Vfc Avalon keeping spring compressed.

[surkon]

So I got my hands on the new Avalon monster series aeg.

Here is my issue. It seems like the gearbox is pre compressing the piston. Which leads to awesome trigger response. But in my experience with springs they don't like to be squished for extended periods of time. And to attest to that point when I chronoed it out of the box it was shooting 375-380 with a 0.20g bb. And now 3 days later it's getting about 360.

Is this right?

[Proliphic]

Originally Posted by surkon

So I got my hands on the new Avalon monster series aeg.

Here is my issue. It seems like the gearbox is pre compressing the piston. Which leads to awesome trigger response. But in my experience with springs they don't like to be squished for extended periods of time. And to attest to that point when I chronoed it out of the box it was shooting 375-380 with a 0.20g bb. And now 3 days later it's getting about 360.

Is this right?

Sounds like it has Auto pre cocking to improve your trigger response and I wouldn't worry too much about the spring staying compressed because with the gearbox assembled and spring installed even with the Piston fully forward the spring is always compressed approximately 40%.
As for your FPS issue that may be an air leak in your piston head or cylinder or possibly your hop up as the chrono will be different with the hop up off versus on

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[lurkingknight]

have you set the hopup on to lift heavier bbs? Fps will drop as more hop is applied. That is normal.

Spring is already compressed when installed. Springs also don't magically lose their springiness by staying compressed, otherwise you'd see cars driving around collapsed completely on the bump stops of the dampeners. They lose springiness by cycling.

[ThunderCactus]

I've left springs fully compressed for 9mo before with 0fps drop.
Springs only lose tension from being worked. If they're shitty springs, they haven't been worked in, and they'll lose tension much faster in the first 2000 shots or so, but once they settle they'll shoot that fps for a long time.
Prometheus works in their springs, and I've got an MS100 that's 8yrs old and still does 345fps

[Fenrir92]

I wouldn't worry about about FPS loss with a compressed spring. However leaving the spring compressed causes unnecessary stress on your GB internals. I know VFCs have good build quality but I wouldn't risk reducing the longevity of the GB.

[surkon]

Ok good stuff guys. Must be that spring setteling like you say. All my chrono tests were done with minimum hop up as .20g bbs seem to curve up even at that setting. I was more concerned that the gb wasn't functioning as intended. Springs aren't big money and I have a hand full to spare. Since posting last I have swapped springs and fps has levelled out completely. But now I have another issue which may or may not be related. Only 2 separate instances switching from full auto to semi I was getting a nice little 2 round burst. Not a double feed but two shots both with speed behind them. A cycle back and forth from full auto and everything is good. Makes me wonder what the mosfet is thinking.

[lurkingknight]

it's not thinking. The avalon mosfet is just a mosfet, it does not have hardware and software that give it fire controller parts, so it can't "think".

You are experiencing overspin. The geartrain is parked wherever it stops after full auto. If it happens to be in the right spot, there is enough power in the motor to overcome the initial shot and have enough momentum to shoot a full cycle and then some. The only thing that stops aegs from going full auto is the cutoff lever which flips the trigger shuttle away from the trigger contacts. The lever is mechanically moved by the sector gear at a certain point in it's rotation. Faster gear sets and stronger springs overcome the motor momentum, so knowing how to balance your torque/rpm from the motor/battery vs the mechanical load is a bit of an art for some aeg builders.

The behavior you are describing is borderline normal. Since there's no real way to determine where the gears stop when you let go of the trigger in full auto, you could get 1 cycle, you could get 1+. If you are constantly overspinning in semi auto, then it could be an issue of wear and tear of the cutoff lever or slow death of the main spring, then that is not normal.

[surkon]

Thanks lurkingknight. That makes sense. After a good days run with the aeg it did well. No complaints all day. Possibly having a different spring helped with that over spin.

[Proliphic]

I've seen the same issue with a krytac and the way to fix it was to put it on full auto and fire for 3-5 seconds and then switch back to semi and it would no longer shoot a 2 rnd burst on semi but only a single shot. Not sure no long that "fix" works for as it wasn't my gun but I didn't hear anything more about the problem that day while playing...

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