Airsoft Smart Control Unit a.k.a ASCU

[jagillham]

Airsoft Smart Control Unit

Introduction

For those that do not know, the ASCU is a new type of MOSFET which replaces the original trigger assembly, which gives extra functionality. Considering it is a product that makes some bold claims, and is pretty much unique, there is surprisingly little review information regarding the ASCU online. As far as I know, first launched in 2006, yet nobody seems to have one!

Currently only available for the V2 gearbox, which limits you broadly to M4/M16/MP5 variants. RRP is $99 (~£65)

The unit itself claims:

- Crisp Trigger Response
- No Gearbox Jams
- Increased Rate of Fire
- 3 Round Burst
- Increased Battery Life
- Increased Spring Life
- Lipo Ready
- Built In Lipo Alarm

Installation

To install this unit, you do need to be comfortable with opening up gearboxes. Apart from that, there is no specialist skills needed. So if you are happy doing things like changing springs, you'll be fine with this.

The ASCU arrives with its own small 15 page manual, which gives step by step instructions on how to fit the unit, with pictures for reference. In short the original wiring and trigger assembly are removed and replaced with the ASCU. The anti-reversal latch and safety bar are also removed. I'll come back to them parts later.

The internal part is a micro switch, and a sensor which detects the cut off leaver.

The gearbox work was very little trouble, the placement of the external MOSFET and fuse proved to be a little trickier. I installed this on the G&P M4 Sentry, which is a fairly typical M4 variant. Within the stock / buffer tube had to fit the battery, MOSFET, excess wiring and fuse unit. A shown below, there is quite a lot to fit in a small area.

To squeeze everything in requires some careful placement, which meant the loss of the sliding stock movement. First step was to identify where the stock will sit, personally on setting '3' (of 5) I liked best.

The trick seems to be to bring the MOSFET into one side of the battery compartment like so...

then bring the fuse part onto the other side like so....

This leaves the tube largely free to accommodate the battery, in this case a...

7.4v 1200mah 20+C lipo (24A continuous, 36A burst, 137 x 20.3 x 11.4mm).

I believe a....

7.4v 1400mah 20+C lipo (28A continuous, 42A burst, 171 x 19 x 12.9mm)

.....could just about fit with the stock on setting '3'.

Functionality

I'll run through the claims, and what I have found...

Crisp Trigger Response

The ASCU reduces the trigger movement required to shoot, which in turn speeds up the process. As with any MOSFET, the power goes direct which also helps. Finally, with a lipo battery, this was shooting as quick as I could pull the trigger.

No Gearbox Jams

The ASCU will always complete a full cycle and has no anti reversal latch, so this eliminates the common V2 gearbox lock up. No more switching from semi, to auto (and back again) to make semi work! No problems to report so far.

Increased Rate of Fire

As with any MOSFET really.

3 Round Burst

On fully auto, a quick pull of the trigger will give a 3 round burst, so long as you let go before the 3rd shot. If you press and hold, normal full auto. If you are really quick you can tap the trigger, and let go, to see the 3 rounds complete even once you have let go of the trigger. Obviously this takes a fraction of a second, and is hard to spot.

Increased Battery Life

The theory behind this is that the MOSFET is more efficient and has less resistance over the traditional copper contacts. I'm not sure if it will make an awful lot of difference over one skirmish though.

Increased Spring Life

The spring always comes to rest at the furthest most position in the gearbox, therefore won't be stored compressed. Again, not sure how much difference this really makes.

Lipo Ready

The unit is sold as "lipo ready", as you'd expect really.

Built In Lipo Alarm

A rather good feature, the ASCU will beep and cut off when a lipo battery becomes almost dangerously flat.

Conclusion

The ASCU is not a cheap buy, especially when you add postage from Hong Kong. If you ordered this with other bits, you'd be looking at around £80 - £90 total into the UK. However, when a Extreme Fire MOSFET from the USA comes in at around £70, the price difference is not massive.

Running on the above detailed Lipo it works fantastically. On a much stronger lipo (7.4V 1900mAh 20C+, 38A continuous, 57A burst) I am getting double feeding from the overspin. At this moment, I am not sure if the low rated spring, high rated lipo, or the Active Braking on the unit to blame.

Feature wise, the unit is very nice. Personally the small trigger movement, 3rd burst and inbuilt Lipo alarm are real winners for me. Another thing I like is with the removal of the safety bar, the trigger still moves on "Safe" (ofcourse does not shoot though!).

The biggest downside so far would be the size of the external parts. You do need a fair bit of space to accommodate them. I was looking to fit a PTS MOE Stock, but there won't be enough room to do so.

All in all, seems to be a great little add on for an AEG.

[cpldave]

Re: Airsoft Smart Control Unit a.k.a ASCU

Nice review jagillham! Other than the Airsoft-Systems and this review, there does seem to be a large gap in reviews for the SCU.

I think I will eventually get one of these when the release the ICS split-gearbox version of the SCU. I especially love the full-cycle completion. Was there a sensor that you had to fit under one of the gears or is it timing based?

One thing that concerned me was the over-spin you mentioned. Is that caused by the motor not stopping quick-enough with active-breaking and cycling again? Perhaps a Systema High-Torque motor would have a better chance at stopping over-spin because it has stronger magnets. What do you think?

Thanks again for the review.

Cpl Dave.

[jagillham]

Re: Airsoft Smart Control Unit a.k.a ASCU

I'd not hold your breathe for the ICS or V3 version, they seem to have been "coming" for a while now, and this unit has been out 4 years! A total guess, but I wonder if the ASCU has had poor sales (judging by the lack of reviews!) therefore the project has slowed right down?!

Was there a sensor that you had to fit under one of the gears or is it timing based?

I've tried to outline the moving parts below...

The sensor (in green) is connected to the cut off leaver (in red). As the gears cycle, the cut off leaver moves, which is how the unit knows a cycle in complete. Just for reference, the only other moving part is the button (in blue) which is hit by the trigger to shoot.

One thing that concerned me was the over-spin you mentioned. Is that caused by the motor not stopping quick-enough with active-breaking and cycling again? Perhaps a Systema High-Torque motor would have a better chance at stopping over-spin because it has stronger magnets.

This is something I'll look into. The makers claim this will work with 11.1v Lipo, so I'd hope the active braking is not at fault. My G&P Sentry crono'd in today really low (275fps!!), Guarder SP90 spring, so maybe the crono was wrong. It could be the case the spring is too weak, combined with a well lubricated gearbox, fast M120 motor and decent Lipo, that everything is moving very fast, with little mechanical resistance to aid the Active Braking.

I'll fit a M100 spring later, see if that helps at all!

[rossy02]

Re: Airsoft Smart Control Unit a.k.a ASCU

Had the same problem with the rollback issue, so the AEG would double feed or not fire atall.

Basically this is caused because the motor is not strong enough and the pinion gear is therefore aloud to roll back.

I tried 5 different motors and after much testing have settled with the Systema Magnum, works perfectly. This is because the magnet in the Systema is much much stronger and therefore cannot roll back.

So I would suggest that if planning on using a ASCU a systema magnum motor is used.

Hope this helps a little.

Hope this paragraph sounds right, it did in my head but its late lol.

[HuntR]

Re: Airsoft Smart Control Unit a.k.a ASCU

Aren't i a gent letting you both have them at a bargain price XD

[sparrowhawk]

Re: Airsoft Smart Control Unit a.k.a ASCU

good review....tis certainly food for thought

[jagillham]

Re: Airsoft Smart Control Unit a.k.a ASCU

Double feed issue seems to be this:

Basically the ASCU design removes the ARL, and the bigger battery is causing over spin. The airnozzle pulls back, loads the BB, and fires in the normal way, but then the over spin pulls back the nozzle. This allows another BB into the hop unit, before the gears roll back slightly back the rest position, which pushes the BB into the hop rubber. Next shot repeats, so 2 are being shot at the same time.

Simplest cure is to put the Anti Reversal Latch back in. It will still over spin, but won't then reset to load another BB at the beginning of the next cycle.

[d_k]

Re: Airsoft Smart Control Unit a.k.a ASCU

do you think this will fit an ics split gearbox as well ????

[jagillham]

Re: Airsoft Smart Control Unit a.k.a ASCU

do you think this will fit an ics split gearbox as well ????

Nope.

They are releasing a specific version at some point apparently, although no work on date as yet.

Could be a long time coming due to poor sales!

[savill9]

Re: Airsoft Smart Control Unit a.k.a ASCU

Just ordered one of these today before reading your post, i have a rear wired m4 with the magpul UBR stock on and use 7.4v lipo's, do you think i am going to struggle to fit this all into the stock tube.

The UBR stock uses its own stock tube, not a standard M4 tube and its already a little snug on space with just the battery and wire already, let alone adding what seems to be quite a large mosfet.

[jagillham]

Re: Airsoft Smart Control Unit a.k.a ASCU

You might be ok, looks like there is "dead space" by the rubber butt stock?

[caffin999]

Re: Airsoft Smart Control Unit a.k.a ASCU

have you tried putting the arl back in jag to see if it has stopped the double feeding?

[jagillham]

Re: Airsoft Smart Control Unit a.k.a ASCU

have you tried putting the arl back in jag to see if it has stopped the double feeding?

On my "to do" list :D

I've observed the nozzle do the double push, so I'm 99% confident it will solve the issue.

[caffin999]

Re: Airsoft Smart Control Unit a.k.a ASCU

cool. I was under the impression (from reviews and such) you couldn't use it with the arl but i look forward to being corrected hopefully

[Clot]

Re: Airsoft Smart Control Unit a.k.a ASCU

Im not convinced of this claim of the 3rd burst. Stating that you have to listen and release the trigger at the right time to get it...

You can do that with any normal aeg.

My current mosfet does a 3rd burst without having to worry about timing...