[Ursu13]

Hi guys,
I just bought 2 DIY MOSFETs from a guy that knows his business, but surprisingly they don't work. He told me he checked them before shipping. They are plug-and-play ones, with Deans (T) connectors, something like the MERF ones.
The thing is that without them, my airsoft guns work perfectly, but the moment I connect them between the battery and the replica, nothing happens. I press the trigger and everything is dead.
The guy is something like "Check your wires. It's not my job" and that's why I ask you guys. Thanks.

 

[Mental96]

Well, have you checked your wiring? Does the fet need a trigger pulse to operate or it just plugs between battery and motor?

 

[Ursu13]

Yes, I checked the wiring. As I mentioned before, it works without the mosfet connected.
From what I understand from the seller, it doesn't need to be programmed, just plugged between battery and motor, like you said.

 

[Mental96]

Hmm, is your battery fully charged? What battery are you using? Is there any battery protection circuitry on the FET that may interfere with your specific battery?

I dont know what fet is that you are having, but there really arent many things to go wrong really.

 

[Ursu13]

Okay, problem solved. The seller finally agreed to help me. So it wasn't just a plug-and-play mosfet like he showed me in some photos, but actually I have to solder another wire from the trigger to it. Oh well, I guess it's like any other mosfet out there...
Thanks for the help, Mental96.

 

[CrusherW9]

Good thing you have to solder it. Those inline mosfets that you put in between your battery and stock wiring don't do anything.

 

[Ursu13]

Really? Not even the MERFs?

 

[threshold]

Actually best way to install MERF is to solder it. That way you get more functionality and that is from MERF's descripiton in my local airsoft store.

 

[CrusherW9]

Really? Not even the MERFs?

From the Evike description "No modification to your AEG is required just plug and play, but will not stop Trigger contact Arcing."

The idea behind using mosfets in airsoft is to send a very low amount of amps through your contacts. When the contacts complete the circuit (you pull the trigger), the mosfet get's switched on and sends either as many amps your battery can provide, if you're limited by your battery, or as many amps your motor pulls, to the motor which bypasses the contacts. Those inline mosfets that don't require any soldering don't separate the contacts from the motor.

So while they don't save your contacts, they do add other features which I'm sure you're aware of.

 

[Ursu13]

A little bit of necro, but since it's my own thread, I thought why the heck not?!
So, at the last 2 days mil-sim event my AUG decided to break the rules for DMR and shoot only on auto. Now I got a 3 days one and I really don't want to cause any disputes.
After grinding my nerves to make it work, I am giving up and I'm posting some pics in hope that someone can help me:





Colour legend: green - the actual mosfet; blue - a third female plug (probably the signal one?); yellow - the fuse burned and I bonded the wires together.
Where the free male deans connector is, comes the battery.
Now, in this setup the gearbox only shoots on auto. On semi I pull the trigger and nothing happens.
From the diagrams I found on Google Images, I thought I only had to desolder the plus wire that goes from the mosfet to the trigger and solder it back on the plus of the motor, something like:



But in this configuration I get a lot or arcing and the gearbox starts firing on its own.
So, my question is: HOW IS IT DONE for the love of God??
I'm sure there is something so obvious and simple that I can't even see it.

 

[CrusherW9]

Your current config is incorrect. Your positive wire is sending all of the current through your trigger contacts as it goes to them instead of the motor. The diagram you linked at the end of your post should be correct. And if you want it to be semi only, just don't wire in the full auto contacts.

 

[mike0brien]

This is how one of my aug's has the mosfet wired up... Doesn't really matter but the forward contact connects to the forward side of the trigger on the other side of the gear box.

 

[Ursu13]

Thank you, everyone, but I already sent it to an airsoft shop tech department. I didn't had any more patience for it and I prefer to pay a small amount of money and receive it working 100%.

 

[philbegas]

I hope you had better luck than I did with that. When I sent my gun to ASGI tech for repairs they called me and told me somehow my mosfet had broken >.<

 

[Ursu13]

I'm expecting this outcome too. They have GATE mosfets on stock, so if that happens, I'll ask them to install one of theirs. But my money is on the cut-off lever.
So far they haven't called back, so I'm still waiting to see what the problem is.