MP5SD Fusebox removal? why?

[Rabbit]

What are the dangers in doing this?

I've been looking at upgrading the battery in the SD make foregrip where the battery compartment is, but some of the batteries being sold state that the fusebox has to be removed. I figure its there for a reason in the first place.

The batteries that are being sold appear to be a double nunchuck battery for anything 9.6v and above 1500mah.

i plan to use cheapbatterypacks.com to attempt to make something up.

[m102404]

Go search though the site for "removing fuse" or "fuse removal".

It's been discussed several times and some of the top notch guys chimed in on the topic. Extremely good info. Different points of view and opinions too...but more than enough information for you to make your own decision.

[Rabbit]

CDN_Stalker i guess summed it up

"BTW, fuses only protect the wiring, nothing else. If a surge large enough to damage anything in the gun, it'd be the wiring that would disintegrate, not the parts. But in that case you'd have to have the trigger pulled for a while to make it happen. Even in extreme normal cases, the wiring would get hot to the touch, but still it'd take effort to damage the wire further than that. "

But is it as easy as snipping it out and just soldering the wires back together?

[m102404]

Essentially yes...but...

Depends on how nicely it's done...I've seen some horribly botched jobs of "soldering" and joining wires.

The cleanest thing to do is to run new wiring and connectors.

McGuyver, Kos-Mos and some others have some very good points to make as well.

Re batteries....why upgrade the battery?
1. Looking for more run-time?
Consider a 7.2v 2000mah lipo. A 9.6v mini won't give you much more run time vs. a 8.4v mini.

2. Higher Rate Of Fire/quicker trigger response?
9.6v batteries (vs. 8.4v) will do that but will put more wear and tear on your switch unit, especially if you shoot a lot of semi (there's less wear and tear on the switch shooting full auto).

Two different sides of a coin when looking to upgrade the battery.

[Rabbit]

I dont even know what to think. Wow. I think i need a smoke

What can i do to prevent internal damage from a 9.6v..can anything be replaced? I googled switch unit for an aeg but most of it referred to wiring

[Styrak]

The best question is, what are you looking to do?
Why do you need 9.6v?

[m102404]

Think of the switch as one of those manual throw switches (like the cartoon electric chair big lever switches).

Every time the switch block is just about to enter the contacts it "sparks"...where electricty will jump the connection just before it's made. And everytime the block is pulled out it'll "spark" again as the contacts separate. So with semi, it sparks twice per shot....100 shots on semi and it sparks 200 times. With full auto it sparks once at the beginning and once at the end...a 100 shot full auto string is 2 sparks.

As it sparks it burns/corrodes the little metal contact fins...which wear out so much it'll get to the point where it won't work at all any more.

To alleviate things you can:
1. Replace the switch periodically
2. Use lower voltage batteries
3. Use a MOSFET

Dummies explanation of MOSFETs (there's lots written elsewhere)...
- think of the MOSFET as two switches
- one switch needs just a tiny bit of power and uses very small voltages
- the other switch can "dump"/pass lots of power through it really quickly
- when the little switch circuit is closed the chip opens up the big switch...like using a little lever to open a big flood gate of a dam.
- the switch in the AEG controls the little switch and the motor is wired to the big switch...the MOSFET chip essentially separating the two
- since there's little voltage through the switch now...they'll basically last forever
- since power is being provided to the motor more efficiently it runs better/faster

How efficiently, fast, and how much power a MOSFET can pass is dependant on the chip used to make it.

***short answer since you seem to be paying attention and actually giving some thought to it ***
- if you can fit it, you can run the 9.6v mini in your SD without a fuse
- if your gun locks up, jams, sounds odd....STOP trying to use it right away and get it looked at/fixed
- with the 9.6v mini your switch will wear out faster than with a 8.4v...disassemble your gun once a season for cleaning/maintenance and check the switch...if it looks good, keep using it. If it looks black, burned, corroded...swap it out.

[Rabbit]

I like the idea of quicker trigger response and ROF is always pleasurable. I do shoot a lot of semi which is why that comment doesn't sit right

But im assuming mini's wont give you much run time comparing the 9.6 to 8.4 but the response time and rof are the only reasons i'd want a 9.6 over the 8.4

It almost sounds like the 8.4 is the mid way point between the lipo with high mah and the 9.6 with damage being caused in the long run.

Edit: Just read the last post.

While i was reading about the switch unit, MOSFETs were brought up into it. Reading your post it makes things extra clear now. Im not going to lie or try to pretend, getting into a MOSFET would be wayyy over my head right.

Its very interesting to know that this type of option excists. That post was actually a great read.

Thanks a million!

[m102404]

A 7.4v 2000mah lipo will act sort of like a large 8.4v battery....no crazy ROF goosing of the system, but decent staying power for lots of shots.

Also...less arcing = longer switch life

Don't be too thrown by MOSFETs...some are IC controlled with tons of features...others are not much more than a pinky nail sized chip with a couple of resistors soldered together. Depends on what features/functions you're looking for.

Best of luck

(If it was my own gun, I'd go with the 7.4v lipo that fit the space, keep the fuse because I wouldn't need to remove it to make space and just swap the switch if needed down the road)

[Styrak]

What kind of FPS setup are you running?
A 1500/1600mAh mini should give you a decent ROF. I run 1100mAh sticks in my CYMA AKS74U and it's shooting 380fps, and the rate of fire is still decent.

Are you not happy with an 8.4v? Have you even tried it?

[Rabbit]

Im judging this based on the stock UMG I had, I was running an intellect 8.4 1100 mah getting 245-265fps...

I've recently purchased a TM MP5SD6 and just want to be prepared to atleast hit over 300fps

[Styrak]

What do you mean? Do you mean you want to be able to upgrade to 300-400 fps and still have a good rate of fire and trigger response?
I'm not sure what you're saying.

[Rabbit]

Originally Posted by Styrak

What do you mean? Do you mean you want to be able to upgrade to 300-400 fps and still have a good rate of fire and trigger response?
I'm not sure what you're saying.

Lol i apologize, yes thats exactly what im saying.

I've read about how a 9.6v can increase ROF/Response moving up from an 8.4.

The expirience i've had with a stick 8.4v Intellect 1100mah in my UMG was giving a chrono'd speed of 245-265fps

I was hoping that by jumping to a 9.6v mini type in my MP5SD6 was going to bring me over 300fps. This is why i wanted to avoid the 8.4v (again, this is based on the expirience ive had with the 8.4v in my UMG)

But going with the 9.6v as explained would eventually lead to further problems which i'd like to avoid. So Im willing to settle for the 8.4v. Im just trying to get as much info as i can before heading over to cheapbatterypacks.com

[Styrak]

Uh, sounds like you think changing your battery will change your FPS.
This is a wrong assumption. The only thing that changes your FPS is your spring.

If that's not what you were thinking let me know.

[Rabbit]

Originally Posted by Styrak

Uh, sounds like you think changing your battery will change your FPS.
This is a wrong assumption. The only thing that changes your FPS is your spring.

If that's not what you were thinking let me know.

No..that IS what I was thinking.

However when I think about it, its almost common sense that the battery voltage would only affect the ROF/Response. I really dont know why I thought this.

I was told by fellow players that I needed a new spring for a better fps. I wanted to get a spring but looking this up on the forums let me know that just upgrading a spring can be damaging and that further parts would have to be upgraded as well to 'handle' the spring.

<-- Noob failsauce

I just can't remember what has to go along with the spring upgrade. I've seen some pictures, and i can't remember where, where the spring has kind of torn up the inside and how flakes of whatever can get into places they shouldn't.

I think I just really need to understand how the mechanism actually works and this should give me a better understanding of what to upgrade :banghead: