ASCU technical discussion
 

I have installed a couple of the ASCU's now and I have a couple others interested in purchasing. The first one that I did is my "demo" and it is simply amazing! I love all the features, I have a Systema Magnum and a Systema Turbo motor so I have not experienced any reversals. At least not enough to screw up feeding, so I haven't noticed any.

I know that airsoftparts has sold 40 or 50 of these so there must be enough experience here to start this thread.

Has anyone run one to a front wired M4? Do you see any problem with doing a front wire setup with the ASCU? I think it can be done with A) a chafer around the wires where it goes through from body to front end and B) the operator being ever careful and vigilant when changing batteries and taking the gun down.

I am familiar with the thread at airsoft mechanics and although I agree that the implementation can lead to gear reversal I think that the complete trigger mech replacement idea is great. It is not quite as "slick" as my Systema Revolution Gearbox, but for $99 (plus installation) it is a great upgrade for any V. 2 AEG.

So, if we can start the discussion in these few areas, I will be grateful:

1) What are your experiences with the ASCU?

2) Is there any serious reason that the ASCU should not be used in a front wired M4 AEG?

3) Do you think it is a good upgrade for an AEG?

I have no first hand experience with the ASCU, but I did install some FET units on front-wired guns.

I used a 20ga wire with a simple pin/hole connection just where the battery wires have a connector. It works great and since it is just a "data" connection, you don't need an extremely efficient connection.

I really like the idea of the trigger replacement block, but I find that their software is lacking a bit. It would be easy to implement a motor brake without any extra hardware. An other solution would have been to use the cut-off lever to trigger an optical switch. Parts cost would be under 5c and I guess that the software implementation would be very simple.

The other thing I don't like is the size of the unit vs the features. It is really big for a simple MOSFET unit with very basic control features. I guess that if they didn't add motor break, they are not using a H-bridge setup. That means that only 1 FET would be required and it does not explain the size of the thing.

They should sell the trigger module by itself to let people use it with any MOSFET module (either SW or basic home-made). Might just build a trigger module with some board I have...

*edit*
Apparently they have implemented active braking since the last time I checked, and the semi-cut-off works properly. It is a lot more interesting now, but at 100$/unit, I still find it quite steep.

I've installed them in;

2X Rear wired G3
1X Front wired G3
1X Rear Wired M4
1X Front Wired M4
1X Rear Wired MP5

Only problem I've found with these is that it can be tricky to get the fire selector to line up properly in the different fire modes.

Aslong as you're using a SUPER High torque motor (Magnum, G&P M160 or higher) you don't need the ARL.

I'm playing around with how to mount one on a 7" front wired M4 right now lol

I can't see a front fired unit being a problem. use a piece of unshrunk heat shrink to protect the controller wires through the receiver. it's actually a very simple wiring job.

I've installed one in my FrankenMP5 and an M4.

Only minor issue is the M4 with the selector switch position as the gearbox is not lined up 100%.

Thanks Amos for the PM on motors. The m120 is not strong enough for the G&P m120 box although a JG motor turns an S100 just fine. lol Time to bug Jugglez for a bigger motor.

I just install mine. The only problem I had is the screw holding the sensor unit was a bit too long and it blocked the selector plate on the other side. I use a file to make it at the level of the shell and now it's moving smoothly.

I use my good old Classic Army Motor I had with my M15A4 when I purchased it in 2006. I seems to works well. Good cycling, good stopping. Semi, Burst and full auto work well. I also had the small issu of the selector swith position, not always detecting I'm on semi. If I go full auto and comeback to semi, it works.

I have a Systema M120 gearbox and I wire to the back. I order the madbull ACE stock tube and a magpul CTR stock to use with LiPo stock battery.

Note that ASCU warning for low battery even on NiMh not just LiPo. I think ASCU use now the cut off lever to detect cycling... and use 2 MOSFET unit to work. It maybe the reason it's that big.

Next step, field test.

I was having overspinning problems with my Systema 400fps Gearbox with the Jing Gong M-93 High Power motor, the ASCU solved this, and now the firing rate is awesome, I've done a short video of it:

http://i108.photobucket.com/albums/n...h_MVI_1669.jpg

I have installed one in a SR25, awesome performance again. Has anyone had a failed unit? I believe I saw Amos post a couple of months ago that he broke one on a Prometheus Hard cut-off lever.

I have a "demo" here that I left a LiPo (7.4v 1600MaH 20c) in for a couple of weeks while I went to work. When I got back it was completely drained. I think that the claims of "LiPo safe" are bogus. Anyone else have a problem with the ASCU draining batteries when not in use. Is it supposed to be "powered up" any time it is connector to a power source? Should I be removing the battery because it is powered up and draining the battery at all times?

Yes, I know you should remove a battery from your gun any time you are not using it. Don't need that post, just an answer to my question. :D

Its like ANY mosfet,

to be "Lipo-safe" it needs to draw a little bit of current to monitor it.

You shouldn't be leaving batteries plugged into ANY airsoft gun. Full stop.

ESPECIALLY ones with a mosfet as that can drain it to absolutely nothing and damage the batteries.

I would charge that LIPO outside next time you do. Lipos can be dangerous if they're brought to absolute zero.

And yea, the Prometheus hard cut off lever is too thick and on rotation it'll break off the sensor.

Other than that I haven't had a problem except for the shitty wire shielding that comes with them (but I re-wire everything anyways lol)

Thanks for the quick answer. I know, I know that I shouldn't leave batteries in them, and I do it too often. I especially have to watch out for the LiPo's as they can be a fire hazard and should be stored safely.

I also find that the piece of shielding (unshrunk heatshrink I think) is too long and I have to trim it shorter each time I install one. Another problem I have had is that the ribbon cable always ends up shorter than the power cables. I usually tie a loop in the power cables with a tie wrap so that it will take the strain of any pulling rather than the ribbon cable.

Otherwise I think they are a straightforward install.

Did this to me too, after the first game, I've let it plugged, and when I wanted to record the video there was no power left in the battery...

Have any of you guys installed and gamed/field tested both the ASCU and TM3 units? Which one did you like or performed better? I have already used 2 TM3's in my previous builds and I would like to try the ASCU on my third build.

The way I'm building right now:

V2 = ASCU
Anything else = TM

I will order one around New Year and install it in an ICS build-up I was asked by a friend... They state not to use it in ICS rifles, but I can't understand why... I made a mock trigger plate (for eventually use with the FET unit I am working on) and it physically fits no problem. They state on their website that the safety won't work... but I still don't see why.

The safety works by disconnecting all three prongs from the back of the sensor/trigger pack... since ICS mechboxes still use reg. M4 selector plate... I don't see it being a problem. Maybe the stock ICS plate is a millimeter too long and keeps the connection, but that would be solved by changing the selector plate.

other than the obvious split box design, what differences are there between the ICS and a standard v2 box? I don't have enough of a working knowledge on the ICS design to formulate a possible reason.

Anti-reversal is attached to a lever that protrudes on the right side of the mechbox shell. That lever is then pushed by a little metal plate that is in the way of the forward assist, releasing the spring.

The front section of the lower, under the mag catch guide continues up to the end of the mag catch guide.

The rear part of the upper mechbox is a bit longer than a regular mechbox upper part. The top is also at least twice as wide.

The receiver is a bit longer at the rear near the buffer tube to allow the lower upper mechbox to clear. The buffer tube guide is also threaded at the tip to allow the wires to pass in and to let the mechbox open.

I will post a side-by-side picture of a TM mechbox shell and ICS mechbox shell. The lower mechbox is exactly the same as any V2, every hole placement is the same. The top of the lower mechbox is also grinded ruff, suggesting that they use a V2 cast mold with a plug, and then clean off the burrs.