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Matrix / AIM Lipoly Ready 8mm Complete Gearbox for M4 / M16 series Airsoft AEG ( M120 / Back Wiring)

21 Customer Reviews

by Nicholas E. on 02/17/2015
"Very nice gearbox. I got it to drop into my old Dboys and it's done it's job beautifully.

Pros- good fps, rather quiet, fits well, solidly built, and durable.

Cons- Semi-auto function is a little screwy, I have burst fire and full auto now. Wiring is extremely short.

I would absolutely recommend this and a bag of .25s to maximize the range of it.
by Sean D. on 12/09/2012

Absolutely wonderful. I bought this with the Matrix Magnum 3000 motor, performs like a dream.

First thing I did with it was void the warranty by opening it up. Inside, lots of nice parts. The spring guide stainless steel, as is the cylinder head. Unfortunately, the selector plate did not have contacts, and the wiring set didn't have them for the selector plate either. Wah. Didn't matter, cuz I bought a MOSFET system with a trigger set included, and I had a spare selector plate with trigger contacts. Works very well.

Has what the picture says inside.
Great performance.
Pre-shimmed gears. If you open it up, make sure they don't go flying off so you know where each shim was.
Powerful, well worth the price.

Wiring is extremely short, not even an inch out of the gearbox. If you try to fit it in your lower reciever, the tamiya connecter will probably rip off. It did for me.
No trigger contacts on the selector switch or corresponding ones on the trigger set.

Overall, a very nice gearbox, with a 363mm MadBull V2 6.03mm, madbull ultimate hopup, MOSFET, and this gearbox well outperforming a KWA SR10 without upgrades.
by Mathew U. on 12/19/2011
"I got this in the mail today and started building my AEG from scratch(almost).I'm really glad I got this pre-assembled gearbox, a little greasing and my gun was shooting amazing. Saved a lot of time. Only con is the wiring in the back was too short - would have rather seen regular wire crimps instead of a small male tamiya connector. After ripping that off all was good. Great product.

Suggest that you buy it with some extra wiring.
by Zachary F. on 01/25/2011
"GREAT!!! : ) I just got this today in the mail, and installed it later this afternoon. I had to do some rewiring, so having lots of extra tools laying around is a plus, plus I also used some of the wiring from the old Gearbox. I couldn't believe the thrill of when I finally got it all together. The M4 I installed it into was a G&P Zombie Stubby Killer.
by Krystyan L. on 09/08/2010
"Great bang for your buck. I also got the Matrix magnum motor to go with it. I got it for a custom build. It went in a King arms metal body and hop up and a Mad Bull black python 509mm inner barrel. It chrono'd between 450-460fps. Great gearbox so far.
by Velimir S. on 08/27/2010
"This is my third but first complete gearbox and it is best deal in whole wide world even with shipping for Europe. I have check more than 15 sites.

It gives 400 FPS with my stock barrel (Dboys CQB-R RAS II) and 420 FPS with Madbull VER II 363 mm barrel, DBoys hop up and stock rubber. I have bought Madbull hop-up but do not buy that because it doesn’t feed at all. I have placed review on that but who knows will webmaster approve it 
There are some differences that you can see on pictures and what they say in description so here is my review. Off course I already open it ;-)

Before this gearbox I try all other combinations of parts but I for my “spare” 500 FPS gearbox and other gun I chose almost same parts. For instance tappet plate can be aluminum as nozzle but I don’t like it because of weight and non-flexibility that could break sector gear or some other part. Piston and piston head also can be from aluminum and then you also have more weight and LOUD piston head. Body is tick, strong and nice designed with 8 mm steel ball bearings, SS ball bearing spring guide, Type 0 stainless steel cylinder so you can shoot with inner barrels that have length 510 mm +, double O ring CNC cylinder head that fits perfectly in cylinder and keeps compression very well.

Great AIM TOP gears but I have to shim them and to add some gear grease + they do not have small spring as you can see on a picture or on package. They have regular tubes-distances as all other gears. For me this is better than these small springs, because you do not have wobbling of gears that could destroy them after constant abuse of RC lipo that I use and you can shim them easily as all other gears.
Spring is irregular pitch tempered wire spring.
Very nice 14 teeth piston but piston head is not silent.
If you want silent piston head you should have concave piston head and you have to have silent cylinder head or to remove existing rubber from back side of cylinder head and to add silent dumper rubber. Anyway it is more silent that aluminum piston head and much more silent than my other 400 FPS lipo ready BB gun. Who want to be silent? Make noise as more as you can ;-). BTW compression is GREAT and ball bearing piston head also.
Nozzle have small O ring taht keeps compresion well and tappet plate is nylon also great.
Wires are short, but very tick, much more ticker that some other „upgrade“ swithes that you can buy on market. For me is not immportant because I have XT60 connectors for RC lipo and I will destoy this gearbox much faster than with regular 11.1 V airsoft lipo but ROF is incredible.

My warm regards to all US airsofters from sunny and hot Dubrovnik :)
by Stephen H. on 12/31/2009
"I guess I'll be the one person here who reviews this item and actually knows something about Airsoft.
For me, last time it was chrono'd at the field, it did 415 fps w/ 0.2s, so that means I'm getting more FPS than I should because of the great compression this gearbox gives and the fact that I'm using a Madbull 6.03mm tightbore barrel.

The only 2 problems is that the AIM gears are Infinite Torque-Up, so the ROF is going to be a tad slow because of the gear ratio of the gears. I'm running mine with an AMP T5000L High Torque motor which gave me 25 rps on Standard ratio gears, and gives me 16 rps on these gears. Also the gears sound really whiny, and is hard to adjust the motor height because of the way the gears sound.

The Advantage is that, the trigger response is tremendous.

The other problem is that the piston head is really shitty, and mine destroyed itself and got caught in the cylinder head locking the compression parts, making it sound like the piston itself was stripped after 10,000 rounds. However, I changed that, and now it's still great.

I'm really happy with this gearbox, and it is very much worth the pricetag. If I made another custom M4, this would be the gearbox I use.

ALSO!! A word of precaution, before I forget. The wiring out the gearbox for the battery is a small tamiya, I'm using a 9.6v 4200 mah Powerizer battery which is gigantic, but can squeeze into an M16 stock, but I did it by running a couple long connectors over the top of the battery, so that the two connectors are near the door to the stock for easy connecting and disconnecting, and also I did this way so I can leave the battery in the stock when charging it.
by John W. on 11/25/2009
"This is the best gearbox you can buy for the money. No shimming, greasing, or wiring needed. I dropped this in at op Fulda Gap and loved it. Works so great, I am afraid to take it apart again because its like a tm, the less you fool with it stock, the better it is.
by spencer a. on 04/16/2009
"Very good gear box. Really powerful. I had to file down around the mouth of my hop up to get it to fit right around the nozzle. It wouldn't shoot unless i did so. This gear box is great though.
by Marc P. on 04/11/2009
"solid gear box put it in dboy m4 with stock barrel, got it shooting over 438fps on average. hit a high of 448. deff gonna need a large type battery with gear box and g&p m120 motor i only get bout 3 1/2 hrs out of my matrix high output 8.4 1500mah batterys
by Amro S. on 01/27/2009
"Great box.. has a good shim job shoots and verry good air seal. I have had this box for a few weeks and it is good. it shoots at a High RPM and at a high FPS (580 barrel, matrix magnum, G&P hop-up.. 410FPS)
by Bo M. on 01/24/2009
"I have a 11.1v 4000 mah li poly battery that destroyed my first gearbox in under 2 minutes. My question is I want to know if this gearbox can handle the battery, and for how long. Please answer if you have this gearbox and know what you are talking about. Thank you.

Webmaster: I use the "brick" myself too. That battery really just require a gearbox that is reliable and has m120 spring or higher (so it doesn't spin too fast).

Surprisingly....the JG new black gearbox and this Matrix 8mm gearbox handle lipoly MUCH better than some of the $200~$300 gearboxes.
by George C. on 01/19/2009
"Absolutely great gearbox. worth every penny. The only problem I have with it is it is actually shooting at around 500 fps rather that what they say on the website. Its alright for me since I am a sniper and Jericho allows up to 550 for snipers though if you dont expect to be a sniper be careful with this one
by John c. on 01/04/2009
"rex m. if u want a lower fps you can just cut off a couple of coils until you get a low enough fps
by LOGAN P. on 12/16/2008
"Awesome gearbox. I found out it does come fully assemble in a high grade plastic bag in side a solid paper box with all the specs on it. Worth the $110 .