Just Thought I'd Share My First Ever Plunge Into a Gearbox

[38super]

Took the whole evening to get into the gearbox of my Double Eagle. Added a couple of extra shims although I don't think it was too bad anyway. Just a tiny bit of play in each now. Put an o-ring nozzle in as there was a bit of a leak with the nozzle forward. Greased and lubed, put back together and it at least makes all the right noises. Yay.???

Testing tomorrow hopefully.

AoE may want a little correction although I don't think it looks too bad.View attachment 69911

One thing I've never seen on any of the videos I've watched is the maximum piston travel which surprised me. Does it really need to travel that far or is this the reason for short stroking? The o-ring almost comes out of the cylinder?

View attachment 69912

An interesting way to spend a quiet Friday night and if I'm lucky it'll as least still work. I'm not holding my breath for an improvement just yet.

 

[Adolf Hamster]

AoE may want a little correction although I don't think it looks too bad.

that looks pretty damn good, it's more about having a nice smooth pickup and a good first tooth engagement compared to the "ermegerd must be 12:00 position addz moar sorbo" that gets touted far too frequently. generally the way i do it is with just the sector gear in the box (no col/tappet plate/spring) close the shell, push the piston all the way forward and hand-turn the sector to "feel" the pickup.

much easier to do on v3 boxes admittedly.

One thing I've never seen on any of the videos I've watched is the maximum piston travel which surprised me. Does it really need to travel that far or is this the reason for short stroking? The o-ring almost comes out of the cylinder?

that is slightly further than i'm used to seeing, but if it ain't going far enough to catch then that's just how it is. if you were going to adjust the aoe then a thin (sub 1mm, maybe even 0.5mm) washer between the piston and the piston head would be the way i'd look at doing it.

that's not the reason for short stroking though, that's a rate of fire thing.

when firing the piston has to travel all that distance, which in a higher rate of fire build is the cause of pme when the sector can make a full rotation faster than the piston drops.

a stronger spring will make the piston move faster, preventing pme although this will also have the effect of increasing the fps- which is limited.

so if you short-stroke, the piston has less distance to travel, but the sector still has to do a full rotation. however the spring also doesn't get as much load, so your fps drops.

however this means you can drop in a stronger spring, compensating for the fps drop and speeding up the piston.

one downside is loss of volume, indicated in this case by the position of the port in the cylinder. you can short stroke up to this point and not suffer accuracy issues from lack of volume. of course this will depend on the barrel length of the gun, hence why speed builds tend to have shorter barrels.

the other downside of course is that your gun is now loaded like a higher fps gun with a stronger spring, but you aren't getting a higher energy for all that wear and tear (although you are getting a snappier rate of fire)

 

[38super]

Thanks for the very clear explanation. Much appreciated.

I would more likely be looking for better trigger response and accuracy which I believe would mean a high torque motor and high speed gears if I understand things correctly.

Can anyone tell me what cylinder type this is and what a suitable barrel length might be?

The original barrel is 200mm but I've dropped in a ZCI 250mm so it'll be interesting to compare them.

View attachment 69921

 

[Adolf Hamster]

not too up on the cylinder types, but given it's the stock cylinder it'll be setup for the stock 200mm barrel.

@Sitting Duck knows the cylinder types better than i do.

accuracy/range is a 3 factor problem:

-the velocity of the bb- you want this to be decently close to the site limit (5-10fps doesn't matter so much but an 0.8j gun on a 1.3j site is gonna struggle), and as consistent as possible so every bb is going the same speed- this is down to part ammo quality and a big part air seal

-the quality of the ammo- you want heavier ammo for range, and good quality for consistency, how heavy is up to you (if you're rich enough to yeet .48's then go for it) although for outdoor use in an assault gun the .3g range is a pretty decent balance between cost/performance. if you're playing indoors this doesn't quite matter so much.

-the quality of the hop/barrel setup. you're off to a good start with the zci, very good performance for the money, the hop you'll need both for air seal (linking back to the first point) and enough traction to lift heavier ammo (linking to the second point), my usual reccommendation is up to the .32 range the pdi w-hop is a nice straight drop-in, or the more premium option which will lift whatever you like is the maple leaf macaron with omega nub combo. often you don't need a new hop unit and a bit of twiddling can get everything flying straight.

trigger response seperately can be acheived in a number of ways.

i see that's got an optical mosfet, i'm guessing this is the titan clone negative airsoft mentioned in his latest video. don't know what it's specs are but if it has an option for precocking then you're laughing because that's the first and single biggest step for a snappier semi-auto trigger.

things like high speed gears/motor swaps will boost the auto rate of fire, but won't be nearly as potent for semi response if the gun has a precock set up unless you're jerry miculek and can spam the trigger faster than the gun can cycle.

 

[Sitting Duck]

not too up on the cylinder types, but given it's the stock cylinder it'll be setup for the stock 200mm barrel.

@Sitting Duck knows the cylinder types better than i do.

accuracy/range is a 3 factor problem:

-the velocity of the bb- you want this to be decently close to the site limit (5-10fps doesn't matter so much but an 0.8j gun on a 1.3j site is gonna struggle), and as consistent as possible so every bb is going the same speed- this is down to part ammo quality and a big part air seal

-the quality of the ammo- you want heavier ammo for range, and good quality for consistency, how heavy is up to you (if you're rich enough to yeet .48's then go for it) although for outdoor use in an assault gun the .3g range is a pretty decent balance between cost/performance. if you're playing indoors this doesn't quite matter so much.

-the quality of the hop/barrel setup. you're off to a good start with the zci, very good performance for the money, the hop you'll need both for air seal (linking back to the first point) and enough traction to lift heavier ammo (linking to the second point), my usual reccommendation is up to the .32 range the pdi w-hop is a nice straight drop-in, or the more premium option which will lift whatever you like is the maple leaf macaron with omega nub combo. often you don't need a new hop unit and a bit of twiddling can get everything flying straight.

trigger response seperately can be acheived in a number of ways.

i see that's got an optical mosfet, i'm guessing this is the titan clone negative airsoft mentioned in his latest video. don't know what it's specs are but if it has an option for precocking then you're laughing because that's the first and single biggest step for a snappier semi-auto trigger.

things like high speed gears/motor swaps will boost the auto rate of fire, but won't be nearly as potent for semi response if the gun has a precock set up unless you're jerry miculek and can spam the trigger faster than the gun can cycle.

don't tag me into this - I'm trying to reduce my carbon footprint/bandwidth for lengthy replies

nah it's all about right I reckon volume wise, could SS 2 teeth off the 3 steel tooth

but why complicated stuff if it all works on OK, just run it on a titchy 11.1v and should be alright

Good sharing btw...

 

[Adolf Hamster]

don't tag me into this - I'm trying to reduce my carbon footprint/bandwidth for lengthy replies

it's ok man, this place uses 100% recycled pixels

 

[Sitting Duck]

it's ok man, this place uses 100% recycled pixels

phew that's a relief coz 99% of my posts are me waffling on & on more than I need to

using 101% of the same crap I've posted previously

port is about say 43mm from front

take off say 15mm = 28mm left

multply by x10 = 280

cylinder is about right for a 280mm barrel roughly

dunno if he has the 210 stubby DE or a slightly longer one of say 310

but yeah port is roughly about right for a precision built bit of airsoft engineering

(sarcasm) or fuck it, chuck that it there and give to 5 year olds in the sweat shop to assemble for 50 cents per hour







don't know if 15mm or 12mm or 20mm is correct - don't care too much these days

but only ever a ROUGH GUIDE to begin with, but peeps usually got the gist of what I was hinting at

(same as gear ratio checking, unless you really like counting teeth/maths n shit

actually the gear ratio or 3 x bevel rotations works out very well tbh to arrive at real ratio)

as said same ol' same ol' stuff most of the time

 

[Adolf Hamster]

good to know, i know voluming tends not to be as sensitive for aeg's but can never remember the forumula.

any time i'm changing a cylinder it's always a rummage through the box o' bits followed by "that looks about right"

 

[Sitting Duck]

good to know, i know voluming tends not to be as sensitive for aeg's but can never remember the forumula.

any time i'm changing a cylinder it's always a rummage through the box o' bits followed by "that looks about right"

that's basically what all my maths n shit was all about

a rough ball parky thingy to kinda say - yeah fuck it

it's somewhere around that

It's when cylinders use the type A, B, C, D bollox

or 4/5 or 3/4 or 2/3 crap...

coz I've looked at some and thought - yeah ???, looks more like 3/4 than 4/5

or that type B looks like another claim of type D - too vague at times

measure it, lop a bit off, x10 - yeah fuck it near enough in that range

 

[Adolf Hamster]

that's basically what all my maths n shit was all about

a rough ball parky thingy to kinda say - yeah fuck it

it's somewhere around that

It's when cylinders use the type A, B, C, D bollox

or 4/5 or 3/4 or 2/3 crap...

coz I've looked at some and thought - yeah ???, looks more like 3/4 than 4/5

or that type B looks like another claim of type D - too vague at times

measure it, lop a bit off, x10 - yeah fuck it near enough in that range

does sound about right.

most of my volume adjusting shenanigans have been on hpa where it's stupid easy to adjust, although that's balanced by them being much more sensitive to such things.

 

[38super]

not too up on the cylinder types, but given it's the stock cylinder it'll be setup for the stock 200mm barrel.

@Sitting Duck knows the cylinder types better than i do.

accuracy/range is a 3 factor problem:

-the velocity of the bb- you want this to be decently close to the site limit (5-10fps doesn't matter so much but an 0.8j gun on a 1.3j site is gonna struggle), and as consistent as possible so every bb is going the same speed- this is down to part ammo quality and a big part air seal

-the quality of the ammo- you want heavier ammo for range, and good quality for consistency, how heavy is up to you (if you're rich enough to yeet .48's then go for it) although for outdoor use in an assault gun the .3g range is a pretty decent balance between cost/performance. if you're playing indoors this doesn't quite matter so much.

-the quality of the hop/barrel setup. you're off to a good start with the zci, very good performance for the money, the hop you'll need both for air seal (linking back to the first point) and enough traction to lift heavier ammo (linking to the second point), my usual reccommendation is up to the .32 range the pdi w-hop is a nice straight drop-in, or the more premium option which will lift whatever you like is the maple leaf macaron with omega nub combo. often you don't need a new hop unit and a bit of twiddling can get everything flying straight.

trigger response seperately can be acheived in a number of ways.

i see that's got an optical mosfet, i'm guessing this is the titan clone negative airsoft mentioned in his latest video. don't know what it's specs are but if it has an option for precocking then you're laughing because that's the first and single biggest step for a snappier semi-auto trigger.

things like high speed gears/motor swaps will boost the auto rate of fire, but won't be nearly as potent for semi response if the gun has a precock set up unless you're jerry miculek and can spam the trigger faster than the gun can cycle.

 Thanks for the info. I'm running decent quality (Bad Wolf?) 0.30's chronoing at 300+/-5fps (not as consistent as it should be). I have put in ZCI plastic hop unit and 250mm barrel, and Maple Leaf MR/Omega combo and an SHS double o-ring nozzle. Accuracy is about 4 hits out of 5 on a 4 inch target at 15m but I've no idea how that compares to what  I should expect. I can't do longer ranges at the moment to play around with the hop so I've set it a what seems to give the best accuracy at 15m.

The mosfet only supports burst fire, binary trigger and trigger sensitivity, no pre-cocking unfortunately. I don't know if it's possible to upgrade the mosfet.

phew that's a relief coz 99% of my posts are me waffling on & on more than I need to

using 101% of the same crap I've posted previously

port is about say 43mm from front

take off say 15mm = 28mm left

multply by x10 = 280

cylinder is about right for a 280mm barrel roughly

dunno if he has the 210 stubby DE or a slightly longer one of say 310

but yeah port is roughly about right for a precision built bit of airsoft engineering

(sarcasm) or fuck it, chuck that it there and give to 5 year olds in the sweat shop to assemble for 50 cents per hour







don't know if 15mm or 12mm or 20mm is correct - don't care too much these days

but only ever a ROUGH GUIDE to begin with, but peeps usually got the gist of what I was hinting at

(same as gear ratio checking, unless you really like counting teeth/maths n shit

actually the gear ratio or 3 x bevel rotations works out very well tbh to arrive at real ratio)

as said same ol' same ol' stuff most of the time

Thanks for the Maths tips, that post should be a sticky somewhere. I teach Maths and it's always a surprise to students that you either can't or don't need to be absolutely precise. The 250mm barrel I've got should be about right with 0.3's or at least not far enough off to be a major problem.

What this probably needs is some empirical testing to test the guidelines and give some idea of confidence intervals.

 

[Sitting Duck]

 Thanks for the info. I'm running decent quality (Bad Wolf?) 0.30's chronoing at 300+/-5fps (not as consistent as it should be). I have put in ZCI plastic hop unit and 250mm barrel, and Maple Leaf MR/Omega combo and an SHS double o-ring nozzle. Accuracy is about 4 hits out of 5 on a 4 inch target at 15m but I've no idea how that compares to what  I should expect. I can't do longer ranges at the moment to play around with the hop so I've set it a what seems to give the best accuracy at 15m.

The mosfet only supports burst fire, binary trigger and trigger sensitivity, no pre-cocking unfortunately. I don't know if it's possible to upgrade the mosfet.

Thanks for the Maths tips, that post should be a sticky somewhere. I teach Maths and it's always a surprise to students that you either can't or don't need to be absolutely precise. The 250mm barrel I've got should be about right with 0.3's or at least not far enough off to be a major problem.

What this probably needs is some empirical testing to test the guidelines and give some idea of confidence intervals.

The gun is fine as it is, it is a very cost effective gun that has a few basic bells n whistles

(prog burst, binary etc... plus the electronics take over with a quick flick/release it fires say 5 rnd burst)

yes it doesn't have pre-cocking but c'mon, for the money you get good bang for buck

considering a better optical mosfet unit is £60 upwards in a say £100~120 gun

mosfet is bespoke so if it fucks up then replace with Perun optical but use it as is

if you can find a really titchy 11.1v then run it on that for a bit of zest

but the room in the 904G stock is bloody small, they could have made it a tiny bit thicker

to accept a bigger/wider range of 11.1's

 

[38super]

The gun is fine as it is, it is a very cost effective gun that has a few basic bells n whistles

(prog burst, binary etc... plus the electronics take over with a quick flick/release it fires say 5 rnd burst)

yes it doesn't have pre-cocking but c'mon, for the money you get good bang for buck

considering a better optical mosfet unit is £60 upwards in a say £100~120 gun

mosfet is bespoke so if it fucks up then replace with Perun optical but use it as is

if you can find a really titchy 11.1v then run it on that for a bit of zest

but the room in the 904G stock is bloody small, they could have made it a tiny bit thicker

to accept a bigger/wider range of 11.1's

For what it cost me I'm very pleased with it especially how sturdy it feels. It's set for 3 round burst which suits me fine and an 1100mah 11.1v Nuprol that fits nicely.

It's cheap enough for me to be happy to mess about with and learn how it works. I thought it had all gone horribly wrong today when I pulled the trigger and nothing came out. It took a few moments to realise I hadn't wound the mag.? There's nothing like a new learning curve to keep me entertained.?

I've booked my first game for the 4th of April. Must try not to break the gun before then.

Thanks for everyone's help. This is a great forum.