Mosfet for Mp5 Retractable Stock

[RonLancs]

Hi all, 

 

I’m looking for a Mosfet for CYMA MP5. I don’t want an internal one, it doesn’t need to be fancy but it needs to fit in hand guard or at the back of the gearbox. I’m using an 11.1 in it at the moment and it runs nicely but I want to save my trigger contacts. 

[Sitting Duck]

doubt if you will get anything smaller...

it's fucking tiny...

 

https://www.airsoftworld.net/perun-mosfet.html

[Davegolf]

Could also put a fly back across the motor.

[RonLancs]

5 minutes ago, Sitting Duck said:

doubt if you will get anything smaller...

it's fucking tiny...

 

https://www.airsoftworld.net/perun-mosfet.html

Nice mate that’s exactly what I’m looking for. Thanks. 

1 minute ago, Davegolf said:

Could also put a fly back across the motor.

What’s a fly back mate? 

[Davegolf]

Fly back diode, eats up the shutdown current created by a DC voltage motor, saves the brushes/commutator

[Sitting Duck]

10 minutes ago, Sitting Duck said:

doubt if you will get anything smaller...

it's fucking tiny...

 

https://www.airsoftworld.net/perun-mosfet.html

 

 

failing that - use a snubber/flyback diode across a NORMAL cheapo motor

don't put them on SHS/G&G types - well I wouldn't...

 

 

 

think kwa use this as some fancy bollox to save trigger contacts

but yeah it is a flyback diode to drastically lessent the sparks at contact

 

which incidently is not when the circuit if first closed as many think

but as the trolley pops and the switch opens once again - ZZAAPPP

a large massive spark jumps from the inductive load - aka da motaaa

and THAT is how your contacts arc n weld n shit

 

50p diode, schottky diode qwells 98% of the arcing

5 minutes ago, Davegolf said:

Could also put a fly back across the motor.

 

ninja'd coz dinner was being dished up - lol

 

WHY THE FUCK DID I QUOTE MYSELF ???

THOUGHT I WAS EDITTING THE POST DAMN IT

 

was looking for the kwa or king arms thingy with super duper trigger saver module

(it's a fucking flyback diode ffs)

[Davegolf]

Mwhoo haa!

[Sitting Duck]

2 minutes ago, Davegolf said:

Mwhoo haa!

 

 

[Davegolf]

You’d seriously fuck your self up with light-chucks!

[Sitting Duck]

24 minutes ago, Davegolf said:

You’d seriously fuck your self up with light-chucks!

 

oh yeah, there are moments when the bloke wouldn't have head or foot left

 

but still cleverly done - though each stick had a flyback diode installed I reckon

 

here kwa snubber/flyback bollox

 

 

 

The new KWA SLE - Switch Life Extender

 

https://airsoft.tiger111hk.com/m239/KWA/p37623/KWA-VM4-RONIN-6-PDW-AEG-2.5-Rifle-(Black)/product_info.html

 

nnaaaahhhh it's a snubber flyback diode ya cheeky marketing cunts

 

BUT - still more reliable than a G&G ETU I guess

[Sitting Duck]

 

Think I'll launch a new thingy too

 

Dynamic Electrical Assistance Nexus System...

 

 

[Adolf Hamster]

1 hour ago, Sitting Duck said:

 

which incidently is not when the circuit if first closed as many think

but as the trolley pops and the switch opens once again - ZZAAPPP

a large massive spark jumps from the inductive load - aka da motaaa

and THAT is how your contacts arc n weld n shit

 

I kinda wish i didnt need to arc-weld a 3-phase rated switch together with about 6kv worth of back emf to have learned that lesson (or at least remembered back emf was a thing)

 

And thats how hamster got banned from the electrical lab.......

[Shamal]

16 minutes ago, Sitting Duck said:

 

Think I'll launch a new thingy too

 

Dynamic Electrical Assistance Nexus System...

 

 

Quiet you fool..keep it under your hat. You could be on to something....😉

[Davegolf]

10 minutes ago, Adolf Hamster said:

 

I kinda wish i didnt need to arc-weld a 3-phase rated switch together with about 6kv worth of back emf to have learned that lesson (or at least remembered back emf was a thing)

 

And thats how hamster got banned from the electrical lab.......

Aaand that’s how Hamster got Adolf’d

[Sitting Duck]

as said the ICS & KWA motors are the "normal" cheapo China motor types...

they got them locking tabs at sides...

 

The SHS/G&G & others that have 2 allen screw/bolts fastening into a lock ring inside

(that CONDUCTS !!!)

there is a risk of shorting if you place a diode across them (perhaps)

but I wouldn't fit a flyback to a G&G/SHS motor like ICS clip shows

KWA does it a bit differently, wired in as a module in series so should work on G&G/SHS

(so some kudos to KWA I suppose but calling it a fancy name - jeeeez marketing BS or wot)

 

ICS method is the simple straight forward method & is fine for cheapo "tabbed" motors,

but bit tricky or risky perhaps on other motor types

as you may short shit out if not careful on lockring type motors

 

only saying this in case somebody tries to sue me for fireworks inside their toy gun

you can just wire it across the wires, just on certain motor types you MIGHT create a short

with the lockring motors - that's all

 

The diode needs to be across the motor, preferably as close as possible to motor

but can be a tiny bit further back (not much) or not quite immediately directly across motor

(like the tiny extra wiring dooberry in the KWA bollox)

HOWEVER - the diode MUST be between the switch & motor to snub the sparks

(in a non mosfet gun)

If you put the diode across the positive & negative wires BEFORE switch it doesn't snub the spark

So the diode goes somewhere across the motor & between motor+switch so to speak

 

There are a number of options, you can splice a diode in

& a mosfet should have protection in it anyway, where/what the protection is varies on mosfet model

(the 3034 is a more robust mosfet than the cheap ones like 1404's, a 1404 benefits from a flyback)

you can add a flyback to most guns, but usually it goes across or close to motor to snub sparks

Diodes - even mosfets nick a tiny tiny smidge of juice before they turn on, called the forwarding voltage

"Well hello there...", no switch on then, but you won't really notice it

and you need to prevent burning out contacts somehow for long term reliability on 11.1v

 

Flyback/Snubber/Schottky are a cheap effective method to drastically reduce the damage on 11.1v 

 

I'm not an electrical engineer so be warned trying to slap schottky's across G&G's, SHS's etc...

on the cheapo "tabbed" motors you will be fine to wire it across the motor itself

[Adolf Hamster]

29 minutes ago, Davegolf said:

Aaand that’s how Hamster got Adolf’d

 

The moral of this story is:

 

If you're gonna fuck up, fuck up when nobody important is looking

[Sitting Duck]

20 minutes ago, Adolf Hamster said:

 

The moral of this story is:

 

If you're gonna fuck up, fuck up when nobody important is looking

 

naaahhhh - you can become famous thanks to YouTube...

 

 

 

if this bloke suffers a cardiac arrest & needs defibrillator

well it better be a 3 phase one or something coz how he is alive is beyond me

[Adolf Hamster]

1 hour ago, Sitting Duck said:

 

naaahhhh - you can become famous thanks to YouTube...

 

 

 

if this bloke suffers a cardiac arrest & needs defibrillator

well it better be a 3 phase one or something coz how he is alive is beyond me

 

See you answered your own statement there- that bloke already has the market cornered.

[Sitting Duck]

true dat

[RonLancs]

You reckon this’n will be ok? 

[Sitting Duck]

YUP - it is the classic China motor,

with the 2 tabs punched shut at sides.

The 2 screws you fit the Schottky diode to do not enter a lockring like on SHS/G&G's,

 

Fit a cheapy Schottky diode on there,

thus reducing the sparks from motor's inductive load,

when switch re-opens as trolley pops on semi,

(or you release trigger on auto).

 

The sparks come from the power shutting off at switch,

as switch opens, but energy is stored in motor/relay,

and THAT is where/when the spark jumps across the opening contacts...

 

The diode just tells the sparks to fuck off.

 

Wrap the diode leads CLOCKWISE if possible...

for some reason in ICS video they wrap it counter-clockwise,

I mean it will work & all that...

just if you wrap wires CCW they can tend to want to fight their way off the screw you tighten CW, so if you wrap the wire/lead CLOCKWISE it tends to fight less as you tighten screw...

 

Bit like when people apply PTFE tape to plumbing compression joints but wrap the wrong way & wonder why tape is stripping away as they tighten joint. Again wrap the tape clockwise the way the nut tightens and it doesn't fight to undo as you tighten.

 

Same with wires/leads, wrap CW if possible so it fights less trying to jump off screw as you tighten

 

[RonLancs]

4 minutes ago, Sitting Duck said:

YUP - it is the classic China motor,

with the 2 tabs punched shut at sides.

The 2 screws you fit the Schottky diode to do not enter a lockring like on SHS/G&G's,

 

Fit a cheapy Schottky diode on there,

thus reducing the sparks from motor's inductive load,

when switch re-opens as trolley pops on semi,

(or you release trigger on auto).

 

The sparks come from the power shutting off at switch,

as switch opens, but energy is stored in motor/relay,

and THAT is where/when the spark jumps across the opening contacts...

 

The diode just tells the sparks to fuck off

You're a good'n cheers.