior to all this happening with a M120 spring. It worked perfect for a few games until now. Before the gun stated blowing fusses I noticed my motor running slower then usual before it quit all together. From what information I have gather so far. Even though the motor is rated to pull a M120 people do not recommend it. So I think I damaged the motor. I am just looking around trying to find if anyone has run into a similar problem with a G&P M120 High Speed Motor.


All times are GMT -5. The time now is 02:48 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Copyright 2005 - 2009 Airsoft Ohio