Velocity Arms JG mechbox?

[Rabbit]

Recently acquired a Velocity Arms mechbox for next to nothing.

Just wondering if anyone has cracked one of these open and if the internals are actually decent.

Im under the impression that VA guns use JG as a rebrand.

Its working perfectly and firing some what hot - just wondering if anything should be replaced before slipping it into one of my projects for a re-sale.

The only thing i could really see is the type 1 ported silver cylinder with what looks like an orange polycarb piston.

[JLiang]

If it's got nylon bushings, replace them with metal.

Also, reshimming is always a good idea.

Maybe lowering the spring a notch would be beneficial, especially if you want it game-worthy.

[89db]

In mine, I had metal bushings, metal spring guide, and the rest is pretty standard/decent, like JLiang said reshim/regrease it and it should be good to go.

[Rabbit]

Ya, now that I look I can see the metal spring guide as well and confirmed metal bushings.

89db - did yours have the orange piston too? If so we probably have the same one - hows your overall performance?

I might as well crack it open and have a go at the shims then.

[89db]

Yeah, I am at 3000bbs on it and it is going smooth so far. It seems to be tough and consistant. I have a Tightbore barrel and ARS hopup rubber on my M4, and the FPS only varies of 3 to 4 FPS every shot, which mean that the stock gearbox doesnt leak, decent nozzle etc.
I just found a picture of it.

[MaciekA]

I have the same gearset as this gearbox, but in a different gearbox.

It handles around 407fps @ 20rps @ 7.4V admirably. I am pretty certain we don't share the same cylinder (though mine is also a JG), but I have found the JG cylinder to produce the strongest "piston push seal test" result out of all the cylinder and o-ring combinations I've tried.

The bean-shaped cam on the JG sector gear suggests a possible use in high speed setups. I've noticed during some high-rps experimentation on my JG V3 mechbox that this bean-cam was the only one out of all the sector gears I tried that was able to pull the tappet plate far back enough to clear the nozzle for high speed feeding in that particular setup.

Perhaps this will spur some project ideas ..

I tend to approach a lot of players at games who are sporting guns of interest to me, and for a while I was polling players on their experiences with the VA (JG) M4s. The most common issues I've seen on the field seem to be double feeding (maybe that bean cam isn't so appropriate in the V2?) and minor cycling issues. In each case I could easily imagine anybody with a bit of time and patience making these gearboxes work well with a bit of shimming, o-ring stretching, AoE, grease, etc. That and feeding it significantly more juice .

[Rabbit]

Wow.

Hidden gem/diamond in the rough gearbox?

JG has that "low end" rep for AEG's but this is all sounding to prove other wise.

I'll be field testing mine this season.

Good looking out guys!