ICS M4A1 upper gearboxes

[ronburgundy__]

I want a 2 peice gearbox

[spleinmuncher]

If you fix up all of the crappy internals ICS puts into their guns, you have a gun with a rock solid GB and the convience of the Split GB to boot. Anyway, it would probably be wise to get a piston and a piston head simultaneously (make sure its not an aluminum piston though -- even the ICS Upper GB is not that tough. Also, it mite be good to get a ported piston head). Spring guide, no need for it to match anything in the box -- just make sure its a V2. Same goes for the tappet plate. Spring is anything you want.

[Aaron886]

oh, if i do this, i'll 90% likely go ground up. piston head would be polycarb, ported i spose. tappet? anything not ICS. and a *cough120cough*

 

 

 

i already bought the gun, pillow.

[SlvrDragon50]

You really dont need to replace the tappet plate until it breaks but you can if you want. I accidently bent mine so Im replacing mine with a guarder one although I think im going to try the element ones next.

[Aaron886]

cool. i'll be pre-emptive anyhow if i can find a good ish deal.

[spleinmuncher]

Since you are building it from scratch, you should avoid the ICS tappets. Beyond that, get a Systema, or, if you can get your hands on them, one of these badboys:

 

ok, here is what I did on the tappet plate yesterday:

 

I twist it this way and then twist it back....here is the result.

 

The plastic didn`t turn white!!

After doing it 6 times in the same tappet plate, it breaks finally.....

 

and I tried the red hop up chamber in the CM-028 also, the result is pretty good!!

It increases the fps a little bit, I chronoed the stock 028 at 0.76J with 0.25g bb, after installing the red-hop-up, an old src hop-up bucking and a TM original barrel, it shoots at 0.85-0.87J constantly.

 

Here is some picture I took:

 

the top one is a original CM-028 front end, the lower one is upgraded with the red-hop-up.

 

I will test the gears and pistons and all other internal parts in the same CM-028 tomorrow.

<{POST_SNAPBACK}>

 

Also, it mite not be a bad idea to get a replacement for the ICS tappet in your other GB, and when that one breaks, you can replace it rite away. The Split GB is designed so beautifully that you can replace that broken Tappet plate in the field. Its that quick.

[SlvrDragon50]

You can but its not too smart, drop a piece.. you are dead. Unless you bring a work mat in your load out x.x

[spleinmuncher]

OR take out one of those plates in your plate carrier

[Aaron886]

rofl.

[Aaron886]

it's here, and it's beautiful.

[spleinmuncher]

You put it together? Excellent!

[Aaron886]

hehe... again mistaken, i meant the gun finally came. it's excellent, by the way, extremely impressive accuracy, rate of fire, heft is considerable with all that gorgeous metal. simply incredible.

 

 

one problem, however, i've had this maybe twice... i've fired some rough shots on full while testing, frequent radically different length bursts. then, i think i can almost feel that the feel of the cycle is different... like a timing issue (how the heck would that be possible? it's GEARS!) edit- i read tommygun's post on "timing..." thanks a ton.. then all of a sudden, i'll get a short grinding noise (somehow i've never experienced this at the middle of a burst, it's always the end. it doesnt STOP my shooting, it seems to be a response of the gun, not vice versa), and a BB will fall short. it's a little scary, i've opened the split gearbox (simply incredible design, easy to access, sturdy, strong...), and checked all the gears for signs of scratching or excessive wear that might mean grinding gears... but i see nothing. what of the piston i can see is also clear. (also tested the strenght of the gear metal on sector and spur gears, feels good) the bevel looks ok down in the depths of the lower box, and i don't imagine it's the pinion, unless the motor's misadjusted (how to tell?). Maybe it's the anti reversal latch? would that even factor in on auto? (these are bursts, remember.) never a problem on semi whatsoever.

 

now knowing what i just read from tommygun, i'm leaning toward tappet problem, since ICS tappet plates are reportedly ######...

 

 

 

 

i'm not sure as to the precision of the barrel, but at about 100 ft, i can consistently hit a soda can on full auto with 0.25g BBs... any burst will put about 75% of its BB's in a 5 inch circular area. anyway, any idea as to the problem i outlined above?

[Aaron886]

...

 

 

fired more rounds through it... about 900, with 0 problems this time...

[spleinmuncher]

Shimming? Maybe the shims are loose somewhere, and while firing, one of the gears tilts too much, thus creating that sound. Also, it could be something with the cutoff lever alignment, check that as well. Finally, check the motor, too.

[pillow_pwnage]

Check -

 

- motor height

 

- shimming

 

ICS shimming is known to be on the shoddy side, I'd look more into it as the culprit.

[Aaron886]

ahh. will do. i havent really looked into the shims yet, so we'll see.

 

 

however, i really don't know how to check motor height...

[Aaron886]

ok, shimming seems fine, just a touch of play on the spur... i don't think it can fully contact either gear in any way but the teeth... so it's not shimming.

[Aaron886]

...