This title is
model specific. It covers all V.2 mechbox based G3
variants, including the latest G3 SAS from TM and the R8
from WELLFIRE.
Concepts presented also
apply to the entire line of CA SAR Offizier AEGs.
More than 50
countries during the past 40 years issued the G3 to its arm
forces. Even though it is no longer being offered from the H&K
catalog nowadays, a wide variety of firearms currently in
production are still based on the G3 design.
In
the world of AEG, we have G3 replicas primarily from TM. All
these G3 variants are V2 mechbox based and are having highly
similar architectures. As the owner of these
G3s, we have to face the truth that they
are not perfectly designed. In fact, they share the same
structural problems. To make them more usable and durable,
proper reinforcement works must be conducted.
For your G3
to survive an upgrade, you must first fix the problems that
come with it.
Based on the
contents of our highly successful Practical AEG Upgrade
title, this e-book goes one step further by covering G3
specific performance and maintenance issues. Concepts
presented also apply to the entire line of CA SAR Offizier AEGs
(you can think of the SAR Offizier line as the full metal
implementation of the G3 series with upgraded internals).
G3 Upgrade &
Maintenance is organized based on the primary objectives of
structure reinforcement, high FPS upgrade, high ROF upgrade and
high accuracy upgrade. In addition, a section on
troubleshooting is included.
We tell you what to
do and what to avoid so you can achieve the best possible
performance without spending all your savings. Rather than going
the cumbersome step-by-step way, we teach you the essentials
through an easy-to-read Q&A format backed up with annotated
photographs and diagrams whenever necessary.
With over 120 pages of text and illustrations, this e-book is a
MUST READ if you want to master the art of G3 AEG upgrade and optimization!
Tools you’re going to need
Proper handling of the screws
The proper ways of taking things apart and putting them back
together
MECHBOX DISASSEMBLY STEPS
COMMON STRUCTURAL
PROBLEMS, FIXES AND WORKAROUNDS
Structural problem 1: a weak front barrel mounting structure
Structural problem 2: flexy receiver and cocking tube
Structural problem 3: inner barrel wobble
Structural problem 4: the fake external barrel
Structural problem 5: the G3 SAS inner barrel
Structural problem 6: the grip and the motor plate
Structural problem 7: magazine wobble
Structural problem 8: the G3 SAS foregrip wobble
Structural problem 9: butt stock wobble
Special WELLFIRE R8 technote
PERFORMANCE UPGRADE
HIGH FPS UPGRADE
TM AEG: a baseline for performance measurement
What is proper usage?
What are the key elements of a high FPS setup?
Version 2 mechbox versus Version 3 mechbox: any difference in
stock performance?
FPS increase in meter readings VS performance increase in a
practical sense: the law of diminishing marginal gain in
performance.
0.20g BBs versus 0.25g BBs versus 0.30g BBs: the heavier the
better?
Does FPS always go hand in hand with Joule?
What is the difference between the FPS system and the Joule
system?
How do you use FPS to measure Joule?
How do you use FPS to give an estimate of the range?
Higher FPS = lower ROF?
Softer spring = Higher ROF?
Harder spring = Lower ROF?
Is 8.4V insufficient for an upgraded mechbox?
Does battery size matter?
Is battery power important for semi-auto firing?
EG-700, EG-1000 and ICS Turbo 2000
Why (and why not) should I buy the high torque gear set?
Why (and why not) should I use helical gears?
Why (and why not) should I keep the stock plastic bushings?
Why (and why not) should I replace the stock plastic bushings with
metal bushings?
What is an easy way to (more accurately) shim?
How do I tell if shimming has been done correctly?
What is the recommended order of gear insertion?
Longer spring versus shorter spring: the longer the better?
What are the major parameters of a spring?
Is a harder spring more harmful for the internals?
Installing a long spring: tricks and potential danger.
Installing a short spring: tricks and potential danger.
Why (and why not) should the spring be ground?
How to facilitate spring spinning?
What is a variable pitch spring? Is it always better for AEG?
Use of spacers for spring compression: tricks and potential
danger.
What is wrong with a custom made spring?
Systema Springs versus PDI Springs
Can stainless steel spring offer better FPS?
Can Telfon Coated spring offer better FPS?
The long variable-pitch spring is very difficult to install. What
should I do?
What can I do to reduce stress on the gears?
Can an EG1000 increase FPS (through higher torgue) over an EG700?
Why (and why not) should I use a Bore-Up Cylinder?
Why should I replace the stock cylinder on my G3 SAS?
Different guns use different cylinders that have different number
and position of openings. Why’s that?
Is it useful to block the cylinder opening altogether?
Why is it useful to put holes on the piston head? Any alternative?
Why (and why not) should I use a metallic piston head?
How about a silent head set?
Is aluminum piston more durable?
Is version 2 mechbox too fragile for M130 or above?
Do I need a heatsink motor plate on upgrade that involves M140 or
above?
How do I effectively reduce heat on the motor?
Why (and why not) is the one o’clock gear timing an issue?
Can I still use the smaller batteries to power my upgraded mechbox?
I want to hide my battery inside the grip and the stock but the
battery cells are too big. What should I do?
Chaining up your batteries: Parallel VS Serial configurations.
Should I use Sanyo battery cells for maximum performance?
How safe is it to remove the fuse? Any alternative?
Why (and why not) is it necessary to replace the stock wires?
Why is it necessary to shorten the wires? Can I use stereo wires
instead?
Why (and why not) is it necessary to replace the stock Tamiya
connector?
Are NiCd batteries superior to NiMH batteries for driving upgraded
AEG?
How do I optimize the overall performance of the stock motor?
Is it possible to increase the torque of the stock motor? If so,
how?
What else should I buy for a high FPS configuration?
What is wrong with the soda can test?
What is right with the soda can test?
What is the most accurate way to measure FPS?
HIGH ROF UPGRADE
What are the key elements of a high ROF setup?
Can I increase the ROF while keeping the FPS at the stock level by
using 9.6V battery?
Voltage VS mah – which one matters the most?
Can I increase the ROF by replacing the mechanical contact switch
with a solid state switching mechanism based on MOSFET?
Can I increase the ROF by using capacitors at the power source?
Is high ROF a major cause of tappet plate breakage?
ROF-wise, why (and why not) should I replace the stock plastic
bushings with ball bearings?
ROF-wise, why (and why not) should I replace the stock plastic
bushings with metal bushings?
How about oil channel bushings?
Why (and why not) should I buy the high speed gear set?
Should I upgrade to a Teflon Cylinder?
How about a high speed cylinder set?
What makes a ball bearing spring guide meaningless for a stock TM
gun? How to work around?
Is there any cheaper alternative to ball bearing spring guide?
Why a ball bearing spring guide alone may not increase the ROF?
Should I upgrade to an EG1000 for higher ROF?
How do I optimize the stock motor’s RPM without spending major $?
How can I increase the ROF while keeping the FPS at
near-the-stock-level?
What is the right type of spring and battery to use for this
purpose?
Is ROF over 30/sec possible?
What is the major ROF bottleneck?
Is aluminum piston better off for a high ROF configuration?
Are lighter gears better off for a high ROF configuration?
What else should I buy for a high ROF configuration?
Can I increase ROF by cutting off some teeth from the piston and
the gears?
HIGH ACCURACY UPGRADE
What are the key elements of a high accuracy setup?
How to improve accuracy with short barrel?
Can a long barrel deliver higher accuracy and range?
Why (and why not) should I replace the stock cylinder when using a
longer inner barrel?
What is good about a high precision barrel?
How to maximize the effectiveness of a high precision barrel?
What is the drawback of using a high precision barrel?
TROUBLESHOOTING
My stock G3 is dead after approximately 3000 shots. Why?
What will happen with improper shimming?
And what should I do to remedy the problem?
How do I prolong the life of the mechbox?
When the mechbox is running, the nozzle does not move at all. What
is wrong?
My mechbox got stalled after replacing the tappet plate. What’s
wrong?
My gun stopped working in semi-auto mode. What’s wrong?
What cause the piston gear to break prematurely?
My EG1000 was overheated. What should I do?
What should I do for proper motor maintenance?
What cause the strange noise from the motor and/or the motor gear?
The two screws that attach the mechbox to the lower receiver are
completely stripped. What should I do?
What causes gear stripping?
What can cause the hopup rubber to break?
How to prolong the life of my battery?
Is slow charging always good for my battery?
How to safely charge a battery?
Is NiMH battery free from the memory effect problem?
Should I fully discharge the battery every time after use?
How do I fix the battery memory effect problem?
My gun keeps mis-firing. How do I tell if this is a magazine
problem or a mechbox problem?
I suspect that the hi-cap magazine is not working. What should I
do to fix it?
What causes air leakage?
What causes double feeding?
My gun makes an unwinding noise after full auto firing. What’s
wrong?
What needs to be regularly replaced to keep my gun in good shape?
Are accessories for the G3s and the MP5s interchangeable?
Technical Appendix Guide also
included FREE OF CHARGE.Updated on July 11, 2006.
Contents:
Safety precaution
Cutting wires
Tools you don’t absolutely need
Handling of screws
Better trigger squeeze for
accuracy improvement
Ball bearings: how they work and why they break
Soldering techniques
More on battery configurations
Parallel configuration
Battery chargers
Steps needed for successful motor break in
Motor bushing break in
How does heat hurt the motor?
Adding torque to the motor Barrel length / FPS correlation and performance compensation The mechbox runs noisily on a new setup The switch plate has been burnt...
Cleaning of electrical contacts
Choosing wire: Stranded wire VS solid wire
AEG water resistance Troubleshooting mechbox electronics Troubleshooting a weak Hi-Cap mag Making your AEG quieter Do-It-Yourself Electric Motor Driven Hi-Cap Mag Achieving ultra high ROF Achieving ultra high ROF through piston teeth removal The sector gear delay loading chip Misfeed when using heavier BBs Why is One Way Piston Head preferable?
Screen shots
Special notice:
We have made the decision NOT to cover the CA 33E
in this title because: 1, CA quality control level is so inconsistent that
buying their products seems to be no different from buying
lottery; 2, the folks at CA are just reluctant to give response to
our enquiries concerning problems with their products. At this
moment we do not feel comfortable recommending their products to
our readers.