Cracked Mechbox...KWA M4A1

G.I. Joel · December 2nd, 2008, 23:50

I have a cracked mechbox Shell in my KWA M4...What the hell could have broken this badly...I have read a thread about a sector gear shearing, but I wasnt using a Lipo...dont own one.
Just putting this out there as a warning to others maybe their casting procedure is less than great?

Its a tank and still shoots well and snipes well. I broke my hop-up adj. wheel and was to replace it...now I think I have more important things to do.
If anyone had dealings with KWA about warranty/tech problems lemme know.Thanks

KND · December 2nd, 2008, 23:51

huh ! you might get a lemon as mine ! lol :banghead:

arman · December 2nd, 2008, 23:55

whats a warranty when it comes to airsoft??

KND · December 3rd, 2008, 00:03

KWA actually give warranty to you, they would sent you a new shell but it's not worst of money and I kinda hate when they ask for my master card first before shipping.

Quote:

Originally Posted by arman

whats a warranty when it comes to airsoft??

ShelledPants · December 3rd, 2008, 00:05

JB Weld?

lupo · December 3rd, 2008, 00:08

I tried to deal with KWA usa on some parts but got no where. I tried ordering a set of bearings from them , thier shopping cart system listed instock but infact wasent. The sales rep got back to me after a week said they had just moved locations but they would get some out to me as soon as the next shipment was in. After a month I sent a request about the bearings , they had a shipment come in and were all sold out again. So In the end I sourced the bearings from 2 different companies , because KWA uses 8/9mm bearings and it took about 2 weeks (with one set coming from HK).
2 days after the parts arrived and the aeg was fixed , KWA emailed saying they had the parts in stock. This was 3 months after my original request for BEARINGS! one of the cheapest most common part in an AEG.
My expierience may be different from other peoples but somehow I doubt it. Seriously though , good luck with getting some warranty parts from them , I hope it works out for you.

G.I. Joel · December 3rd, 2008, 00:22

Quote:

Originally Posted by KND

KWA actually give warranty to you, they would sent you a new shell but it's not worst of money and I kinda hate when they ask for my master card first before shipping.

Thats what I was afraid of. The Lady I delt with there was nice and very helpfull on the phone, but From what you all are saying is that its gonna be an uphill battle...If I got a new Shell @ 0$ cost to me and I guess I'd pay for shipping, I shouldn't complain. I just hope that's the way they see it.
thanks for your thoughts.
Joel

Styrak · December 3rd, 2008, 00:28

It's a V2. It's bound to break in that location when it's shooting what, 400+ fps stock?

Buy a new, better mechbox shell.

Crunchmeister · December 3rd, 2008, 00:39

Quote:

Originally Posted by Styrak

It's a V2. It's bound to break in that location when it's shooting what, 400+ fps stock?

Buy a new, better mechbox shell.

Unfortunately, Styrak is right. That's the eventual fate of any V2 box shooting that hot. A reinforced shell will last significantly longer, so that's probably your best bet.

BORDENSNIPER · December 3rd, 2008, 02:36

were u running it stock?

i know the aluminum piston head is a POS, im chaning it out for polycarb and sorbo piston.

LUTNIT · December 3rd, 2008, 05:45

LiPo would not have made a difference. Mechboxes breaking has nothing to do with batteries. Life of a mechbox is usually measured in shots fired.

m102404 · December 3rd, 2008, 10:38

How did the hopup adjustment wheel break? Was it from closing the upper and lower receiver halves...or some other way?

I've seen a couple of the KWA M4's and the mechbox shells have been very decent to date.

While you might have gotten a lemon...I sort of doubt it (no offense).

If you peruse back through the threads a couple of years ago...there's plenty of info on what causes mechbox breakages. High fps (i.e. 400+fps w/ 0.20s), high ROF, aluminum pistons, aluminum piston head, cold temperatures, "stock" shells vs "reinforced" shells, v2 vs. v3, etc...

From the above items...the KWA has a lot of the downsides. The rifle shoots about 420fps stock, it has an aluminum piston head (which is not thread loctighted from the factory...and I've seen the results of one coming loose), it is geared for high speed ROFs ("LiPo ready" sales pitch, right?)...and it's winter (but that's not KWA's fault

)

Do:
- change out the piston head to a polycarbonate piston head. I like the systema silent head sets...they're cool.
- downgrade the spring to a M100 (that'll put you in the mid-high 300's...around 360-370fps, which is nice)...or a M110 if you want to be just around 400 +/-10fps.
- let your rifle "warm up" to room temperature...that means getting to games early if your rifle has been in the cold trunk for a while (getting to games early is a good thing anyways).
- check the shimming in any "new" rifle....be it BNIB or "like new/only fielded once" used. KWA's are very nice...BNIB.

Don't:
- go for high ROF setups...unless you're willing to bust mechboxes (that's just life). Writing letters with a solid stream of BBs is fun though....
- pull your rifle out cold, slap a battery in it and rip off a burst
- be surprised when toys break...and there's no practical warranty for it...(i.e. you're not buying a TV from Best Buy or Future Shop).

On a positive note - almost any standard or reinforced V2 mechbox shell will work as a replacement. I'm assuming that you're looking for a "front wired" one. You could try to reuse the un-damaged parts from the KWA mechbox...but it might be less trouble and easier to buy a complete new one. You will need to reuse the KWA M4 nozzle. However, if you're replacing both the hopup and the mechbox, it might be easier to switch over to a "normal" one that doesn't have the notches and slots that the KWA one has (don't know for certain...none of the ones I've handled has had a broken nozzle/upper-hopup).

Best of luck,

Tys

Midgetkid · December 3rd, 2008, 11:43

Quote:

- check the shimming in any "new" rifle....be it BNIB or "like new/only fielded once" used. KWA's are very nice...BNIB

KWA rifles do no have shims, they have precision gears that dont need shims to line up

ShelledPants · December 3rd, 2008, 11:55

Quote:

Originally Posted by Midgetkid

KWA rifles do no have shims, they have precision gears that dont need shims to line up

That doesn't mean that a KWA rifle didn't have loose tolerances and need a shim or two.

m102404 · December 3rd, 2008, 11:59

Two of the KWA's that I've come across needed a ship on the sector gear, and almost every KWA (7-8 to date) that I've worked on had lateral play in the bevel gear. Was it going to lead to a catastrophic failure...can't say 100% for certain. Was it nice to know that things were setup nicely...100% for certain.

For the ones that needed shimming...it may have been from how far the bearings were pressed into the mechbox shells...it may have been from variances in the gears or the bearings themselves. From my determination, they needed reshimming (and I do know from feedback from some of the owners that their rifles are still going strong).

But, most certainly, they were all quite nicely setup right out of the box (i.e. worlds ahead of junkers like Dboys...or even nice setups with nice components like G&P complete boxes).

You can take the most precisely machined piece of anything and put it into an assembly, where upon it's precision and the ultimate end result is immediately dependant on much more than any one components precision. Factors such as QC and tolerance stacking come into play.

Certainly good enough...is good enough. But there's always better...

My statement to the effect that checking the shimming of any AEG (new or used) is a good idea stands (but you are certainly free and most welcome to disagree

!).

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December 2nd, 2008, 23:51	#2
KND * AV revoked * Trader rating Join Date: Apr 2008 Location: Downtown Montreal	huh ! you might get a lemon as mine ! lol :banghead: __________________

December 2nd, 2008, 23:55	#3
arman Trader rating Join Date: Nov 2006 Location: Windsor, Ont.	whats a warranty when it comes to airsoft?? __________________ playing with my kid!

December 3rd, 2008, 00:05	#5
ShelledPants Trader rating Join Date: Feb 2008 Location: Toronto, On	JB Weld? __________________ Ár skal r?*sa, sá er annars vill fé eða fjör hafa. Sjaldan liggjandi úlfur lær um getur né sofandi maður sigur.

December 3rd, 2008, 00:08	#6
lupo Trader rating Join Date: Dec 2001 Location: vancouver	I tried to deal with KWA usa on some parts but got no where. I tried ordering a set of bearings from them , thier shopping cart system listed instock but infact wasent. The sales rep got back to me after a week said they had just moved locations but they would get some out to me as soon as the next shipment was in. After a month I sent a request about the bearings , they had a shipment come in and were all sold out again. So In the end I sourced the bearings from 2 different companies , because KWA uses 8/9mm bearings and it took about 2 weeks (with one set coming from HK). 2 days after the parts arrived and the aeg was fixed , KWA emailed saying they had the parts in stock. This was 3 months after my original request for BEARINGS! one of the cheapest most common part in an AEG. My expierience may be different from other peoples but somehow I doubt it. Seriously though , good luck with getting some warranty parts from them , I hope it works out for you.

December 3rd, 2008, 00:28	#8
Styrak Trader rating Join Date: Jan 2007 Location: Saskatoon, SK	It's a V2. It's bound to break in that location when it's shooting what, 400+ fps stock? Buy a new, better mechbox shell. __________________ Airsoft Sales and Repair/Upgrade Services

December 3rd, 2008, 02:36	#10
BORDENSNIPER Trader rating Join Date: Feb 2005	were u running it stock? i know the aluminum piston head is a POS, im chaning it out for polycarb and sorbo piston.

December 3rd, 2008, 05:45	#11
LUTNIT Trader rating Join Date: Dec 2005 Location: Ottawa	LiPo would not have made a difference. Mechboxes breaking has nothing to do with batteries. Life of a mechbox is usually measured in shots fired.

December 3rd, 2008, 10:38	#12
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	How did the hopup adjustment wheel break? Was it from closing the upper and lower receiver halves...or some other way? I've seen a couple of the KWA M4's and the mechbox shells have been very decent to date. While you might have gotten a lemon...I sort of doubt it (no offense). If you peruse back through the threads a couple of years ago...there's plenty of info on what causes mechbox breakages. High fps (i.e. 400+fps w/ 0.20s), high ROF, aluminum pistons, aluminum piston head, cold temperatures, "stock" shells vs "reinforced" shells, v2 vs. v3, etc... From the above items...the KWA has a lot of the downsides. The rifle shoots about 420fps stock, it has an aluminum piston head (which is not thread loctighted from the factory...and I've seen the results of one coming loose), it is geared for high speed ROFs ("LiPo ready" sales pitch, right?)...and it's winter (but that's not KWA's fault ) Do: - change out the piston head to a polycarbonate piston head. I like the systema silent head sets...they're cool. - downgrade the spring to a M100 (that'll put you in the mid-high 300's...around 360-370fps, which is nice)...or a M110 if you want to be just around 400 +/-10fps. - let your rifle "warm up" to room temperature...that means getting to games early if your rifle has been in the cold trunk for a while (getting to games early is a good thing anyways). - check the shimming in any "new" rifle....be it BNIB or "like new/only fielded once" used. KWA's are very nice...BNIB. Don't: - go for high ROF setups...unless you're willing to bust mechboxes (that's just life). Writing letters with a solid stream of BBs is fun though.... - pull your rifle out cold, slap a battery in it and rip off a burst - be surprised when toys break...and there's no practical warranty for it...(i.e. you're not buying a TV from Best Buy or Future Shop). On a positive note - almost any standard or reinforced V2 mechbox shell will work as a replacement. I'm assuming that you're looking for a "front wired" one. You could try to reuse the un-damaged parts from the KWA mechbox...but it might be less trouble and easier to buy a complete new one. You will need to reuse the KWA M4 nozzle. However, if you're replacing both the hopup and the mechbox, it might be easier to switch over to a "normal" one that doesn't have the notches and slots that the KWA one has (don't know for certain...none of the ones I've handled has had a broken nozzle/upper-hopup). Best of luck, Tys

December 3rd, 2008, 11:59	#15
m102404 Tys Trader rating Join Date: Apr 2006 Location: Toronto	Two of the KWA's that I've come across needed a ship on the sector gear, and almost every KWA (7-8 to date) that I've worked on had lateral play in the bevel gear. Was it going to lead to a catastrophic failure...can't say 100% for certain. Was it nice to know that things were setup nicely...100% for certain. For the ones that needed shimming...it may have been from how far the bearings were pressed into the mechbox shells...it may have been from variances in the gears or the bearings themselves. From my determination, they needed reshimming (and I do know from feedback from some of the owners that their rifles are still going strong). But, most certainly, they were all quite nicely setup right out of the box (i.e. worlds ahead of junkers like Dboys...or even nice setups with nice components like G&P complete boxes). You can take the most precisely machined piece of anything and put it into an assembly, where upon it's precision and the ultimate end result is immediately dependant on much more than any one components precision. Factors such as QC and tolerance stacking come into play. Certainly good enough...is good enough. But there's always better... My statement to the effect that checking the shimming of any AEG (new or used) is a good idea stands (but you are certainly free and most welcome to disagree!).

Cracked Mechbox...KWA M4A1

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