Jump to content

CYMA CM.028 Examined


Rattler

Recommended Posts

The CYMA CM.028 AK-47 Examined,

gunsincse.jpg

 

 

 

First I will start out with the body,

 

Very sturdy, high metal contet and good wood detail, even better wood than the marui.

33460053.jpg

 

First, to take apart the gun you must remove the top battery cover, then remove the little screw on the plate covering the gearbox, then remove the little hop up LEVER ONLY, held down by a small black screw. Then, remove the 4 screws on the bottom of the lower receiver and remove the front half of the gun. Note: When pulling the front half out, it will stop before it is fully out, just tilt the front downwards and it will pop right out.

NOTE: Be careful that the little nuts in the front section don't fall out, never to be seen again.

33460047.jpg

 

 

Then, remove the selector switch cover,

33460038.jpg

 

Then remove the screw holding the switch and the switch slides right off,

33460036.jpg

 

 

Next, remove the handgrip,

33460043.jpg

 

33460041.jpg

 

 

Also, when you remove the front half, there is a little metal piece, it slides onto to posts on the sides with the lip on the UPWARDS side facing the opening.

33460044-1.jpg

Link to post
Share on other sites

Next we get to the gearbox,

The gearbox appears very sturdy and does very well with the m100 spring in it (stock), I put about 13,000 rounds through mine without 1 single problem. The gears are sturdy and seem very durable. Also there is some debate on the compression, I was going to replace the o-ring in mine because I had heard about the bad compression and when I tested it, it turned out very very good and I ended up not replacing it.

 

33460001.jpg

 

The bottom assembly,

33460003.jpg

 

The piston, seems ok,

33460010.jpg

 

M100 spring (stock)

33460008.jpg

 

Piston head,

33460011.jpg

 

Spring guide,

33460020.jpg

 

33460021.jpg

 

Tappet plate,

33460023.jpg

 

33460024.jpg

 

Anti-reversal latch,

33460025.jpg

Link to post
Share on other sites

Gearbox parts,

 

33460029.jpg

 

33460028.jpg

 

Overall, a very sturdy decent gun, there are parts however that could be better like the crappy wiring, the wiring in this gun is absouletly HORRIBLE and I reccoment putting in something like 18AWG.

The nozzle, the nozzle comes too big in some of the versions of the .028 and will misfeed a lot.

 

The hop-up, however the hop-up works great it is not marui compatible thus it cannot take a better tightbore barrel.

 

The barrel, The barrel is an aluminum stock (6.08mm I believe) and shoots ok but it would be better to upgrade it.

 

The bushings, like most mpegs, the gun has plastic bushings but they hold up pretty good.

 

Shimming, again, like all mpegs, needs re-shimming.

 

Yes, there are a few cons but there are many more pros than cons such as,

 

High metal content

Great looks

durable

accurate

fast

good gears

reliable

M100 stock spring with a gearbox than can handle it well

Easy dissassembly

 

Any questions? reply or feel free to PM me.

Link to post
Share on other sites

Performance,

NO BS RESULTS, I personally took these tests.

Chrono'd (in chronor, no estimate) 292fps constant

Range, 80-100 feet ACCURATELY, 150+ feet total

Rate of Fire, 750-820 rounds per minute

Battery life, approximately 4 hours

 

 

Metal parts include, muzzle/front sight, barrel, mock cleaning rod, front sling mount, click adjustable rear sight, bolt, upper receiver cover, trigger guard, trigger, selector switch, rear sling mount and gas release chamber.

 

I just used it in our states larget airsoft event as my primary going against upgraded TM, CA, Star etc and I held in just as long as anybody else and was holding the front line without one flaw or gun failure.

 

 

Rattle

Link to post
Share on other sites

Very nice. Okay if I were to want to upgrade the CM028 to around 1J what would I need. I'm definatly going to get metal bushings, a new hop-up, and barrel. What else would I need to make it more reliable? I definatly need a spring guide as the stock one is full of bubbles. Is the spring guide V3? Would changing out the cylinder, piston, and cylinder-head help at all? The wiring in mine wasn't too bad. Just a bit worse than my old ICS MP5. That is an easy one to fix. The barrel's length is 455mm? Last, is the threading -14mm?

Thanks :)

Link to post
Share on other sites

If you have the money, yes replacing all those parts would make a big defference and then you could put in a 1J spring (cant say the spring name). Your gun would last as long as any TM or CA. Yes, the gearbox is a V3. Changing the cylinder (and head) and piston and all wouldnt make too big of difference but would last longer than stock. The wiring, I reccoment AWG 18 high strand. Yes, just making sure, you would need the following parts.

Metal bushings

re-shim (highly reccomended but not required)

new spring guide

new tightbore barrel

 

Also it would be good to replace the full compression system just to make it the ultimate,

Cylinder

Cylinder head

Piston

Piston head

Nozzle

 

Not sure on the threading and I will check the length of the inner barrel but it is normal AK length.

 

 

Does it come with a battery? Does the s version run off of a stick battery? What kind of mag xomes with it and how many? Mags TM compatible? Thanks.

Yes, the full stock comes with a mini connector battery, charger, 1 mag (100% TM compatible), sling, and some bb's.

 

The folding stock (S version) comes with the same accesories but uses a stick battery. I reccoment the full stock because the folding stock breaks the locks on the stock so it swings loosely after a short time but if you are careful, it is all about what you prefer.

 

Hope I helped,

Rattle

Link to post
Share on other sites

Thanks.

I was look on Gunner's and I found I could get:

Silence Cylinder head set for Ver.3 gear box $13

V3 Bearing Spring Guide $9.50

6mm Steal Bushings $7

Element AK Hop-up chamber $13

(Already have several Systema hop packings)

Classic Army 463mm Tightbore $22

AKM Wood kit $52

Element AK Metal Body.

Element AK Ribbed Top Cover $22

Element AKM Steel Compensator $7

Total $173.50 + S&H

Add that to my CM028 w/seven standard mags and you have a fierce weapon, no? :D

Anything else I might want to get? Like a tappet plate and nozzle? I hear the CYMA has a nonstandard one. And what about piston? Mine looked pretty good when I disassemble it a week ago. O-ring was *beep* though. Replaced it and got a 15FPS jump.

Thanks again! :)

Link to post
Share on other sites

yes, replace the nozzle, the stock one is junk. The piston is ok but if you want it wouldnt hurt to replace it. You will have one mean gun when you add all the upgrades you have listed + a new nozzle and a powerful spring.

 

 

Edit: Also you could put in an eg1000 motor with the metal bushings, aslo try to get it re-shimmed to increase the life of the gears.

Link to post
Share on other sites

Are the gears TM motor compatible? I don't want to mess with the spring right now. The stock one is good for 320FPS when you have good compression. Not too worried about the motor either. I believe I will have to replace the tappet plate if I get a new nozzle.

I'm also going to have to get some black paint to cover the silverish bolt on it to get that AKM look. Would it look bad if I left the standard top cover on it? I know the AKM uses a ribbed cover but, that is $22 extra dollars I can use for other stuff. (I'm weird that way. Got to have my stuff accurate to the RS) :P

Link to post
Share on other sites

TM motor compatible? you mean can they take the motors speed? if so yes they can.

 

Wow, 320fps, I guess I need to replace my o-ring, the compression in mine seems fine so far.

 

The tappet plate should take any AK nozzle.

 

As for the paint, its up to you, I am not too familiar with the M model so I could not shoot for accuracy on a paint job for it. Main thing is keep it accurate.

 

You are gonna have a real sweet gun there when you are done, if you do paint it, send me some pictures and chronies with the new parts.

 

 

Rattler

Link to post
Share on other sites

The motor part is about the gears meshing. For example ICS gearsets won't take a Marui or Systema motor. The gears do not mesh. The whole tappet plate thing is from a older thread about the CYMA's having a unique tappet that only take's their nozzle. But for $16 for new nozzle and plate I don't really care.

I will be sweet if I decide to get these parts(if being how much money I get at my Birthday party tomorrow ;) $60 already. Need probably $250 for all this stuff with shipping) The total cost of the CM028, all of the reinforcing parts, seven mags and AKM conversion kit will cost around the same as a CA gun with a battery ;) (I payed $120 for my CM028 w/seven mags. Yeah for sales!!!)

Link to post
Share on other sites

Yes, it is TM compatible in meshing. With all those upgrades it will be as good as if not better than a CA so I wouldnt worry about that. The tappet plate (at lease on the newer ones) is supposed to accept and AK nozzle, I am getting a new one Sunday so I will let you know how it works.

Link to post
Share on other sites
Yes, it is TM compatible in meshing. With all those upgrades it will be as good as if not better than a CA so I wouldnt worry about that. The tappet plate (at lease on the newer ones) is supposed to accept and AK nozzle, I am getting a new one Sunday so I will let you know how it works.

I wasn't worrying about it. ;) I was pointing out that I can have a custom AKM for the cost of a run of the mill CA Armashitte.

Link to post
Share on other sites

wow nice guide mate :D

 

are you UK based?? becouse ive ordered my gun from gunner airsoft and i was wondering if anyone knows roughly how long it would take to get here?? i chose the cheaper shipping becouse ive been told that its less likely to incur customs charges.

 

thanks

 

ali

Link to post
Share on other sites

Is there a fuse? I didn't see one. I'm having a bit of trouble with my UTG "paratrooper" not firing. I'm pretty sure it has to do with the wiring. I have checked the motor connections and the battery, but everything looks good there. The motor isn't trying to move, so I figure that it is the wiring. I'd rather not take anything apart as the gun is still under warranty and taking the gun apart and not being able to put it back together again would be a problem.

Link to post
Share on other sites

Thanks, great guide I followed It and disassembled my AK pretty quickly!

 

Anyway I was just wondering where exactly is the O-ring in this gun? I have searched but I couldn't really find anything telling me where it actually is?

 

I have also heard it can be damaged by removing the two parts of the gun - is this true?

 

Thanks for the help!

 

EDIT: Not the o-ring around the piston...

Link to post
Share on other sites
  • 1 month later...
I was referring to the hop up rubber and was tried  :P

 

it's in that white (or black as in the pic below) doodad that goes with the front half of the 028 when you disassemble it.

you have to remove two screws attaching the hopup unit to the front trunnion and then you have to remove five screws to crack open the front trunnion. here's a pic of the hopup:

hopupvx2.gif

 

you also have to remove two small screws to get the hopup bucking out.

cheers, :)

 

zT

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and the use of session cookies.