Lh aug v3 gear box

AEG Automatic Electric Gel Blaster
81

Can always check your nozzle length/seating into the t-piece by testing preload on the nozzle prior to reassembly.

I would always do a dummy check by looking at the nozzle through the t-piece feed tube and and hand fit the barrel/t-piece to the lower receiver with the gearbox installed.

When the barrel assembly is bought into contact with the nozzle, I would always make sure that the nozzle was pushed back towards the gearbox by 2-3mm, which guarantees that the nozzle is fully seated in the t-piece and is under preloaded tension from the tappet plate return spring :ok_hand:

If the nozzle didn’t move, that was a sure sign that the nozzle wasn’t reaching the t-piece at full extension.

This was fixed by removing the nozzle rubber and simply adding one or two small o-rings behind the nozzle rubber to space it further forward until I found the right amount of preload onto the nozzle when assembled :+1:

Be careful not to go too far forward with the nozzle spacing though, because this can also lead to causing issues with feeding if there’s not enough room left for the gels to squeeze past the nozzle when fully retracted.

If this became an issue, then the opposite could be done by glueing a correctly sized o-ring into the t-piece to tighten up the nozzle spacing without causing any feeding issues…… but this could only be done on certain model blasters that have a good gap between the feed tube and the nozzle seat surface inside the t-piece.

Also check the nozzle/cylinder head tube for air sealing at full extension, not by the normal method of holding it back against the cylinder head with your finger over the nozzle.

I found many even “double o-ringed” aftermarket performance Alloy nozzles to have good sealing when fully retracted, and yet absolutely zero sealing when extended :roll_eyes: I even sometimes ran standard nylon nozzles on aftermarket Alloy cylinder heads because they provided the best combination of all of the different spare parts I tested together for a very good seal over the useless aftermarket part sets!

Easiest method to test the nozzle/piston head tube seal at full extension is to fit your tappet plate into the nozzle, find its extension point, then use one hand to grip around the tappet/cylinder together with your thumb over the end of the nozzle on that same hand, then use the other hand to cycle the piston in and out of the cylinder to test for pressure/air leaks.

It’s a bit tricky, but once you’ve mastered the technique, it’s the only way to properly check nozzle sealing at full extension. :ok_hand:

So…… there’s two critical things to check out, as well as properly sizing your gels to your barrel I.D.

Many people make the mistake of rushing out to get the “hardest” speciality gels to run through their stock 7.5mm barrels, but the problem is that most hardened gels will only grow to 7.0-7.2mm……. and also don’t “squish” when fired to seal against the inside surface of the barrel to make a perfect air seal.

Small hardened gels in this situation leak air like a sieve inside of the barrel letting all of your precious FPS to run straight past them :joy:

82

Thanks for that information exactly , I was looking for. Cheers

83

No worries, always happy to help and hope you find out where your FPS is disappearing to :+1:

1 Like
84

Solid advice for this issue, Doc… :+1: and not to hijack the post, but the following would be relevant to the OP’s A3 issue.

My M14 EBR is having the same problem (got it from BigMuthaDrums who somehow managed 320FPS out of it.)

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Tried a nylon Gen 8 nozzle, a brass double o ring aftermarket, an alloy Vector nozzle (slightly longer), nozzles with o rings added,.o ring in the t piece… you name it. I’ve chanted over it, burned jos sticks, tried divining rods, a rabbit’s foot, thrown salt over my shoulder for three days… :laughing:

Most reviews of these EBRs sees them hitting around 100-150FPS stock… Low Guido upgraded one and only managed low 200s. I’ve currently got mine sitting around 230, that’s with the brass nozzle, an M100 spring and WI heavy milkies. Smaller gels return sub 200FPS.

Point is, as Doc so eloquently put it, it’s a trial and error process until you hit the right setup, and it’s made twice as difficult if the OEM settled for an average setup as in the case of the EBR, or somebody who’s loosely classed as a blaster tech’s had his gorilla mitts on it previously, which seems to be the case with the AUG.

@Bigmuthadrums I don’t know what voodoo you used to get 300+ on this EBR, but I tip my hat to you, good sir :joy:

85

Hahaha, cheers, certainly got a good laugh from that!
One other thing I forgot to mention was how some of the cheap OOTB Blue/Green gels used to make more FPS in some builds than the better quality aftermarket gels.

I put it down to them being a bit softer and able to deform more inside the barrel for a much better air seal :thinking:

Unfortunately I never got the opportunity to fully finish experimenting with the ZB26, which was also only 170-200 FPS stock, yet got it up to 230/240 by simply stripping apart, fitting a couple of o-rings and fixing air sealing on all the standard parts.

They had a funky offset nozzle cylinder head that I was researching a replacement for at the time, but then everything had to go :frowning:

I love that EBR……. which also has quite a long barrel, which can benefit from a tighter bore 7.2mm to lower the volume of the barrel if you haven’t tried that yet?

86

I was thinking about dropping in a 7.3 IB… my go to. :+1:

87

Me too,I’ll give a smaller ID barrel a go .

88

Never say die @Clyde

There it is… took some creative problem solving, but finally sorted the air seal on my EBR… which means you can do it with your AUG :wink:

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Took a very thin o ring in the t piece to do it… as per the above advice from @DocBob.

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There’s always a solution :+1:

2 Likes
89

Congratulations :tada:
That pic is a perfect example of what I was saying about the dependence of the design of the t-piece to be able to use an internal o-ring nozzle seal.

Early model designs had the feed tube quite a distance back from the barrel/nozzle seal, which allowed plenty of room to fit an o-ring forward of the feed tube, whereas many newer models and different designs have the feed tube intersecting so close to the barrel/nozzle that they are actually drilled into the lower end of the nozzle seat :flushed:

How can those designs ever possibly provide an air seal when there’s 1/4 of the nozzle seat surface cut away?

There would be more FPS going down the feed tube than going into the barrel :roll_eyes:

I will endeavour to go back through some old phone pics and parts boxes to see if I can find an example of these useless t-pieces that I’m taking about.

Luckily enough that the EBR t-piece looks like it had just enough room to fit an o-ring in there :ok_hand:

90

And people still wondered how I was getting 400+ FPS out of a nylon Gen8 back in 2018/2019 :joy:

91

Yeah, lots of potential.in a Gen 8 gearbox, for sure. :wink:

One thing about the o ring mod on this EBR is that while it has solved the air seal issue, it’s reduced the ID of the t piece a bit… will spit heavy milkies, WI reds, ice balls and all of the softer gels out at around 320FPS, but jams up with Ultra Elites, AKAs and pretty much all of the harder gels. They’re just not soft enough to push through the o ring.

I’m okay with that… not a problem. :+1:

@Clyde might pay you to try this before you spring for a 7.3 IB… if the problem’s at your t piece, reducing your barrel ID won’t fix it. Like Doc said, if all your air’s disappearing down the feed tube, you probably won’t have enough juice to push a gel down a tighter bore. :person_shrugging:

1 Like
93

The reduced bore was to overcome barrel volume on long barrelled blasters such as the ZB26 etc that even a 100% cylinder had very little hope of producing enough air to push a gel out of the barrel at any decent speed :frowning:

Gen8 sized Cylinder heads/nozzles can move much more volume of air very quickly compared with the later smaller V2 etc size nozzles……. but the whole Achilles Heel for AEG Gelblasters/Airsoft is the cylinder volume.

Edit for an interesting side note…… stupid high rate springs could be “tuned” to be “cushioned” against slamming into the cylinder head and provide a longer “timed” air feed to the barrel when done properly.

Sometimes this actually required fitting a smaller cylinder head/nozzle to achieve this “air brake” effect on the piston, and it was obvious when this cushioning effect wasn’t being created, as it would sound like something was hammering hard inside the gearbox :flushed:

The only way to make the very best output from a limited air source is to use every single available knowledge of physics available to extract every single trick in the book to get the most out of the limits of their designs. :ok_hand:

Once all other tricks had been achieved with the gearbox/t-piece and air sealing etc, then experimenting with barrel lengths and diameters could be tested to do the last final steps of extracting the best combinations possible to achieve the highest efficiency.

Again, sometimes cheaper soft gels outperformed quality aftermarket gels, so even when the whole blaster was finished and tuned to the most performance possible, even better results were achieved by simply ignoring the mainstream narrative and testing out every single type of gel available as to what fed seamlessly and preformed the best :sunglasses:

1 Like
94

@Clyde
Wow, those LH AUG t-pieces look like an air seal’s worst nightmare!

So these are a classic example of how the feed tube actually sits forward of the tapered nozzle seal section and cuts through the seal surface, (highly visible in the section circled below) causing the FPS to blow out of the feed tube and not the barrel :flushed:

Adding an o-ring might be impossible, but definitely worth a try…… even if it means that it will only perform on softer type gels such as @Friendly_Fire mentioned…… that’s a small price to pay for such a huge improvement in FPS :+1:

It got even worse seeing that they are a split 2 piece t-piece, which you have to make sure that you glue/epoxy the two halves together and carefully inspect the nozzle seal surface for eccentricity and smoothness.

If it all janked up, you can CAREFULLY take an appropriate sized drill bit to gently use your fingers to turn and apply slight pressure to true up the nozzle seal surface.

If there’s enough meat inside the t-piece, removing 1mm of depth to true up the surface will also give that same room to be able to add a 0.5-1.0mm o-ring into the t-piece exactly as @Friendly_Fire has done :white_check_mark:

Have fun experimenting and good luck :crossed_fingers:

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95

Handy tip for the installation of that o ring too…

I used a bit of rod that was a snug fit in the back end of the t piece, then built up a ring of electrical tape a couple of millimetres thick and about 10mm from the end of the rod. Slip the o ring on until it hits the tape ring, apply CA glue to the ring then push it onto the back end of the t piece, pushing firmly to seat. Count to ten, withdraw the rod.

Acts as a alignment tool and keeps the o ring flat and central in the t piece… very important for a good air seal. :+1:

96

Thanks for the explanation, definitely a very good method for getting the o-ring centred perfectly with the t-piece and barrel :ok_hand:

I had an old piece of aluminium rod that I had tapered off in the lathe that proved handy for many different similar purposes to achieve the same result :sunglasses:

Hopefully @Clyde will be able to get some good results from all of this information!

97

Thanks DOC , i will , :wink:

98

Hi, I’ve been searching the net , for a t piece , for atomic armoury aug a1 , or army armament a1 aug t piece , have searched, and phoned, any one out their can point me to the right place., would help me sort this fps conundrum.

99

If you’re having that many problems sourcing another t piece I think your best option would be to tweak the one you’ve got.

Nothing to lose here… :person_shrugging:

100

I will carefully,I know army armoury aug a1 is the same as atomic armoury t piece , bugger , I can purchase that LH T piece easy, my LH aug has come to life and working well 280 fps. , mosfet working well, must have been 35 degrees heat.

101

Again the mosfet , was working well then again no single shot x3 shot ok , auto ok, seems the trigger is binding, on return it will run on a bit , is it still getting hot? , I’ll give it time to cool, yep this is the second mosfet replacement.