Gate Warfet anyone?

[Red Dot]

So anyone play with these in person? Looks like the only solution to put in my Masada because of the trigger switch. Any impressions would be welcome.

[lurkingknight]

do you want just a basic mosfet that works with a microswitch, or do you want all the fancy features that most people think are cool but never use?


gate fets are ok if you have a lot of space (because they're huge) they do have some good features. Their pricing is not terrible.

The drawback is that the fet units they chose to put in their product have amperage handling in constant and peak draw is just barely adequate for most stock and mildly upgraded builds. The faster gearset and more powerful motor you go, the higher the amp draw at constant and even higher during initial startup spike. It's not uncommon to see amperage spiking near 100A on a tienly or lonex 13:1 build that settles back to around 20A.

[Red Dot]

That's a good question, I think I would like some of the features like replacing my full auto with a burst but I'm still on the fence about AB.

My Masada is mildly upgraded in my opinion internally, Lonex stock ratio gears with bushings and a SHS HT motor.

Luckily in the handguard I have a lot of space for the FET.

I might want to bump up to 11.1s but again not 100% sure if the performance gains are worth the additional stress on Internals.

[EOD Steve]

Originally Posted by Red Dot

I might want to bump up to 11.1s but again not 100% sure if the performance gains are worth the additional stress on Internals.

Specifically what internals would undergo additional stress by moving to 11.1v?

[EOD Steve]

Originally Posted by lurkingknight

The faster gearset and more powerful motor you go, the higher the amp draw at constant and even higher during initial startup spike. It's not uncommon to see amperage spiking near 100A on a tienly or lonex 13:1 build that settles back to around 20A.

Bro - I gotta tell you about a new motor I've been using.

[chaz]

Originally Posted by EOD Steve

Bro - I gotta tell you about a new motor I've been using.

Well.......?

[Red Dot]

Originally Posted by EOD Steve

Specifically what internals would undergo additional stress by moving to 11.1v?

Specifically the gearbox? Not sure how a microswitch trigger holds up versus the standard trigger.

[cetane]

Originally Posted by Red Dot

Specifically the gearbox? Not sure how a microswitch trigger holds up versus the standard trigger.

With a fet with debouncing will hold up as well as standard trigger contacts.

[Red Dot]

Sounds good, still would like feedback of people that have used this FET... I know Duy sold out of them so they are out there.

[EOD Steve]

If you're using 7.4v, your ROF isn't high enough to require AB.
Ergo, if you don't require AB, then why do you need the debounce feature with the microswitch?

Are you aware of the cause and effect of microswitch trigger bounce?

[Red Dot]

Originally Posted by EOD Steve

If you're using 7.4v, your ROF isn't high enough to require AB.
Ergo, if you don't require AB, then why do you need the debounce feature with the microswitch?

Are you aware of the cause and effect of microswitch trigger bounce?

As far as I understand microswitches can overheat mosfets that aren't designed to work with them, had the BTC guys mention that a while back when I inquired about their products in a Masada via email.

[EOD Steve]

It has been widely discussed since 2011 around the time of microswitch introduction that a debouncing algorithm is only required when AB is involved. Simply put, an AB FET will attempt to apply reverse voltage when it detects that the switch is in the off position, which can occur when the microswitch bounces with weapon vibration. The rapid voltage swings is what causes the overheat. Rapid application and cessation of forward current alone especially if the motor is already in motion does not represent a large increase in current draw.

Since we're throwing names around now, here is an old thread authored by the mentor of "the BTC guys" (it's only one guy by the way) - Terry Fritz aka Gandolf, who remains quite active to this day.

http://www.airsoftmechanics.com/index.php?topic=4530.0
Here's the relevant excerpt:
"The rel problem is when an active braking MOSFET thinks the trigger is released (sub 1mS) and slams in the braking FET to stop the motor... Then 1mS later the trigger signal says "just joking!" keep the motor on... :P :P That is about a 300 amp "joke" for an active braking unit to "process" there like 100 times every second!!!!!!!!! T"

You may also want to take a look at this to understand the phenomenon.
http://extreme-fire.com/Micro-Switch-Bounce.pdf

With regards to actual first-hand experience, I recently installed a standard FET on a PTS Masada running 11.1v lipo with no ill effects after 1k rounds of mixed auto/semi fire. I anticipate the owner will provide me with an update as the season progresses.

[Red Dot]

Great, thanks for the info. Still would like to see actual first-hand experience with this particular product.

[lurkingknight]

I have 3 guns with burst fire controllers. None if them have burst enabled. I only use them to lower full auto top speed. Nor do I have ab enabled on any of them. A well built gun only needs a basic fet for most of the benefit anyone would want.

[danhay]

Originally Posted by EOD Steve

Bro - I gotta tell you about a new motor I've been using.

Do tell ... the suspense is mildly aggravating ...