How to avoid contact burn when playing Semi?
 

Hello,

1) If planning on playing Semi most of the time, how would I protect my gun against contact burn?

2) Having read about MOSFET units, since I'll be playing on Semi most of the time, is buying a costly MOSFET such as the MERF still viable, or are there better, simpler ways to avoid contact burn?

I have an VFC Hk416

Thanks you in advance!

Simple mosfets also protect your trigger contacts. They are cheap and fairly easy to install if you're any good at soldering.

You think the MERF is costly?

I don't know how much of an issue contact burn is; I have guns which are more than six years old (and I have not cracked their mechboxes at all in that time) and are still absolutely fine. I mostly shoot semi when playing and have not run across this issue.

Maybe if anyone who has had this happen to them can chime in? That would be great as I'm interested in reading about the causes/cures/prevention..

install mosfet. /thread.

Contact burning is really less of an issue than people think.
If your contacts corrode or get coated in carbon, there is something wrong elsewhere in your gun. It can be that you run too hard of a spring, bad shimming, bad motor, bad battery, a short somewhere in the wires etc.
Airsoft guns run on less than 10A. The trigger contacts are made large enough and beefy enough, even in clone guns to be able to handle that kind of load for ages.

If your contacts are burning, there is something else. By installing a FET, you will hide the symptoms, but not fix the cause.
FETs are really for when you are sure everything is perfect elsewhere, and you want better response (200% lower resistance across the whole wiring), or you know you run a heavy spring (400fps+), with good compression and there is no other solution.

I respectfully disagree with this over-arching generalization.

Never had any issues with my stock tm
Trigger contacts... Was never a consern either... Most of my guns have seen over a decade of use......

For a quick comparison, systema PTW's run at 16-18A at 400fps

"contact burning" (trigger arcing) is a symptom of high voltage, not high amperage. It's somewhat random what guns are prone to it, and it has nothing to do with how your gun is set up. It's the problem you have when you use a trigger designed in the 19th century, electricity arcs across contacts before the trigger has made physical contact, and that's what causes the burning. The higher voltage you run, the further away it arcs.
I've seen some 3s lipo guns run just fine without a mosfet, then I've seen them get burned up in just a few games, and I've seen them melt after just a few games.
I would say anything 9.6v or above should have a mosfet for sure.
Any gun with a battery under 2000mah should have a mosfet for battery efficiency
Any gun using C size NiMH cells or LiPo should have a mosfet to prevent the trigger block from melting

I'll probably be using a 7.4 LiPO battery; will that accelerate the trigger burning issue?

no. and considering you're doing mostly semi, you shouldn't need a mosfet to reduce heat buildup either.
But if you're using small batteries, it would really help battery efficiency