Airsoft Replica EC-909 Advanced Edition (upgraded gearbox) - Black [E&C]

I’ve been using this replica for about two years as a DMR with several upgrades. Overall, it performs well in the DMR role and has good accuracy and consistency once tuned properly. However, the stock gearbox had a serious issue: after a lot of shots, it could get stuck in safe mode and would only work again if the gearbox was manually rotated. After addressing this problem and upgrading key components, the replica became much more reliable. With the right modifications, it’s a solid platform, but the factory gearbox definitely needed improvement. The body of the gun is perfect for better interior. I have also an issue, the iron sights should not placed on the factory replica, because the they scratch the paint, without flipping it up.

This replica comes with a sturdy metal frame and very good looks. The replica is simple to use so i would recommend this replica for someone who is looking into getting a DMR.

but the replica has some minor cons, i found that the iron sights couldn't be flipped up and would scrath the paint underneath. But the rail works good with red dot sights or other picatinny attachments

Gearbox died after 3 skirms.
Gearbox teeth got stripped with a 7.4 lipo.
Overall a good gun when it shoots. Accurate and precise. Friend is thabkfully able to repair it.
Just a bit unlucky with the gearbox.
Still for the price it's a beast!

If you are looking for a good DMR base replica, this is a great choice. The external build is very solid. The magazines, charging handle and stock have a bit of wobble, but it's not too bad. Can't complain about the externals. The gearbox is very good and comes with top-notch seal. However the hop-up may require attention.

If you are satisfied with the stock fps and are looking to use the gun as stock as possible, you should make sure the nub and bucking are properly installed and correctly interfacing with the hop unit, as me, and other people have gotten these guns with misaligned hopup setups. Otherwise, there isn't much to worry about.

If you are looking to upgrade this gun, I will go over all the stock parts and considerations you should make.

---Barrel and hop assembly---
-Barrel is a 6.04mm diameter 362mm length brass barrel. The window is rounded, therefore it's not suitable for mods like R-Hop. The barrel to cylinder radio is ideal for heavy bbs, even up to 0.45g. Using much lighter bbs may cause overvoluming, decrease shot energy and potentially impact accuracy.
-Bucking is a yellow translucent supple silicone bucking that has tight fit when installed. It has thickening to seal well against the hop up unit and barrel. The bucking meshes fine with the nozzle. It's an ok bucking, just needs a proper install.
-Hop nub is a flat hop nub. Snug fit in the hop unit, interfaces well with the arm. If you are planning to R-Hop, you don't need to replace it. For flat hop, it maybe be a little too thin and not push down far enough.
-Hop unit is a tough blue plastic rotary unit. Needs to be pushed onto the barrel just enough to put on the c-clip, or there may be issues. Do not force it on as far as possible.

---Cylinder, piston assemblies, nozzle--
-Cylinder head is made of brass, has 2 o-rings and thick rubber padding for angle of engagement. The padding can wiggle side to side, which might affect shot consistency. Despite that, it's inserted into the head so it won't get detached. Air-seal with the cylinder is amazing.
-Cylinder is not attracted to neodymium magnets. I would assume its aluminum. It's a perfectly fine cylinder, but if it's aluminum, it may be prone to scratching.
-Nozzle is brass, has 2 o-rings and seals well, but not perfectly with the cylinder head. Still very good for a stock gun.
-Piston head is aluminum, has 1 o-ring, and bearings. It seals incredibly well for a stock gun. No issues
-Piston is made of tough blue plastic, has a steel rack with 1 less pickup tooth for proper gear engagement. It's good, fits well in the gearbox rails.

---Tappet plate, tappet plate spring---
-Tappet plate is made of tough blue plastic. It holds the nozzle a bit loose. Though that isn't really a problem. It's made to work well with the sector chip of the sector gear.
-Tappet plate spring is nice and strong.

---Spring and spring guide---
-Spring depends on what fps you picked.
-Spring guide is steel and has bearings.

---Gears and motor---
-Stock shimming is mediocre, but nothing tragic.
-Sector gear has a sector chip. Angle of engagement with piston is fine.
-All gears are typical 18:1, but sector gear has more teeth to pull the longer V2.5 piston.
-Motor is a chaoli motor with quite a few winds per armature. However the motor cage magnets are very weak. Overall, the motor is not strong, but it should be fine if you use the stock main spring. If you upgrade the spring and/or shim poorly, the motor may overheat.

---Wiring and trigger---
-Wiring is tough, a simple mosfet is included. 11.1v batteries run well. 14.8v batteries work fine too. If you do use 14.8v, expect not to be eligible for warranty if something goes wrong (I'm not sure, but better be safe than sorry).
-Trigger has a heavier pull than an average AEG.
-The trigger unit does not have a microswitch. There are metal contacts.

---Gearbox shell, bearings---
-Gearbox shell is not attracted by neodymium magnets. Seems to be aluminum. Gearbox internals are greased only very lightly.
-Bearings (not bushings) are 8mm, not lubricated. You should lubricate your bearings.

Overall if you plan on modding, your focus should be on the hop unit. If you plan to use a stronger spring, then a more efficient, torquier motor and a good, powerful battery should be used. The bearings should be lubed before operation. You may also want to shim the rubber padding of the cylinder head to minimize movement.
This is a really nice replica, which needs just a few changes to become a great DMR.

I bought this replica about a month ago and I am here to share my opinion. Advantages, it is full metal replica (instead of front rails and stock) with very precise fits. The parts donot have any bad movement. The gearbox is well made, donot have any bad noise. The gun has mosfet and with a Lipo battery it has really good fire rate.
Disadvantages,the hopup chamber has some problem. First of all the factory hopup rubber isnot the best, and the spring on the barrel is week.
All in all, I used it in two games and I had dozens of kills from 40-60 meters away.
It has enough power to use 0.40bb to maximize your accuracy.