FCU Options

When looking for electronics to power one of our airsoft engines in an AEG to HPA conversion, there are two main components: The trigger board and the FCU (Fire Control Unit). We offer two options: The Spartan Electronics board is a trigger board and FCU all-in-one design. While limited to only V2 gear boxes, the design enables the Spartan to take up less space and makes the system more cost effective and easier to set up. Our Gen 2 Premium FCU is a standalone FCU that connects to a separate trigger board. The Premium FCU allows for more options in fitment, tuning, and fire modes. Check out the information below to see which is right for your needs.

The Spartan Electronics board is a trigger board and FCU all-in-one. The key advantage of the Spartan Electronics board is it’s simple and robust design and lower price point. Settings are primarily manipulated with use of the trigger.

3 Available Fire Mode Presets
• Semi / Full Auto
• Semi / 3-Round Burst
• Semi / Semi
*Additional modes available in MTW version.

8 Quick / Easy ROF Presets
Select a preset from 10RPS to 33RPS by holding down the trigger as it fires three-round bursts until desired ROF is reached.

12 Quick/Easy Dwell Presets
Set dwell by holding down trigger as it fires once per second until drop in FPS is noticed, then double-tap to step back up one preset.

Available in the following options:
 INFERNO V2 Spartan Kit
• REAPER V2 Spartan Kit
• Individual
• MTW Version

The Gen 2 Premium FCU is a standalone FCU and requires a separate trigger board. The key advantage of the Premium FCU is a greater variety of available fire modes, more precise setting values for dwell and rate of fire, and an intuitive LED menu with tool-less button style programming.

Set any of 7 fire modes to for each selector position
• Full-auto
• 7-Round Burst
• 5-Round Burst
• 3-Round Burst
• 2-Round Burst
• Single Round
• DMR Mode (Semi-auto with 2 second
delay between shots)

Precise ROF Setting
Set rate of fire to any integer value from 1 to 63 RPS.

Precise Dwell Setting
Set dwell precisely from 3 to 20 milliseconds in increments of 0.25 milliseconds.

Additional Features
• Short detection
• Improved stiction and trigger-reading algorithms

Available in the following options:
 INFERNO Premium Kit
• HYDRA Premium Kit
• REAPER Premium Kit
• Individual
• MTW Upgrade Kit

For more detailed information, see the Owner’s Manuals!

Spartan Electronics for MTW-Spec with Physical Selector removal/installation (Video)

You can find full instructions on how to remove/install the MTW Spartan Electronics board in the MTW Spartan Electronics Owner’s Manual, or you can follow along with Rich in this video. If you’re installing the new board with optical sensor, see this article instead!

Video transcript: on today’s edition of what the tech we will be showing you how to install water-resistant electronics as well as just do basic maintenance on the electronics in your MTW so let’s get started so today we’re going to talk electronics we’re going to show you how to remove the electronics from your MTW how to swap them out or and we’re gonna talk about some of the basic features how they’re designed how they work all that kind of stuff alright so first thing we’re gonna do is we’re gonna separate upper and lower receiver pop the two pins if you need to use if they’re a little tight you can use something like the back end of a screwdriver that isn’t gonna damage the surface to help get them started we’re just gonna completely remove the upper from the lower right if you have a battery installed go ahead and unplug the battery always unplug the battery before doing anything with the electronics so before we go any further let’s talk about a few tools that you might want some of these are necessary some of them are will make your life easier but you may be able to get by without 1.5 millimeter allen key is essential you’re going to need this you will also want a set of needle nose pliers of some sort and a flat head screwdriver first thing we’re going to do is we are going to loosen the screw holding the trigger on to the trigger pin this is just a set screw right in front of the contact block here you’re just going to loosen it up about a turn or so and we should find that now we can move that pin okay before I remove it I’m going to disengage the spring from the trigger and once it’s out I’ll show you how this is put together you’re going to disengage the spring that’s attached to the trigger and then you should be able to easily push that pin right out maybe a little bit of friction on it but it should come out fairly easily okay for the front pin what on the real gun is the hammer pin there are two possible retention methods but this one has on it is what we started with and it just has an o-ring that has it gives some friction I to keep it in place so that way if you have that it can just be pushed straight out all right what we switch to pretty early on just to give a little bit more positive retention in this area is one of these little hairpin clamps this is a very small clip but what it does is it snaps into the groove on the on the pin this is where your pliers come in handy it snaps into the groove right there okay so that’s where it’s going but we’re going to put it there inside the gun just so you can get a picture though of where it’s going when we reinstall it it’s going to sit basically right like this so this is clip is going to sit right on the inside edge and it’s going to retain the the pin in there so it doesn’t slide you know okay but for now we have that pin out so we can remove our electronics pull the wiring out and we’re going to gently remove the electronics don’t just yank them out kind of wiggle them up and I’ll show you why in just a second okay here’s our electronics bar on this board there’s a little spring here this spring helps keep the board located but it is attached to the board it’s it’s glued onto the board and we want to be careful that when we’re removing and installing it that we’re not pushing a lot on the side of this spring and kind of shearing it off the board so just want to be gentle in that area this what we have here is our water resistant electronic so it has a special coating that helps mitigate water damage so it’s pretty effective we have not yet had one of these destroyed events merging it but we don’t recommend it and certainly if you do get your gun wet even with the water resistant electronics you need to go through and clean everything and dry everything just to avoid corrosion and other issues like that from occurring but this is our board and let’s talk about a few basic features this is our selector switch back here if will fire in semi if the selector switch is held down if it’s released it will fire in auto this is your trigger switch it is a clicky switch this is your empty mag detection so that’s what the lever on the magazine indicates on and this is your bolt release switch so your contact points here and these are replaceable so if you loosen this screw here if these get damaged too badly you can see this is a demo gun and has gotten beat up a bit but the spring has gotten a little bit distorted it’s actually still working just fine so I’m not going to worry about it right now but you can easily replace those if they do get damaged you can loosen the screw slide your contact springs out drop the new ones in and tighten it back down okay but that is the basic overview of the board let’s go ahead and take a look at the trigger on the trigger we have two screws on the production version this is a this is a set screw I apologize this is a set screw this is where it is on the production but they use both use a 1.5 millimeter allen key this is what clamps down on the trigger pin so that it won’t slide out and this adjusts the travel of your trigger so you can adjust the pre travel on your trigger this spring when it’s installed in the gun this arm sits along the bottom of the trigger pocket and this arm see if I can hold on to it here hooks right there so when I said disengage that spring what I’m doing is I’m going in there and just popping the spring up and off of the off of the arm here that it’s caught on so let’s go ahead and reassemble everything here first we’re going to put the trigger back in I put the selector in auto position makes it easiest to do this so it can be done in any position drop the trigger back in and we want the trigger to be sitting over on the left side of the gun we’re going to take our electronics the wiring should go around the spring and pin position here and this will slide in again I’m going to make sure that I push in on the spring and get it inside the trigger pocket there as we slide it in and this will sit the board actually sits right beside the the trigger and then we’re just gonna position it get everything right in place where it goes okay now I’m going to install the trigger pin it doesn’t matter which direction you install the trigger pin but we’re gonna Center it up on the gun and then I’m going to tighten down this screw that holds on to the trigger pin so now we’re going to show you how to install not with the o-rings but with the little clip here which most of you probably is what you will have okay first of all we’re going to install the pin from the right side of the gun to the left side of the gun but sorry we’re going to we want the pin to end up in this orientation there are two grooves on the pin we want the groove that’s closer to the end to be on the left side of the gun we’re going to I again get this installed you may need to make sure the board is scooted all the way forward tap it gently you shouldn’t need a lot of force on this a gentle tap should be all you need if you need more than that check that everything’s lined up properly okay so at this point my pin is installed and I need to do the clip alright so for the sake of this video so that you all can see it we have an assistant holding it what we’re gonna do is we’re going to hold on to the clip like so you’re gonna hold the head of the clip in your pliers now to install this the clip needs to be going straight down not at an angle it needs to be going straight down like this so what I’m gonna do is I’m gonna use my flathead screwdriver just to pull that spring just a little bit away from the edge inside wall and then we’re gonna clip the clip down in place make sure it’s seated completely and there we go and now you see the spring is retained or the the pin is retained so it can’t slide either direction okay last step is we need to engage our trigger spring now what we’re going to do is use our flat head screwdriver and we’re going to push down on the arm of the trigger spring using the angle of the head of the screwdriver to hold this spring up against the wall there’s a gap between that that block on the trigger that we’re trying to catch on and the wall I’m going to push it down past the block and then again you twist the screwdriver so that it snaps over and up against the wall I’ll do it one more time just so you can hopefully see I know it’s going to be a little dark in that trigger like it but I’m hopefully you can see what’s going on so I’m using the angle of the screwdriver to hold the spring up against the wall once I get it underneath twist the screwdriver and an old pop into place now we’re all set wiring needs to go to the back and you can reassemble upper and lower as normal so we’re going to tack these on at the end and just as things to things to keep in mind one your spring for your bolt catch here it’s this small spring you may it may come out of position while you’re working on your electronics so just be aware of that it drops down into a little cutout right underneath the arm so just keep an eye on it and make sure it’s positioned properly before you reinstall your electronics that’s easy enough all right the second is what to do if you if the spring attached to the board pops off first off don’t panic this is not the end of the world basically this is the the adhesive we use to hold this on is essentially just an assembly guide or an assembly aid if you will so that it makes it easier to assemble but if we pop it off there you go broke they broke the glue that was holding it on there we can still reassemble it it’s oh it’s a little more tedious but I’m going to show you how to do it you can attempt to redo it if you want a little bit of superglue is okay just make sure if you want to wreak Lou it that you don’t get any glue in the inside the Nepean area where you go through here because that’ll that’ll obstruct the pin but I’m gonna go ahead and show you how to do this I if you break the spring off because if you install it and uninstall it enough times sooner or later it’s gonna happen again it’s it’s made to aid with the initial assembly but you know if you’re and if you’re gentle with it generally it holds up pretty well but if you’re doing you know if you’re tearing your gun down quite a few times doing different things trying different things sooner or later you’re gonna you’re gonna pop it off so let’s take a look at how to install it all right so what I’ve done to get us ready is I have gone ahead and reinstalled the trigger tighten down the screw and that just gets the electronics kind of held in position where they are supposed to be the next thing I’m going to do is I’m gonna get the pin started and I’m gonna set the pin just it’s a little hard to see down in there just so that it is sort of flush with the front side of the board and this is just making sure the board is actually in position where it needs to be before we track them before we put the spring in okay next thing I’m gonna do is I’m going to grab the spring with a pair of pliers here okay and you can see I’m grabbing about three coils and just kind of squeezing it together this is gonna compress the spring let me drop it down in and I’m gonna line it up with the with the pin then go ahead and press the pin through okay and there you go so you can see it’s not it’s not a big deal we just put it on there to make the installation a little bit easier as we’re assembling them if it comes off don’t freak out it’s not that difficult to get in just takes a little bit more doing so that’s it for the electronics today if you have any questions before be sure to shoot them over to us and as always we appreciate your support and we’ll see you guys out on the field

Spartan Electronics for MTW-Spec Fire Modes (Video)

MTW Fire Mode Select Demonstration. See the instructions below for AEGs.

The Spartan Electronics board can be cycled through several different fire modes as listed below. To advance to the next fire mode, set your gun to semi mode and hold the trigger. After 5 seconds (MTW version) or 10 seconds (AEG Version), the board will advance to the next setting.

MTW (Hold 5 seconds to change modes)
• Semi / Full Auto (Default in US)
• Semi / 3-Round Burst
• Semi / 2-Round Burst
• Semi / Semi (Default in UK)
• 2-Round Burst / Full Auto

AEG (Hold 10 seconds to change modes)
• Semi / Full Auto (Default in US)
• Semi / 3-Round Burst
• Semi / Semi (Default in UK)


*Boards sold in Germany are locked in
Semi / Semi mode.