Cyma Cm.621 Upgrades

[Misery]

all in and now back together working a charm

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commened at same time poretty much no modding was necaserry i did have to reshim and ad an extra shim to the bottom of the sector as it was touching the sensor

only issue i have ran into is my mech safety with the new trigger the cut out where it latchs is deeper than the standard m4 one so the safety slips but tbh not to fussed on that one i can live with that lol

 

[RonLancs]

all in and now back together working a charm

View attachment 68550

I'd like to see the results as this is what I'm doing to my MP5 - £60 for the Perun is a steal imo.

 

[Misery]

i was replacing the standard cyma mosfet as it had burnt out on me bud fps is still same havent tried rps as ive set full auto to 3 round burst for now

 

[Sitting Duck]

Now the "fun" begins with learning the programming of it all

bit of a MENSA test getting ya round it at first

but you suss it - or there's always the reset/default option to fall back on

for when you totally screw up the settings

lmk when you get it play House of the Rising Sun

semi + 3 rnd burst

or

precocking tweaking

or

binary trigger bollox

reckon is what many fuck about with

but hopefully you sorted it all with some fancy features (and deans pre-fitted)

The safety issue might be the arm a tiny smidge too big/tight

that it catches and fails to rise 101% to fully engage & stop the trigger moving

might just require a light file/sanding of the arm/leg of safety to allow it slip into position

(had a similar thing with a SHS flat trigger, just a smidge tight fit/compatibility)

I mean the arm might not be rising or compatible with trigger

but not got it front of me but reckon it might be the safety arm & red trigger

might just be a little too snug that the arm is impeded at last bit that it slips under trigger

no biggy for you atm you might think

BUT IT WILL BE if you go to a site and the SAFETY does not function correctly

yeah you can programme it auto-semi-auto-semi etc...

but at some point you MUST sort that safety out

Don't matter if you know about it

others may not (like your own kids)

and things being what they are...

a non-working saftey - don't pull the trigger coz safe doesn't work...

yeah that won't work

it is like like a sign that says WET PAINT - don't touch

EVERYBODY tests it - YUP still wet paint

(it's dumb arse human nature to touch wet paint)

have a tinker but look to resolve that safety asap

 

[Misery]

Hahaha once i had calibrated it house of the rising sun was first thing i did looool

pre cocking and 3 round burst set triggers set as responsive as i like and thats it left as is

 

[Sitting Duck]

updated my previous reply...

look to resolve the safety issue though m8

apart from that - very very very well done squire

 

[RonLancs]

Hahaha once i had calibrated it house of the rising sun was first thing i did looool

pre cocking and 3 round burst set triggers set as responsive as i like and thats it left as is

Are you finished?  What's next Mwahaha

 

[Misery]

ill check back on that commenbt

updated my previous reply...

look to resolve the safety issue though m8

apart from that - very very very well done squire

the saftey issue to rectify just now id reckon id need to go back to stock trigger which i will do tonight till i can figure out how to extend the latch by about 2mm to take into account the deeper cut out on the new trigger for now im bout to stuff my face with cake as bday time for my wee girl

Are you finished?  What's next Mwahaha

with this one yes till it breaks then ill replace and upgrade ,future plans a m4 based dmr full metal the works lol buit wanna get a few skirmishes in with this and see what happens

if needs be @Sitting Duck i can program semi to safe and auto to what ever i want to but going bk to stoock is what i will be doing so its done properly no point coming this far just to fluff it at the end

 

[Misery]

@sitting duck sorted the safety out back to stock trigger for now lol

 

[Misery]

Are you finished?  What's next Mwahaha

i lied shes getting 13-1 gears and a rocket high torque motor....but in my defence it isnt a planned upgrade stepsons 516 shat a tooth on the spur gear so will give him my gearset and motor and well ya know the rest lol

 

[Adolf Hamster]

See this is how it begins.....

It'll be 13:1 short stroked before it ever hits the field

i lied shes getting 13-1 gears and a rocket high torque motor

fucking called it

 

[Misery]

tbf if step sons gun hadnt fecked i wouldnt be upgrading lol but didnt see point of buying a standard gear set when the 13-1 wasnt much more cost wise lol wife asked why i was buying a motor too was like well with giving him my gear set he needs a better motor so will give him mine and get another for myself worked a charm haha

 

[Adolf Hamster]

tbf if step sons gun hadnt fecked i wouldnt be upgrading lol but didnt see point of buying a standard gear set when the 13-1 wasnt much more cost wise lol wife asked why i was buying a motor too was like well with giving him my gear set he needs a better motor so will give him mine and get another for myself worked a charm haha

yeah i just couldn't miss the opportunity to point it out

don't worry, you're in good company, like i say some of us never shoot the same gun twice

 

[Sitting Duck]

snip - see update/status for mega waffle...

maybe get a set of 8mm bearings...

just in case the SHS Spur is a bit tight/chunky

then replace spur's top bushing with bearing

(leave bushing under spur)

that should give you a smidge more room to shim with & spin freely

if the 13:1 spur especially is so chunky it proves a little too snug/tight

I had to use a 8mm bearing, putting 13:1 ZCI/Big Dragon 13:1's in a 517 - modded for 13:1's

(just one bearing on top of spur as had virtually no room or play on spur)

left 5 x buhings as is, just needed a lower profile bearing on top of 13:1 spur

you might be OK, but my gut tells me it will be a little more snug on 13:1's

and if room inside is reduced - well you might find it a bit too snug/tight on bushings

You do seem to be rather unfortunate with these toy guns

are you related to this bloke by any chance...

 

[Misery]

will give it a read in a bit just woke up lol

i will see how it fits together before ordering bearing bushings bud as already spent 110 on parts lol and have also ordered paint to collect tomoz so can paint mine lol

edit: 8mm zci bearings ordered with rest of my stuff from ak2m4

 

[Sitting Duck]

HOPEFULLY that should do ya for a good while...

the RA motor should be ok in 621 - just avoid using AB

but if it does cause issues then keep 621 motor in ergh the 621

and drop the RA in the 516 & both guns should be much snappier

HOPEFULLY - your bad run of luck should lessen soon

(these toy guns can get a bit expensive with all these repairs & upgrades)

The point or trick is to only replace stuff when it breaks (or really needs stuff)

and meantime get these poxy fucking things running as efficiently as possible

if you are not careful you can sink a small fortune into them and still shoot shit or not at all

so fingers crossed this will fix & resolve stuff for a while now

 

[Misery]

@Sitting Duck bought ptfe tape yesterday done the seal which has sorted the cmpression when nozzle isnt fitted but as soon as nozzles fitted i have very little compression,any nozzle u recomened to replace it?

 

[RonLancs]

@Sitting Duck bought ptfe tape yesterday done the seal which has sorted the cmpression when nozzle isnt fitted but as soon as nozzles fitted i have very little compression,any nozzle u recomened to replace it?

Maybe try an SHS M4 21.4mm?  Try measuring the original nozzle first as the wrong nozzle may cause feeding issues. (sorry to jump in Duck) Also the new nozzle may be tight on the CYMA cylinder head which can also cause feeding issues as it cant move as freely. 

 

[Misery]

i dont have calipers to get an accurate measurement unfortunatly,yeah i thought that may be the case why i was asking first dont wanna spend more than i have to with how much ive thrown at this gun so far lol

 

[RonLancs]

i dont have calipers to get an accurate measurement unfortunatly,yeah i thought that may be the case why i was asking first dont wanna spend more than i have to with how much ive thrown at this gun so far lol

Maybe try a rough estimate with a ruler. To be honest you may just have to settle with stock nozzle as I know from experience most stock nozzles (without o-ring) will let a little air out. Even some o-ring nozzles do sometimes... I’d Chuck it all together and test FPS on .2’s and if it’s consistent leave it be. However we both know you’re pining for the perfect air seal and it’s another itch to scratch ?