AK Upgrade Advise

[LucaGiorgio]

I have a CYMA CM.039C (http://www.taiwangun.com/en/electric/cnm-039c-full-metal?from=listing&campaign-id=14) but I am now looking to upgrade where necessary and where possible. Everything is currently the original parts other than the spring which was downgraded by my site to lower FPS due to it being too hot for full auto. But I want to change the spring too due to not knowing the quality or brand of the spring. I have also change my batteries and have some 1600MaH Stick batteries apposed to my standard 1200MaH.

I was wanting to change my gear box but wasn't sure whether to find a fully built V3 gearbox which I am struggling to find as I don't know which gearbox's are best or which I need or whether I should just upgrade the parts inside my current gearbox IE motor, spring ect.

I was thinking about changing the barrel possibly but wasn't sure of the quality of the standard one.

Things I am trying to improve on are Accuracy, Range, Rate Of Fire, (Not major but would love a beastly sounding motor when I'm firing) and finally the quality of the parts. Looking to keep FPS under 350 on .28's/.26's so I can keep full auto!

 

[Samurai]

Don't fix what's not broken. A Cyma will go for years just fine.

Change the connector to deans, use 7.4 lipo. Any other internal upgrades will give results so small, you won't notice or will just make things worse (this is more usual).

Clean the barrel regularly, don't use silicone anywhere, and use heavy, high quality BBs. That will give you the range and accuracy you need.

350 measured with 0.20 is the limit. Doesn't matter what fps it shoots with heavier BBs.

 

[Sitting Duck]

101% agree

350fps on 0.20's is most sites limit for auto guns....

you don't fix what isn't broken and to keep that gun at UK limit will mean it will never be a hose machine either

your spring will remain at m100 so max rof or response time will be aprox 20rps maybe a smidge more or she starts over-running or double firing

The setup inside is pretty damn good and very likely won't be able to be improved upon a great deal even by tech's

barrel's are pretty good for stock barrels, the box is sweet for such a modest priced gun

Later on if/when she plays up - THEN look to service and upgrade some bits n bobs is best advice

deans & clean barrel is really all you need to do I would say unless she is seriously under performing which I doubt

yes motor rewire mosfet options and AoE but tbh forget going nuts on high speed gearing replacing pistons n springs unless they are badly worn

you will have to stick at full stroke piston on m100 aprox spring no silly speeds so really stock internals are just fine to be honest

rest of stuff can wait until she really needs it - very likely you could make it perform worse if still running well

they are guns that need or warrant very little improvements coz they are that decent to start off with

(pains me to say that being a G&G M4 user)

 

[LucaGiorgio]

Thanks for your advise guys I'll leave it for now then, Dou not even recommend getting a good quality spring due to me not knowing what quality spring my site replaced mine with? Also can you recommend a good charger for a lipo and a good lipo brand? Not fussed about the price

 

[LucaGiorgio]

Also why does everyone get LiPo instead of the standard type? What's so good about them?

 

[Sitting Duck]

B6 type is about best and quick way of charging lipo's

Get a genuine one for not much more than a cheap clone B6

Look on hobbyking - the UK or EU site - be careful it is easy to order from Hong Kong and wait yonks

they do airsoft lipo's real cheap - probably the stick type about 166mm long if battery goes under dust cover is popular AK & MP5k lipo

deans or small tamiya options blah blah blah

20c or 25c rating is the norm - no lower

much cheaper at hobbyking - get a couple or even a few - wait a sec and they should offer you them at a reduced price but don't dismiss

(if it does either reboot or use another pc as it is a "one time offer" about 8-10% off)

 

[Sitting Duck]

Also why does everyone get LiPo instead of the standard type? What's so good about them?

modern, more powerful especially in upgraded guns, much more size/power options and cheaper from places like hobbyking

nimah's are not completely obselete - the 9.6v is still used as a stop gap between 7.4v lipo and 11.1v lipo

but in general a tweaked gun on a 7.4v lipo 25c will give plenty of kick

be careful lipo's if abused do pack a punch - they explode - yes they explode they are THAT powerful

don't worry they only do that if you are REALLY STUPID !!!!

i HAVE POSTED THIS LOADS I KNOW but still valid in case anybody thinks what the worst can happen.....

(Even the guys say they never seen one go like that but you gotta wonder - f*cking lucky it exploded AWAY from them...)

Even lipo short circuits - wow they do arc like f*ck the power is much more than nimah's

so best results a mosfet is wise but not immediate must if sticking to 7.4v 20c say

but the trigger switch can arc on high juice batteries so upgrades should include a mosfet if you start pushing things a bit

 

[Samurai]

Lipos are smaller, pack more juice and have better discharge rate. That means the motor can get any current it wants without voltage drop. If the voltage drops, the motor gets slower. So even if the nominal voltage of a 8.4V or 9.6V nimh is higher, when the motor works, it drops below 7V, while the lipo retains its 7+ Volts. Usually a 9.6V nimh gives about the same ROF of a 7.4 lipo.

A nimh must be charged full, every time, or it will loose from max capacity. Lipos can be charged anyway you want. Nicd batteries even have to be drained before each charging.

The spring only gives the output power. If you have the power, then that spring is fine. Bad quality springs loose their power quicker, but that means years.

 

[LucaGiorgio]

Thanks for both your guys help, I'm looking on that hobby king and the batteries say 25c-50c or 15c-20c none that are just like 20c does this matter?

EDIT: http://www.hobbyking.com/hobbyking/store/__67731__Turnigy_nano_tech_1200mAh_2s_25_50C_Lipo_AIRSOFT_Pack_T_Connector_.html

This one looks like it could be the one I need

 

[Sitting Duck]

Thanks for both your guys help, I'm looking on that hobby king and the batteries say 25c-50c or 15c-20c none that are just like 20c does this matter?

I was told that if a lipo says 15c to 25c take it as 15c not 20c

but tbh what are after:

http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idProduct=44626

make sure you click on flag - this was EU netherlands so no import duty and should arrive within a week

please double check ALL measurements - it is YOUR responsibility to do this do not sue me if it doesn't quite fit

it "should" do but again ANYTHING is YOUR responsibility to double check - don't get a battery that just squeezes in there

remember to add in some room for wires + balance lead - the tiny connector wire thingy on all lipos/lifes

others with deans prefitted:

http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idProduct=84545 from UK

http://www.hobbyking.co.uk/hobbyking/store/uh_viewItem.asp?idProduct=84544 from EU

jeeez I'm too helpful - have a looksey and ffs make sure you check it will all fit in

you buy from one location if possible - you can't add stuff from UK EU HK into same basket

coz you gotta checkout and pay for shipping from each country

hence lookey - see what is about and in stock, try n get it all from UK or EU

 

[Sitting Duck]

Thanks for both your guys help, I'm looking on that hobby king and the batteries say 25c-50c or 15c-20c none that are just like 20c does this matter?

EDIT: http://www.hobbyking.com/hobbyking/store/__67731__Turnigy_nano_tech_1200mAh_2s_25_50C_Lipo_AIRSOFT_Pack_T_Connector_.html

This one looks like it could be the one I need

UK remember not international = Hong Kong

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=84622

that lead is plenty long - could re-do it on a shorter lead

or maybe squeeze the longer one in perhaps

remember - get a few sets of dean connectors n heatshrink from fleabay - or least one male deans+shrink for gun itself

ffs - watch a few video's on fitting deans and cut wires ONE AT A TIME - SOLDER CUT OTHER WIRE

A lipo short will do arc welding on ya clips, make you $hit your pants and possible kill battery if not yourself too

 

[Samurai]

About the C rating:

It's the current it can supply without much voltage drop. Calculated from the capacity.

So let's take your 1200mah 25-50C battery. 25 is the current it can supply continuously, 50 is what it can give in a burst . You turn on the motor, it pushes 50 and in a second or two it drops to 20.

The current is calculated by multiplying the capacity with the C rating. 1200mAh x 25C = 30000 mA = 30A

Would an 1200mAh 15C battery be enough? It could give 18A continuously. For a few single shots it could be enough, but it would need to rest between shots to regain its burst rate.

An average, basic airsoft motor without much load needs at least 25A. High torque motors with higher load need over 100 Amps.

 

[vialli]

A guarder m90 took my cyma cm028 to around 330 fps the m100 was still around 360-370 from what I've been told guarder springs run hot.

 

[vialli]

A guarder m90 took my cyma cm028 to around 330 fps the m100 was still around 360-370 from what I've been told guarder springs run hot.