Parts to Upgrade a Dboys M4 CQB/R

hoplite

Thinking of using my Dboys M4 CQB/R as a 'project' AEG.

I'd like to improve range and rate of fire.

Have looked at mechbox.com and that will be my reference site for any
tinkering with the gearbox.

Completely new to this so here's a few questions;

• Version2 gearbox in the m4?
• What gearbox parts should I replace?
• Recommendations for a 9.6V crane stock battery
• Springs, Pistons?
• Should I replace barrel?
• Should I do something with the hop up unit?
• Stock motor ok for now?

Advice would be appreciated and dont worry I have another AEG so I wont be out of action when things go horribly wrong.

conor-mr2

Cant help you there! But Id be really interested if you post your findings and dealings in a review/guide of some sort. Im sure others would concur!!

hoplite

Conor-Mr2 wrote: »

Cant help you there! But Id be really interested if you post your findings and dealings in a review/guide of some sort. Im sure others would concur!!

Will be happy to oblige. Assuming I dont turn the aeg into a paperweight

liamo333

Get the FTK on rsov. Make sure you get the standard one not the 300% one because the 300% one is not suited for a 1j spring. Also systema turbo motors are great and will up the ROF to about 20 rounds a sec.

hoplite

Me's typing www.rsov.com more money heading over to HK

Fiach Dubh

If you are looking to increase range a good quality hop-up unit will serve you better then anything else. Raw power doesn't help much with range at all, I have a number of AEG's firing a joule but the hops aren't great so the effective range suffers. I hear Element hop units are good for the cheap cost, around TM performance level, better then the hop-ups in most clones anyway.

hoplite

Fiach Dubh wrote: »

If you are looking to increase range a good quality hop-up unit will serve you better then anything else. Raw power doesn't help much with range at all, I have a number of AEG's firing a joule but the hops aren't great so the effective range suffers. I hear Element hop units are good for the cheap cost, around TM performance level, better then the hop-ups in most clones anyway.

Something else for the shopping list thanks.

kdouglas

• Version2 gearbox in the m4?
  yes
• What gearbox parts should I replace?
  the stock m4 gearbox is pretty good, i threw a systema turbo motor into mine (although only for a few hundred rounds) and it ran fine, i'd leave the gears alone, upgrade the piston and piston head, maybe the cylinder and cylinder head too, re-shim the gearbox though if it's even remotely noisy, might want to consider replacing the bushings with bearings if your going for high rof, but i havent done any tests yet to see how much of a difference they make, but they reportedly do increase rof
• Recommendations for a 9.6V crane stock battery
  sanyo batteries are great, just get a decent quality one really, if it looks cheap then it probably is
• Springs, Pistons?
  any of the 1J springs will do you, as i said above about the piston
• Should I replace barrel?
  its a bit late to be digging my m4 out of it's box right now, but im pretty sure it has a tightbore barrel installed from factory, alot of clones seem to recently
• Should I do something with the hop up unit?
  the hopup unit itself seems to be pretty good aswell, i'd put in a new hopup rubber though (buy several, they are handy spares to keep)
• Stock motor ok for now?
  the stock motor is identical to the TM EG700, but as liamo said, systema turbo motors are great and are easily capable of 20rps (and higher) but they will cost you twice the price of a standard motor, there's also the systema magnum motor which combines high speed and high torque, but this isnt necessary for 1J springs, they are built for higher power

on a personal note, high rate of fire is great for a laugh, but not entirely necessary, i run my m4 completely stock except with a 9.6v battery, this gives 14rps (as opposed to 11rps with an 8.4v), which is fine for normal use

from a skirmish point of view, spending a few hours practicing to improve your aim will do alot more good then spending stupid amounts of money on a high rof setup

hoplite

kdouglas wrote: »

• Version2 gearbox in the m4?
  yes
• What gearbox parts should I replace?
  the stock m4 gearbox is pretty good, i threw a systema turbo motor into mine (although only for a few hundred rounds) and it ran fine, i'd leave the gears alone, upgrade the piston and piston head, maybe the cylinder and cylinder head too, re-shim the gearbox though if it's even remotely noisy, might want to consider replacing the bushings with bearings if your going for high rof, but i havent done any tests yet to see how much of a difference they make, but they reportedly do increase rof
• Recommendations for a 9.6V crane stock battery
  sanyo batteries are great, just get a decent quality one really, if it looks cheap then it probably is
• Springs, Pistons?
  any of the 1J springs will do you, as i said above about the piston
• Should I replace barrel?
  its a bit late to be digging my m4 out of it's box right now, but im pretty sure it has a tightbore barrel installed from factory, alot of clones seem to recently
• Should I do something with the hop up unit?
  the hopup unit itself seems to be pretty good aswell, i'd put in a new hopup rubber though (buy several, they are handy spares to keep)
• Stock motor ok for now?
  the stock motor is identical to the TM EG700, but as liamo said, systema turbo motors are great and are easily capable of 20rps (and higher) but they will cost you twice the price of a standard motor, there's also the systema magnum motor which combines high speed and high torque, but this isnt necessary for 1J springs, they are built for higher power

on a personal note, high rate of fire is great for a laugh, but not entirely necessary, i run my m4 completely stock except with a 9.6v battery, this gives 14rps (as opposed to 11rps with an 8.4v), which is fine for normal use

from a skirmish point of view, spending a few hours practicing to improve your aim will do alot more good then spending stupid amounts of money on a high rof setup

Thanks KD lots of stuff to consider there. The reason I am taking this project on is not so much to improve the gun for skirmishing but more to understand whats happening under the hood on an AEG. I'd like to be in a position to repair my own stuff and understand what effects performance.

So I think step one is to strip and reshim the gearbox and purchase a 9.6v battery.

After that I will look at piston head upgrades.

Thanks again.

kdouglas

no problem, it's not extremely difficult to open a gearbox to be honest, first time you do it you'll be a bit edgy, but take your time and you'll be fine

couple of tips;

when your opening the gearbox, lay it flat on a table, stick a screwdriver in the hole in the back behind where the spring is and push down (not extremely hard, but you'll feel a little bit of resistance), then take the top half off, this will hold the spring in place so that everything doesnt fly across the room

if your still worried about things flying across the room, but the entire gearbox inside a plastic bag and open it inside, that way any parts that fly out will be caught

it's not uncommon to hear a "pop" sound as you open the gearbox, this is caused if the piston is in anyway compressed when you open the gearbox (as it releases when you take the top half off), the gears will normally pop out of the shell too

increasing rate of fire is not too difficult below 20rps, after that things get interesting, but even just upgrading to a 9.6v battery will give a decent rof that you might be happy with

Stercus Accidit

Ha I've just started the exact same process with my m4a1!

About to get the 9.6 volt battery, will fit in the fore grip fine as far as I know.

cqbr has the ris grip right?

But battery is all I'm doing for now.

Does the high speed motor depend on voltage in the battery at all or is it quicker in general regardless of voltage? Ie does it draw more power from the batt?

I'm investing in a smart charger too.

kdouglas

the high speed motors definitely draw more current from the battery, i got about half the number of rounds out of a 1400mah 9.6 with a systema turbo than i normally would with the stock motor and same battery in my m4
it also requires a minimum 9.6 battery or a high quality 8.4, wont run at all on those cheap clone 8.4v batteries

Stercus Accidit

The reason I want to upgrade rof etc. is to get a more responsive semi-auto also.

Does the higher volt battery and the motor do this? separately also?

Is there any way to get the gearbox to act like the TM psg1 in this respect?

Ye know the way it cocks after each shot rather than during the trigger pull.

kdouglas

yea, trigger lag will be improved with a higher rof alright

i've never opened a psg1 gearbox so im not sure what way it operates exactly, but it'd be interesting to find out if it's possible to modify a standard gearbox to do this

hoplite

I suppose its also useful to understand the current performance of your aeg before you rip the guts out of it. So I am considering investing in a chrono. Kdouglas did I see you up at HRTA one day with a laylax satellite chrono?

This seems to be the only chrono that can also measure ROF.

http://www.fire-support.co.uk/store/comersus_listCategoriesAndProducts.asp?idCategory=151

The guarder chrono also looks good but no ROF unfortunately.

kdouglas

nope, that was Dr_Pepper, but im looking for a chrono myself at the moment and im going to be picking up that laylax one

the way i currently measure rof is using my laptop and a microphone, record the sound using a piece of software called audacity and count the peaks, examples here

Stercus Accidit

I got my 9.6v battery for the m4a1, the rof is class now, and semi is very responsive.

The news is this, a 9.6 fits perfectly in the front handguard of a dboys m4a1 without modification, and from what I've heard the gearbox is well up to this voltage.

Gatling

just found this on redwolf ,might help with future upgrades,
http://www.redwolfairsoft.com/redwolf/airsoft/ReviewDetail?reviewID=179