Gun not firing

[WDM83]

Hi,

In need of some advice, i have an ICS M4 ([SIZE=13.44px]ICS-141) i bought it about 5 years ago and it had about a year of use before i stopped playing.  Have started playing again and on the first outing the gun stopped working after about an hours game play.  Pull the trigger and absolutely nothing happened.  I bought brand new 8.4 nimh batteries and tried them in a friends gun which ran fine so the batteries are good.  On taking the upper and lower apart the piston spring released, i would then need to lower the motor in order to move the gears in the correct position to refit the upper and lower.  It would then shoot for a little while (maybe 20 bb's) before locking up again.  Not really sure what the problem is, if i run the gun without the piston in the gear box runs fine but as soon as the piston is back in it will lock up again.  The gun is completely stock and i can't see any obvious damage to the gearbox or piston teeth.[/SIZE]

[SIZE=13.44px]Any ideas what could be causing this?  Has the motor just run out of oomph?[/SIZE]

[SIZE=13.44px]Thanks in Advance[/SIZE]

 

[Sitting Duck]

From the sounds of it, it sounds like the motor is built up with carbon

or you have a resistance issue from not so sound connection

Something is causing resistance or bad solid connection to motor

carbon can build up with long term use and higher juice

but you have been using 8.4v ???

I mean ICS have a video about using a schottky diode across motor

to help reduce spikes and carbon build up - but really no other motors suggest this

(though electrical geeks will say it helps)

Have you got an Active Breaking mosfet in there - doubt it but if fitted this can cause carbon build up

ICS motors can crap out, Lord Metile or whatever had to have his ICS motor replaced in his M4

(I've hardly used mine so they are in mint condition)

You don't "lower the motor" - you just cycle gun in semi in semi to get no gears showing

then refit top half of box

The shimming is not that bad in ICS's, the motor angle is a bit out imho but shimming is OK

bit loose, but bevel shimming & pinion height was not far off on mine when I checked it

So you should not be lowering the motor as you say, or was that an expression of speech ???

you shouldn't need to touch the height tbh, just cycle so no piston gears show on sector....

What might be worth a go is examine the motor as is - no stripping

you should be able to see the spindle or commutator where brushes contact

now you "might" be able to clean up the blacked commutator a bit

using say a fiberglass pen.....

https://www.ebay.co.uk/itm/3pc-Scratch-Brush-Set-Pen-Style-Fibreglass-Brass-Steel-Rust-Dirt-Removal/302687236068?epid=11011557215&hash=item467990afe4:g:t0AAAOSwLdBaO7Vs

jam that in, rotate motor by hand and clean up some of the carbon

blow it out loads and retry the motor.....

sometimes you can get a winding blow

there are three windings on the armature of motor inside

sometimes a wire winding can blow and that winding is dead

in this case the motor stalls sometimes coz it can get moving from still

often in use it will keep rotating (poorly) once it spins

but from still with a dead winding it will refuse to start

other times you can get a black resistant carbon build up

or a short/bridge in the tiny fine line breaks between the commutator sections....

View attachment 34878

tbh most people don't do much motor servicing

at like £30 for a better motor most will just replace stock motors with shs ht or ra ht motor

https://www.ak2m4.co.uk/internal-parts/motors-parts/ra-high-torque-motor-long

But the ICS 2000 ferrite motors are pretty decent for a stock motor, bit snappier than most stock ferrites

or you might have the neodym motor 3000 if you got strong chrome/silver magnets

I'm stabbing at the motor coz it cycles OK for a while

it could be as dry inside gearbox as a bone or other stuff

but I'm leaning towards motor with what you desrribed

but still a guess all the same atm

hence get some firberglass pencil and give a quick clean without stripping motor

the motor is pretty decent, but has o-ring pinion so not easy to strip down

need a motor puller tool really and hence a lot of people say sod buy a new motor

if it has silver magnets then keep hold of it no matter what

neodym magnets are very strong and worth taking a bit of time rebuilding

(or flogg on if you can't be ar$ed, a dead neodym motor or  can is worth say a tenner perhaps)

There are other possibles - sometimes the selector plate has a copper sleeve that bridges the switch prongs

some china makes use this type of switch like Cyma, SRC & others - SRC is Taiwan but same meat different gravy

but pretty sure ICS like G&G do not have this copper sleeve selector plate/switch so it won't be that....

So yeah kinda thinking check wiring for good sound connections, then see if you can clean up motor with pen

that should help imho, or you got a chipped tooth or something dodgy in drivechain/gears or other stuff inside box

 

[WDM83]

Thanks for the detailed reply that's very useful.  I have one of the those fibre pens so will give it a go cleaning up the contacts.  When i said dropping the motor it was un doing to 2 screws at the bottom of the handle as if it was going to replace the motor not the motor height screw in the middle.  That was the way i found i could reset the gears so the flat section was on top as per your first picture. 

 

[Sitting Duck]

Thanks for the detailed reply that's very useful.  I have one of the those fibre pens so will give it a go cleaning up the contacts.  When i said dropping the motor it was un doing to 2 screws at the bottom of the handle as if it was going to replace the motor not the motor height screw in the middle.  That was the way i found i could reset the gears so the flat section was on top as per your first picture. 

Click to shrink...

Well you just cycle the gun on semi or auto to arrive at that point

heck you can pop the AR Latch and you should be able to move the gears/motor back into position

I mean if you got a silver magnet/neodym motor it will be harder to turn by hand

but more than one way to skin a cat - the biggest resistance is the main spring and a tiny bit by tappet plate

both are out of the way as you popped the top half of gearbox or upper receiver with it all still in

you should be able to jam the pen in there to clean up the commutator, without dismantling the motor

clean it up a bit, give it a really good blow out and should hopefully help with a cleaner commutator

fingers crossed you can squeeze a bit more fun out of your gun without too much fuss/expense

check wires and connections, all joints/connections can come loose

check the motor leads - they have 2.8mm connectors which can become loose fitting and cause erratic problems

basically - check all bits n bobs are sound connections

one of them motor connectors could be loose - LIGHTLY crimp them in some pliers but only lightly ffs

just enough so they connect snuggly

 

[WDM83]

Just to give an update, having cleaned all the contacts on the motor it is still the same.  Now the gearbox tries to cycle once but doesn't complete so no BB is fired and i need to split the upper and lower to release the spring and the chambered BB.  Going to go ahead and replace the motor and see what happens

 

[Sitting Duck]

The motor could be suspect & a replacement could be a worthy improvement

BUT as I briefly mentioned the box could be as dray as a bone after all those years

so it might be in dire need of a service & re-grease - especially on gears/axles

If motor/gun/wiring gets hot then it needs further investigation and likely a strip down/service

personally I'd probably would have done both strip down & upgrade etc....

checking all parts for wear/damage and any stress/friction

but depends on your ability, but the split design helps in stripping down

still need to apply care & common sense of course - lots of bits n bobs for new tech to worry about

BUT ICS do some useful tutorials about stripping down their stuff

so you can decide if you attempt this if the need arises

Think the box should be ok for wear/damage but could need a regrease though if it is very old and grease degraded etc...

 

[WDM83]

I have now replaced the motor with a SHS High Torque one and whilst i was at it replaced the stock cables with an Element wiring kit and cleaned and regreased the gearbox while it was all apart.  Quick test fire and it seems to be ok, will test again in the next few days with some BB's in the mag to check all is ok.  Thanks again Sitting Duck for all the assistance