KJW M4

[Andrew12]

Cheers mate, it was totally by chance I noticed it happening. I was unable to replicate the problem with the extension removed.

 

take a picture of the extension installed and seated how you had it. You might have had the same problem I did..

[Andrew12]

If you have the newest revision, the bolt is thicker and different in the middle. Not sure if Cradle has adapted all the new carrier extensions for this yet. I know we ran into this problem when I got mine from T_Hum, so he had to machine me one about 4mm shorter.

[t_hum]

Yours was a little longer than most by about 6mm in the first place Andrew. I used to make them longer and yours was one of those. Weekeny's is shorter.

[Andrew12]

Yours was a little longer than most by about 6mm in the first place Andrew. I used to make them longer and yours was one of those. Weekeny's is shorter.

 

Ok just checking. Still does not sound like a CE problem. I played this saturday with the CE and had 0 failures to lock after last round.

[senators2904]

after testing it without the valve today results were the same. i expected gas efficiency to be crappy but the full auto still stopped on me. i dunno what the issue could be. its so annoying to think that after about 5-6 months of use with propane i have to switch to 134a. i dont know why but something tells me it could be something with my trigger assembly... its just a feeling though.

[t_hum]

Have you inspected your piston seal?

[senators2904]

i'll certainly have to check it out. when i removed the piston cup before i didnt notice any outstanding cracks or tears in the seal just some discoloration.

[Andrew12]

T_Hum and I were thinking of some ways to narrow down hop issues. We swapped 3 receivers , 3 outer barrels, three inner barrels etc, still could not isolate enough. Thus you have the worlds first TDC(top dead center) hopup adjustment for the KJW M4. Will be doing some testing tomorrow. What I can say so far is that theres unlimited travel of the hop arm, its very precise and offers 'infinite adjustment' and that the hop arm does not swing side to side when pressure is applied.

 

This mod was done to mainly address two issues:

 

1. infinite hop adjustment in very small adjustments

 

2. eliminate the entire wheel design as being an issue with hop.

 

 

 

[weekenny]

Quite a good idea there nice and simple. Although I don't fancy attacking my upper with the pillar drill. Did you tap the hole or let the grub screw cut its own thread?

 

Are there still plans for a revised hop arm?

 

I'll get carrier extension pictures when I get home from work.

[t_hum]

The hole was drilled on the cnc mill then tapped. Getting the hole exactly in the centerline of the receiver is critical. We then tapped the hole.

[DesertFox]

If you were able to offer this as an upgrade, then we would have to send our upper recievers in?

[Shadow_Ocelot]

Or could you start producing receivers so then the rest of us can stop crying over wanting second full uppers?

[Kai_Wolf]

haha indeed. Im tired of crying. It looks promising though you guys. I want to see how it turns out.

[weekenny]

hmm wonder what other upper improvements could be made at the same time, maybe a VLTOR style upper

 

 

anyways

 

 

 

That's how it looks fitted. Tried again today same issue, it's intermittent but can't get it without the extension. Problem seems magnified if the gun is held with the barrel pointing down wards say 30 - 45 degrees.

[t_hum]

Yeah, if this works and I offered it as a custom service people would have to send them in for modification. Im not sure what Im going to do yet. Ill wait for testing results first.

 

Weekeny, Im baffled. Sending you a PM regarding the issue so we can figure out a way to solve it.

[suicidalsnowman]

Had a rather strange occurrence yesterday, the screw holding in my cradle airsoft piston managed to undo itself, despite being loctited in place. Originally I'd borrowed some loctite from my lab tech, who had access to every type known to man, however, I don't have that right now, so which type should I get?

[t_hum]

Blue. Red if youre never going to remove it.

[suicidalsnowman]

Cheers, I also just noticed that the velocity reducer had cut into its o-ring on its internal edges, is that to be expected?

[t_hum]

Ive seen it happen a few times. Occasionally the insides of the grooves don't duburr well enough and leave a sharp edge. Taking the o-rings on and off a lot makes it worse. New parts are going to be made on a new machine in the near future that mill-deburrs each slot. If you see a sharp edge a quick buff with sandpaper can knock the burr down.

[Andrew12]

Or could you start producing receivers so then the rest of us can stop crying over wanting second full uppers?

 

You need to go back in the thread and read what he said about creating receivers. It's just not going to happen, you want a receiver? They are about $90 imported STRIPPED. To make ONE custom, you are probably looking at 300-400$

 

I'm going to try and do some testing this afternoon if I have time, if not , tomorrow.

[Shadow_Ocelot]

Wowza wowza, hostility monster in the thread! .

I need to go back in the thread? Bud, I've had my KJW for nearly a full year now because I been reading this thread back at page 40. Learn to take a joke, I was already talking to T_Hum about it and he knew I was joking too. Sheesh, some people.

Edited September 29, 2010 by Shadow_Ocelot

[Andrew12]

Wowza wowza, hostility monster in the thread! .

I need to go back in the thread? Bud, I've had my KJW for nearly a full year now because I been reading this thread back at page 40. Learn to take a joke, I was already talking to T_Hum about it and he knew I was joking too. Sheesh, some people.

 

Your post did not come over in a sarcastic manner, mine was not hostile.

[DesertFox]

Andrew12, several pages back you said you might be able to get in a shipment of metal uppers. Any news regarding that? I'd love to make myself a cqb upper.

[Andrew12]

Andrew12, several pages back you said you might be able to get in a shipment of metal uppers. Any news regarding that? I'd love to make myself a cqb upper.

 

Yes, however they will be substantially higher priced than I had originally thought. I am trying to source another person to help import them right now, the company I was dealing with wanted $120 shipped for each one.

[Andrew12]

TDC Update:

 

TDC is a success at properly actuating the hop arm, however it is very sensitive. 1/8-1/10th turns are needed with the current threading to adjust hop. With my completely stock gun with 250mm stock barrel, my limit on engaging targets is Probably 200ft, after that the hop is too erratic. right now all I have are echo1 .28's and madbull .36's, the MB's are hitting man sized trash cans at 230ft but its only 5/10 times.