Intro to your CM020 Version 3 mechbox!

[yanhchan]

I finally got around to disassembling my Aftermath Ak47. I have some interesting findings to present.

The mechbox shell:
The shell seems well casted with no deformaties and the tolerances are mostly acceptable. Although there is a need to create clearence on the cyliderhead seating pins in order to fit aftermarket cylinder heads. The machine screws all have brown glue on top of them. It also seeped into the threads and makes the disassembly and reassembly process a major chore.

The gears:
The steel XYT gears show no signs of wear and appear to come well shimmed but poorly lubricated. However the grease used is rather thick and was probably applied with some type of squirt gun thus lacking even coating. The gears are able to handle up to an M120 without problems.

Anti Reversal Latch:
Probably one of the best damn Anti reversal latches I've ever seen its really well made, and the spring is extremely strong

Spring guide:
The spring guide is made of poor quality clear plastic, and has a washer at the back. It appear to be cracking after about 10 000 rounds.

Spring:
The spring appears deformed and bent.

The cylinder:
Brass cylinder shows oxydation and lack of grease therefore the airseal was rather poor.

Piston:
The polycarbonate piston has one steel tooth shows minimal wear after my last 3-4 games with this AK (Approx 10 000 rounds).

Piston head:
The piston head is a copy of the stock TM piston head with the exception that the spring isn't attached to the piston itself. It is rather difficult to remove the piston head from the piston due to the fact that the machine screw is attached to a piece of square nut. The O ring that comes with the piston head appears to have been damaged

Cylinder head:
The cylinder head is made of a strong resin plastic and has a rubber/foam back in order to absorb shock. The nozzle is brass.

Air nozzle:
The air nozzle is also made of a clear plastic and has no cracks but shows signs of friction wear.

Trappet plate:
Trappet plate is probably the only piece of plastic internal that appears acceptable. It is made of black plastic and is very flexiable.

Various small misc springs:
The various internal springs the mechbox comes with appear to be rather weak. Especially the spring that pulls the contact away from the terminal, it is easily deformed so be careful when you move it.

Electronics:
Well sodered but the fire group is missing one screw that screws it into the mechbox, this may not be the case for other guns. There's no grease or dirt on contacts, all contacts appear well made.

Motor:
The motor is quite strong and is able to pull an M120 while keeping a fair ROF using 8.4V. In addition I am able to turn an M110 using a 7.2V.


Hop up chamber & Hop up

Weirdest freaking thing I've seen in my life, there's no hop up rubber but its just a piece of plastic that the BB comes into contact with that provides the hop up. (Should be replaced immidiately along with a new barrel)


Recommended upgrades

Metal Bushings (should be done ASAP)
Metal Spring guide
cylinder head, piston head, air nozzle
Spring

*Note if you plan on upgrading to a brass or metal cylinder head you may need to sand the holes of the cylinder in order for the seating pins to fit into the cylinder.

**I have used 6mm bushings and they seem to sit a little loose so you might want to apply some epoxy to the holes before you fit yours into the mechbox.


***What I did to my gun***
I installed the following

Modify AK bore up cylinder set (from SAFX 50 bucks+shipping)
Guarder spring guide (20 from jugglez)
Modify 6mm Bushings (15 from Jugglez)
Madbull poly piston
Madbull M110 spring (14 from Jugglez)


***with all the upgrades my gun can now shoot thorough the bottom of a pop can!***

[Firas]

Very informative, thanks! I am actually picking one up today for my father, so it's good to know

[Kokanee]

Regarding the hopup, are the mounting holes/screws a standard TM hopup present, and as such is it a drop-in operation to replace the hop/barrel assembly w/ a standard TM one?

[yanhchan]

Yeah you can drop in a new Hop up unit by TM/Element/Prowin easily. I think you need a new barrel to go with the new hop up though.


Here's a link to how it looks disassembled

http://acmdavao.proboards44.com/inde...ead=1144316044