DLC SRV - WE GBB Rifle valve sets

[DarkLite]

I'm designing some valves to use in the WE GBB rifle series. This thread will serve as a discussion thread and a testing thread.

My primary concern is creating a method of power control which is more consistent than using a restrictor disc or an NPAS.

 

The restrictor disc is cheap and generally more consistent than an NPAS but can prevent the rocket valve from closing all the way and can in extreme cases cause off-axis spin if the exit hole isn't perfectly concentric.

 

The NPAS is great for adjusting without taking the nozzle apart, but unfortunately due to it's nature tends to unadjust itself which can be a total pain in the *albartroth* and cause major consistency issues. Furthermore, installation often requires permanent modifications to the rear of the nozzle body.
 

My plan: design, manufacture and distribute a set of valves which provide you 3-5 options for power output with increased shot-to-shot consistency which don't require any more effort than taking the nozzle apart and dropping the new valve in.

The valves would be most likely 3D printed in Nylon using SLS which would give the best finish and accuracy (which is damned important for something this small) and the set would include valves which hopefully encompass a range of velocities from 0.5J (250fps with 0.2g) to 2J (465fps with a 0.2g) on a ~300mm inner barrel.

 

My first port of call will be the WE M4 range, as I own one and can test it out easily, but I will definitely be expanding the range to the WE AKs, G39s, SCARs, MSKs etc and also to the TM range of GBBs once I can get my hands on some to use as test beds. For now I won't be touching the GHK GBB series because they already produce 1J nozzle sets and also they superglue their nozzle assemblies together to stop people from fiddling with them.

If there's demand I'll also do TM GBB pistol valves (and therefore, WE/KJW/VFC/etc pistols which use copies of that system).

 

My question is this: Pricing is yet to be confirmed as I have to assess production costs, but what would you, the end customer, be willing to pay for a set of these valves?

[Beeingmyself]

Sounds like a great idea but

Just like any tool which is supposed to have as many function as possible none will ever be really good.

Instead of 3-5 options why not aim for 2 or maximum 3 and have better and more secure settings?

[DarkLite]

Sounds like a great idea but

Just like any tool which is supposed to have as many function as possible none will ever be really good.

Instead of 3-5 options why not aim for 2 or maximum 3 and have better and more secure settings?

 

The valves will have no moving parts or adjustments, for the best possible consistency. So if I had 3 in a set, you'd have 3 possible power outputs to choose from. If I had 5 in a set, you'd have 5 possible power outputs.

[Siavash]

I am very interested in this new design but prices will have to be no where more than £10 - £15 as Npas is around that price anymore you will loose out on customers.

[Brigg]

I just made a set of similar WE valves out of brass the other day for a friend.

 

 

I made 6 but one was in the bcg during the picture. I found them very consistant, if the tolerances for the outer diameter were spot on. I had consisntency of under 10 fps on some, which I felt was good.

 

Now, sorry that I cant help with a price since I just make them, but If i were to hand machine them as I was, I would want at least 10USD per valve just for the work involved.

[DarkLite]

I did look at turning them on a lathe, but the issues are:

 

1) I don't have a CNC lathe or access to one, which means I'd have to do them by hand and that will inevitably either suck up aaaaaalll my time or they wouldn't be consistently machined

2) Machining them out of aluminium/brass would get expensive quick, plus heavier nozzles wouldn't work so well with the lower powered variations of my design due to longer closing times thanks to increased inertia

3) The design I'm going to use has some complex internal geometry which would be an utter *albartroth* to machine by hand and would require both lathe time and mill time

 

That being said, very nice work on those nozzles. Lovely finish.

[Brigg]

No CNC access here either. I machined them on manual a mill and lathe. And i think with a good smooth bore, and a rounded end to it, you get more consistency then the stock WE valve with the little pointy nub in it. Or at least that was my experience, YMMV.

 

The gas is already turbulent coming out of the magazine, so its unlikely any internal geometry will help to the degree that it would be worth not doing a straight bore with a ball end cutter.

 

Not sure what you mean by the inertia bit, but admittedly Im no expert.

 

Of course, Do I think the manual option is commercially viable? Of course not.

[DarkLite]

No CNC access here either. I machined them on manual a mill and lathe. And i think with a good smooth bore, and a rounded end to it, you get more consistency then the stock WE valve with the little pointy nub in it. Or at least that was my experience, YMMV.

 

The gas is already turbulent coming out of the magazine, so its unlikely any internal geometry will help to the degree that it would be worth not doing a straight bore with a ball end cutter.

 

Not sure what you mean by the inertia bit, but admittedly Im no expert.

 

The valve essentially starts the blowback cycle by sealing the nozzle (IE: moving forwards and seating fully). The longer it takes to do that, the more gas is getting wasted after the bb has left the barrel and the longer it takes for the blowback cycle to begin. Heavier nozzle = more inertia to overcome = slower seal time.

[renegadecow]

Maybe with brass and the spacer at the back is made so thick for a low fps setting. But if it were aluminum it would still weigh next to nothing.

[DarkLite]

My main sticking point is that with SLS 3D printing, I can get a machine to *suitcase* out 1000 of them in the same time it would take me to make 10 on a lathe and mill. It'd keep the end price down to reasonable levels, whereas if I was making them on machines by hand the labour costs would be obscene.

[Beeingmyself]

The valves will have no moving parts or adjustments, for the best possible consistency. So if I had 3 in a set, you'd have 3 possible power outputs to choose from. If I had 5 in a set, you'd have 5 possible power outputs.

Arh I see then it makes very good sense. Best of luck with it

[Fox62]

Hey DL, have you tried this one? http://shop.ehobbyasia.com/action-aluminum-cylinder-bulb-for-we-m4-ak-pdw-scar-m14-g39k-gbb-series.html#.VoVFrBXhDGh . If so, how do you think the consistency of your product would match up?

 

While the market is flooded with valves (you can probably build a set of 3-5 that would serve different FPS, although probably not for very low ones like <1J), there's no offerings for sets, so I think this is a nice idea.

 

I have been using WE GBBs for about 4-5 years now and have worked on a lot of them and would definitely appreciate a product like this and would pay 20-30 USD for it. I imagine it might solve the inconsistent "FPS gap" I've seen and haven't been able to fix in some systems (specially the WE AK) with NPAS or different valves than stock (they jump from being quite consistent at, say 330 FPS to a few shots at 375, but they are consistent in these two different speeds). I think a more friendly price, like $23 would work just fine.

 

Also, thanks for storing my *suitcase* at your place so many times (; (Joey's friend here).

 

 

FoxSixTwo

[renegadecow]

The valve in your link serves no other purpose over the stock part.

As for the WE AK, use LFS discs. I have a DIY version in mine and have been able to adjust it from 350fps to 410fps by going from a 3mm hole to a 3.5mm hole. Modification to the stock floating valve and spring were necessary as the extra thickness of the disc kept the floating valve from fully closing and weakening the blowback.

[Rob15]

For 3 - 5 valves, providing the print quality is good I would be looking at selling them for around £18 - £28 for a pack, possibly at the lower end with it being 3D printing. I do something similar for the KWA MP9/MP7s with a pack of 2 CNC machined non-adjustable power reduction valves and those sell for £12 for the pack which seems to be the right sort of price point, at least for the design.

 

Are you back in the UK now? If you are I might be able help if you decided to go down the machined metal route now I have a fast little CNC production lathe which happily holds +/-0.01mm tolerances all day long, depending on the design of course.

[DarkLite]

For 3 - 5 valves, providing the print quality is good I would be looking at selling them for around £18 - £28 for a pack, possibly at the lower end with it being 3D printing. I do something similar for the KWA MP9/MP7s with a pack of 2 CNC machined non-adjustable power reduction valves and those sell for £12 for the pack which seems to be the right sort of price point, at least for the design.

 

Are you back in the UK now? If you are I might be able help if you decided to go down the machined metal route now I have a fast little CNC production lathe which happily holds +/-0.01mm tolerances all day long, depending on the design of course.

 

I am indeed back in the UK! Thanks for the offer on the CNC lathe time, but I'm going to stick with 3d printing unless it turns out to be totally unworkable in terms of material strength (which I doubt it will).

 

Hey DL, have you tried this one? http://shop.ehobbyasia.com/action-aluminum-cylinder-bulb-for-we-m4-ak-pdw-scar-m14-g39k-gbb-series.html#.VoVFrBXhDGh . If so, how do you think the consistency of your product would match up?

 

While the market is flooded with valves (you can probably build a set of 3-5 that would serve different FPS, although probably not for very low ones like <1J), there's no offerings for sets, so I think this is a nice idea.

 

I have been using WE GBBs for about 4-5 years now and have worked on a lot of them and would definitely appreciate a product like this and would pay 20-30 USD for it. I imagine it might solve the inconsistent "FPS gap" I've seen and haven't been able to fix in some systems (specially the WE AK) with NPAS or different valves than stock (they jump from being quite consistent at, say 330 FPS to a few shots at 375, but they are consistent in these two different speeds). I think a more friendly price, like $23 would work just fine.

 

Also, thanks for storing my *suitcase* at your place so many times (; (Joey's friend here).

 

 

FoxSixTwo

 

No problem mate!

 

As Renegadecow has said, that valve you've linked to doesn't really outperform the stock valve and in some cases will perform worse. My design is drastically different.

[Brigg]

I wonder if a steel valve would be any good, or if it's just break the nozzle.

 

Couldn't be that much force on it.

[renegadecow]

But if it rusts it could get stuck in the forward position.

[Rob15]

But if it rusts it could get stuck in the forward position.

Stainless steel If I were making a part like this and I wanted it to be steel I'd be looking at 303 stainless steel as the first choice anyway, but for airsoft aluminium is quite often more than sufficient anyway.

[DarkLite]

Again, there'd be issues with the increased mass and inertia of the valve (compared to nylon) causing inefficiency. I'm aiming to get +-5fps variance if I can.

[DarkLite]

UPDATE: first prototypes are in. Some issues already identified vis-a-vis thicknesses which will need tweaking. It would seem that for parts this small, SLS nylon will shrink slightly as it cools. The difference is about 0.5mm but that's enough to make for problems.

[paranoiddroid]

I'd love a set for the WA guns

[DarkLite]

I'm afraid I have absolutely no interest in making sets for the WA M4 platform.

[paranoiddroid]

Dang I want something better than my npas