Downgrading

MagicIRL

Whats the best way to do it? I've heard from general grape vine chatter that a drilled piston is basically the lazy mans way of doing it and that a cut spring is much better.

Can anyone confirm or deny this please?

Chuck the Buck

MagicIRL wrote: »

Whats the best way to do it? I've heard from general grape vine chatter that a drilled piston is basically the lazy mans way of doing it and that a cut spring is much better.

Can anyone confirm or deny this please?

Changing the spring is the correct way to downgrade, cutting is bad, drilling is just looking for trouble in the future (swarf in the cylinder, assuming you don't drill a hole in the piston or piston head).

Puding

change the spring, if you going to open the gearbox to cut the spring you might as well just replace it

DeBurca

Best way to down grade your AEG is to change the spring, cost = 1 Spring

Next best is to cut the spring so as to reduce the speed of the piston not a bad way to achieve the required < 1 joule and you are cutting a spring that you should be replacing anyway, Cost = Zero
Should you wish to later change the spring to a proper spring you can easily do so, Cost to put things right = 1 Spring

Next worst way is to drill the air nozzle, what you are doing is creating a air leak and bleeding some of the excess air so that less than the full potential energy is used to propel the BB, Cost = Zero
Should you wish to later to undue things you will need to replace the air nozzle that you drilled a hole in and also fit a proper spring like you should have done first day, Cost to put things right = 1 air nozzle & 1 Spring

Last method and the most destructive method is to drill a hole in the side wall of the cylinder again what you are doing is creating a air leak and bleeding some of the excess air so that less than the full potential energy is used to propel the BB, Cost = Zero
Should you wish to later undue things you will need to replace the cylinder and fit that spring like you should have done originally if you are lucky but most times you are not that lucky as some of the swarf from drilling the hole has gone into the cylinder and you will also generate a burr on the inside of the cylinder wall which will very quickly tear the o-ring that forms the air seal on the piston and 9 times out of 10 will also damage the piston head, Cost to put things right = 1 Cylinder, 1 Piston head & 1 Spring

One final thought about drilling the air nozzle or the cylinder while both methods work in reducing the power output of your chosen AEG the overall energy of the piston is still the same as it is propelled by a spring that has a power output greater that the required 1 joule and this energy propels the piston into the front of the gearbox and the shell has to absorb this energy
I have seen many a gearbox both cracked and broken because of the drilled hole method of downgrading favoured by one or two retailers

MagicIRL

So if Im to buy an M4 from MIA, What spring should I buy to have installed intoead of a drilled piston?

DeBurca

MagicIRL wrote: »

So if Im to buy an M4 from MIA, What spring should I buy to have installed intoead of a drilled piston?

An m90 should give you 310ish

Shiva

DeBurca wrote: »

An m90 should give you 310ish

Depends on the gearbox type......I can't remember whether its version 2 or 3, but one of them can quite often give results in the region of 340 fps with an MS90.

DeBurca

I have seen an M95 push an AK to 340ish

Inari

Replacing the spring is NOT the fix-all solution. There is also the issue of gear ratios and timing to factor in. This is not a problem with all AEGs, mind you.

The gearboxes in your AEGs are designed. Most of which are designed for the American high fps market i.e. where the money is. When you replace the spring, there is nowhere near as much power as before, and the gears can over spin due to less load, causing a whole pile of issues. Drilling the cylinder in this case solves the issue, as the motor and gears are still pulling the load they were designed to. By drilling the cylinder, you are passing the problem further up the chain; you are creating an air leak. Where's the problem in this? Inconsistent shots. Absolutely no argument from me on this one.

What is the BEST way to downgrade a gun for PERSONAL use? Design the gearbox yourself; replace virtually everything. Put in gears of a suitable ratio, a spring of MS85 or so, and a correct cylinder (ported/non-ported depending on inner barrel length). It is the most costly solution, but you avoid repairing as problems occur.

Just to clarify - drilling is destructive, it can cause problems. You'll have no argument from me on that one. However the most common 'problem', is that the consistency of your shots is not as high as with a non-drilled cylinder. Replacing the spring without thought to the rest of the gearbox has its own issues, with over spinning gears etc. Cutting the spring also has problems since the spring was made to be a specific length for a reason.

Firekitten

Inari wrote: »

Replacing the spring is NOT the fix-all solution. There is also the issue of gear ratios and timing to factor in. This is not a problem with all AEGs, mind you.

The gearboxes in your AEGs are designed. Most of which are designed for the American high fps market i.e. where the money is. When you replace the spring, there is nowhere near as much power as before, and the gears can over spin due to less load, causing a whole pile of issues. Drilling the cylinder in this case solves the issue, as the motor and gears are still pulling the load they were designed to. By drilling the cylinder, you are passing the problem further up the chain; you are creating an air leak. Where's the problem in this? Inconsistent shots. Absolutely no argument from me on this one.

What is the BEST way to downgrade a gun for PERSONAL use? Design the gearbox yourself; replace virtually everything. Put in gears of a suitable ratio, a spring of MS85 or so, and a correct cylinder (ported/non-ported depending on inner barrel length). It is the most costly solution, but you avoid repairing as problems occur.

Just to clarify - drilling is destructive, it can cause problems. You'll have no argument from me on that one. However the most common 'problem', is that the consistency of your shots is not as high as with a non-drilled cylinder. Replacing the spring without thought to the rest of the gearbox has its own issues, with over spinning gears etc. Cutting the spring also has problems since the spring was made to be a specific length for a reason.

I dont quite think what you just said is true... its correct in a sense, but not the way you meant. Timing does exist in all aegs, sure, the myth is that it varies significantly outside of specific 'high speed gears'. In pretty much all othersm its identical, and suprisingly, is designed for roughly 280fps, with roughly 70-800 rounds per minute. Why? because nobody bothered to change that design that they all copied from Tokyo marui's original design, for the japanese market.
If you actually downgrade a cloner gun, you'll have something quite hardwearing, due to the fact that the gears are toughened, to deal with US higher fps 'market'. That's the only difference with the FPS level... Strength. 400 in a stock tm gun will much its gears in short order, the different materials cope better. Ratio is identical, because the piston is still moving x distance, at y point in the rotation, and in theory we're using the same battery and motor, just raising the fps.
It physically can't 'overspin' as the guns design stops that happening. Anti reversal latch, and piston stop end up catching the gears... If it does overspin, it could only spin round and catch a second time...

Unless they are specifically high Speed or high Torque gears, which most are NOT in stock guns, then the ratio will be absolutely FINE for 320. The only difference for a high fps us market, is the toughness of the material, not ratio.


Your point about length is great however. yes, its meant to be a certain length, cutting it makes it all twangy and nasty, and wears faster. (and if you do cut, dont be a retard like some of my ex customers, and cut the tightly coiled end by mistake, and end up taking 200fps off. *sigh*

TNTQ

Different gearboxes give different results with the same spring.

A Guarder 85 Spring gives 310 in a VFC gearbox but only 280/290 in the likes of a Dboys gearbox.

The reason for this is the quality of the gearbox with regards to 'sealing', hop-up chamber movement and general quality of the parts.

And yes, drilling is the lazy, uncaring way to do it. I saw one in the workshop the other day that had 5 holes drilled in it. Kinda looked like a thin whistle

Firekitten

hes right, air seal is the biggest fps one...
Its funny, people downgrade a gun, get it bang on 325 or something, then wack a tightbore and new hop etc in thier gun, and wonder why its hot again....

MagicIRL

Im looking into buying a KWA M4 SIR (Probally from MIA) and am I right to now pressume that a new spring will give me my desired 320fps or whatever, without overspinning my gears or jamming it up due to ratios and such?

Firekitten

MagicIRL wrote: »

Im looking into buying a KWA M4 SIR (Probally from MIA) and am I right to now pressume that a new spring will give me my desired 320fps or whatever, without overspinning my gears or jamming it up due to ratios and such?

Sorry to say this Magic, but ignore that, completely. A new spring will be ABSOLUTELY fine... downgrading will not cause ANY of those problem, they are not relevant whatsoever to this exersise. However, i wouldnt recomend the kwa tbh.

se conman

Maybe I am missing something here but if you are buying an AEG from an Irish retailer why would you need to downgrade it ?

MagicIRL

What I ment was, what was the best way to do it and/or have it done. If I want to do it myself at a later date (i.e. if I added in a tighbtore and it went hot) I figured it would be a valuable piece of information to know. I would hope to know my AEgs internals inside and out in the near future so I can attempt to upgrade it or any future AEGs myself.

Thanks for all the info. Why would you not recommend the AEG Fire? Bad experience with one yourself?

Leftyflip

MagicIRL wrote: »

What I ment was, what was the best way to do it and/or have it done. If I want to do it myself at a later date (i.e. if I added in a tighbtore and it went hot) I figured it would be a valuable piece of information to know. I would hope to know my AEgs internals inside and out in the near future so I can attempt to upgrade it or any future AEGs myself.

Thanks for all the info. Why would you not recommend the AEG Fire? Bad experience with one yourself?

KWA are a "C U Next Tuesday" to get parts for, pistons are slightly bigger or smaller than standard, the air nozzle is different and the hop chamber isn't the same as the TM one.

If I'm downgrading an AEG and it's a few fps over, I'll cut off a few coils, it does nothing bad as long as you file the cut point, I've done it many, many times and have never had an issue.

MagicIRL

Leftyflip wrote: »

KWA are a "C U Next Tuesday" to get parts for, pistons are slightly bigger or smaller than standard, the air nozzle is different and the hop chamber isn't the same as the TM one.

If I'm downgrading an AEG and it's a few fps over, I'll cut off a few coils, it does nothing bad as long as you file the cut point, I've done it many, many times and have never had an issue.

Could you recommend a good website to order parts for a KWA from so?

Firekitten

Mostly they are one of the more unreliable m4 aegs out there for the price. G&P, G&G, and others are equally priced if not cheaper, and far better reliability. if you want the high speed angle, go for the g&p... lovely, and gorgeous externals too.

All the KWA m4s ive worked on as a shop tech and freelance, have been terrible to sort.

elDiablo79

if you buy a gun in M.I.A it will be most likely downgraded already. and the way theyve always downgraded their guns is by drilling the cylinder which is the worse way and will cause lots of problems down the line.

TNTQ

AirsoftEire.com

Got a shipment of KWA defenders in the other day, blasted things shooting at 390fps. Customer needed one in a rush, told him i'd have the spring swapped in 20 minutes.

Stuck an Ultimate M100 spring in (normally produces 325ish with CA/G&G models), result? 385fps. Time, 7pm. argh

Rang him up, he needed it asap and agreed to clipping the spring, so spent another 15-20 minutes re-opening the whole thing. Using my best guess, I picked a spot and clipped the end off and tapered and flattened the exposed end. Stuck it back in, was shooting at 320fps.

It's an absolute pain working out what springs produce what power in what guns, M90 springs for example produce no more than 270fps in VFC M4s. But its the best way of doing it.

Steve