Mosfet confusion

[DanBow]

I've done a search but cant find the answer that I need. I've also searched youtube, which has done nothing to make the issue any clearer.

 

I have a rather lovely cyma Blue Mp5 ( you may have seen it here), using ASG LiPo 7.4v batteries. I've no intention of using anything other than these at the moment. I like it as it is. At the moment.

 

So, as I'm not going to be using 11.1v batteries, do I need to fit a mosfet? Would I gain anything from fitting one?

 

Desperately wanting to fettle but only if it's worth it.

 

 

 

 

[Colin Allen]

What do YOU want to achieve by fitting a mosfet?

[DanBow]

7 minutes ago, Colin Allen said:

What do YOU want to achieve by fitting a mosfet?

 

An increase in something but I'm not sure what. Or a more consistent something else but I don't know what. Maybe dancing girls throwing rose petals at my feet as my laser like BBs take out the enemy and lets me feed on their blood but i don't think a mosfet can help with that particular one!

 

Ultimately, I dont know! 🤷‍♂️

[Fatboy40]

I've a CYMA MP5K that's sat idle in a cupboard at the moment, bought used with three mags, but it's waiting until I can install a GATE Titan v3 into it (so we're talking controller / ETU rather than just a MOSFET). The plan is that I'll gain...

 

# Custom trigger sensitivity, the standard "pull" on the MP5K is shocking and goes on and on and on...

# I only ever want to use it on semi, so all selector settings will be semi only.

# With so little battery space I want a controller that will support brushless motors, so still using 7.4v I get a snappy trigger with one.

 

... and with starting a new job on Monday, that will make me around £160 a month better off, hopefully it'll happen soon 🤞

[concretesnail]

If you're notnsure what you want to gain then I'd consider doing nothing and sit tight.

If you do decide that you'd like to fiddle then I'd look at the perun ab++. Easy to fit very compact, lots of options which you can choose to use or not and they aren't expensive. 

 

[Adolf Hamster]

For a basic mosfet you're mostly going to gain elongated trigger contact life, ofc wether or not that has any meaningful impact compared to just replacing them when the time comes is up to you, usually the answer is no unless you have some weird trigger components that are a pain to source spares for.

 

More advanced mosfets, well i tend to lean towards there not being much point until you get to precocking mosfets, active braking for example tends to cause more problems than it solves unless its used in conjunction with precocking, and i've never felt burst modes to be particularly useful. But precocking is where you start to get real meaningful performance gains (ie "trigger response") even with the simpler timed systems like the ab++ and the warfet.

 

After that ofc its optical, and tbh, unless you really care that the first shot of semi after a burst of auto absolutely must be consistently precocked, or really want dat trigger sensitivity then you dont really need them.

[DanBow]

It looks like im going to do nothing, for at least a while but i will have a look at the Perun ab++. 👍

[Rogerborg]

I'd concur.  Anything short of an AB++ is largely pointless, and I include using 11.1V, given that trigger contacts are a £5 part.  The AB++ is a well featured unit, and easy to fit.

[Colin Allen]

3 hours ago, concretesnail said:

If you're notnsure what you want to gain then I'd consider doing nothing and sit tight.

If you do decide that you'd like to fiddle then I'd look at the perun ab++. Easy to fit very compact, lots of options which you can choose to use or not and they aren't expensive. 

 

Another vote here for the Perun AB++; they are easy to fit and provide a good range of features, especially pre-cocking.  However, the Perun Hybrid for V2 gearboxes is also excellent and easy to install.

2 hours ago, DanBow said:

It looks like im going to do nothing, for at least a while but i will have a look at the Perun ab++. 👍

I think you have made the right decision.

[Sewdhull]

There are 2 types of MOSFETs.

 

The type that prolong the life of your trigger contacts by doing the switching of the power to your motor and the type that add features to your gun, which also prolong contact lifespan.

 

The former should be fitted to all guns in my view as the contacts for Airsoft guns are not very good and are the same as when everyone used nimh batteries with lower current outputs. You will get more power to your motor and a way longer contact lifespan.

 

 

 

 

[Galvatron]

For what it's worth, I fitted a Perun MOSFET to my P90. My specific reason for doing so was wanting to improve the trigger response as most familiar with the standard TM P90 and its clones will tell you there is a big and inconsistent dead zone (especially in semi-auto) with the trigger bar and contacts on the gearbox. The Perun unit does away with all of that and replaces the cut-off lever with its own.

 

I can't stress enough how big a difference it has made as the trigger response is vastly superior and more consistent, with me no longer having a dead zone as a source of frustration.

[The_Lord_Poncho]

I've wired/soldered a simple cheap (£20ish from memory) ASG mosfet into a couple of my guns, just to protect the trigger contacts. I was hoping that i would notice an increase in trigger response, but I suspect that any improvement is somewhat imagined. I have a few guns that don't have mosfets in (including a Cyma MP5), that i have used on a 7.4 battery for a few years without any drama at all.

 

As an alternative to the Peruns recommended above, I recently popped a T238 mosfet (V2 1.9) from Aliexpress into a boneyard gearbox/gun that I fancied tinkering with. Cost of £27 including postage, a pretty simple operation, and works perfectly. Provides for a binary trigger, stops gearbox lock up+ overspin. To be honest, the main reason I fitted it was that a gearbox I bought had electrical issues. As the T238 eliminated the trigger contacts, and came with all the wiring etc, it was just as easy to pop that in, rather than re-wire and solder everything together to replace the standard electrics.

[MrTea]

On my MP5, before I was doing my own tech work, I had a tech fit the cheapest mosfet they had (Gate Pico SSR3 - £15) just so I could run 11.1v LiPo safely. It has exactly zero features of the pricier MOSFETs and i've never had an issue with it to be honest. Having 13:1 gears and a HT motor means the trigger response is great anyway and i'd probably not gain a lot from going to a AB++ or a Hybrid.

[Rogerborg]

2 hours ago, The_Lord_Poncho said:

T238 mosfet (V2 1.9) from Aliexpress

 

 

Hmm, those do look interesting.  Shame they don't appear to support burst modes, even on the higher end models.

[Sewdhull]

I have always made my MOSFETs but have just bought a perun hybrid for my mp5 because I fancied a burst mode and precocking.

It was the cheapest of those type otherwise I'd have sprung for a leviathan or just gone with my homemade one.

Time will tell if it was a wise move.

 

[Colin Allen]

2 hours ago, Sewdhull said:

I have always made my MOSFETs but have just bought a perun hybrid for my mp5 because I fancied a burst mode and precocking.

It was the cheapest of those type otherwise I'd have sprung for a leviathan or just gone with my homemade one.

Time will tell if it was a wise move.

 

I would take a Perun Hybrid over a Leviathan any day.

[Sewdhull]

Can't really compare the two.

 

Leviathan has better MOSFETs, more features, BT, data logging, trigger, etc etc.

Perun is half the price but offers what I'm after at the moment.

 

Sadly the leviathan can only be purchased via socom tactical minus all the normal choices you'd get from the manufacturer.

[DanBow]

So, I'm not going to get much from fitting one, although I like the idea of 2 or 3 shot burst, but I'm now a little confused about precocking!

 

I completely understand the theory behind it but my MP5 has a specified rate of fire of 700 to 850 rounds per minute. Even if that's wildly overestimated and we say 600 pm, that's 10 per second! Each shot is a tenth of a second! Are you telling me that you can really notice a difference or is it something we tell ourselves because we have a need to fettle/upgrade to make ourselves feel better?

[Rogerborg]

Precocking improves semi-auto response. It leaves the spring compressed so it only needs to be pulled just the last part before releasing.  Long term, this will weaken it (and perhaps stress the bushings/bearings) so you'll want to clear it at the end of the day / lunch / between games, depending how much you're bothered about a £10 part.

 

One consideration is that if you're running a strong spring and a weak motor, you can encounter situations where the motor is too weedy to start pulling an already heavily compressed spring, and it locks up.  It's not hugely likely, but I did experience it a few times before discovering the joys of half decent motors.  It's nothing that you can't inflict on yourself without a pre-cock mosfet by releasing the trigger mid-cycle though.

[Sewdhull]

I'll let you know if it's a real thing or more a feel thing. 

Having the shot fire immediately would feel right and be faster than one not precocked, maybe I'll measure it. 

Hope the motor doesn't mind.

[Lozart]

49 minutes ago, DanBow said:

So, I'm not going to get much from fitting one, although I like the idea of 2 or 3 shot burst, but I'm now a little confused about precocking!

 

I completely understand the theory behind it but my MP5 has a specified rate of fire of 700 to 850 rounds per minute. Even if that's wildly overestimated and we say 600 pm, that's 10 per second! Each shot is a tenth of a second! Are you telling me that you can really notice a difference or is it something we tell ourselves because we have a need to fettle/upgrade to make ourselves feel better?

 

For something like a DMR where you want super fast trigger response on Semi then yes, precocking does make a difference. On an MP5? Probably pointless.

 

[Rogerborg]

On 13/12/2023 at 12:25, Lozart said:

For something like a DMR where you want super fast trigger response on Semi then yes, precocking does make a difference. On an MP5? Probably pointless.

 

I'd say the exact opposite, for the very simple reason that if you're respecting your DMR MED then the extra few milliseconds are unlikely to matter, but if you're up close and personal, it can do.  I love the handiness of my MP5K in CQB, but the trigger travel and semi-auto response left a lot to be desired.

[Colin Allen]

On 12/12/2023 at 22:52, Sewdhull said:

Can't really compare the two.

 

Leviathan has better MOSFETs, more features, BT, data logging, trigger, etc etc.

Perun is half the price but offers what I'm after at the moment.

 

Sadly the leviathan can only be purchased via socom tactical minus all the normal choices you'd get from the manufacturer.

The Perun doesn't lose its settings and how much of the "ooh shiny" stuff on the Leviathan do you actually need/use?

21 minutes ago, Rogerborg said:

 

I'd say the exact opposite, for the very simple reason that if you're respecting your DMR MED then the extra few milliseconds are unlikely to matter, but if you're up close and personal, it can do.  I love the handiness of my MP5K in CQB, but the trigger travel and semi-auto response left a lot to be desired.

Precocking is useful for both; getting a shot off quickly when you pull the trigger is important at both short and long ranges.  However, I have never quite understood why folk run DMRs.

[Sewdhull]

I don't know really, probably none, altho I don't really need any of it I suppose. Just a MOSFET to protect the switch contacts.

 

I can see fast trigger being useful regardless of the gun unless it's full auto.

Much of shooting is feel, or not having to do thing and just be able to shoot.

Granted in Airsoft we have few of the real problems in shooting and if it were a no brainer (thank you America) everyone would use precocking all the time.

[Colin Allen]

30 minutes ago, Sewdhull said:

I don't know really, probably none, altho I don't really need any of it I suppose. Just a MOSFET to protect the switch contacts.

 

I can see fast trigger being useful regardless of the gun unless it's full auto.

Much of shooting is feel, or not having to do thing and just be able to shoot.

Granted in Airsoft we have few of the real problems in shooting and if it were a no brainer (thank you America) everyone would use precocking all the time.

Precocking is useful, as is high trigger sensitivity; both help you get shots off more quickly, which is a good thing.  

What is this "full auto" that you speak of?