Build Tips
& Tricks
This is a comprehensive build guide intended to help Radiosistemi owners build their new RR8 kits. We will
be outlining several tips and suggestions that we have found to be beneficial while assembling these kits.
Some of those tips will aide with such things as build speed and ease, while some will focus on kit
maintainence and durability. While we will cover a large portion of the build, it is intended only to provide tips
to ease your build. This guide is NOT intended to replace the instruction manual, only supplement.
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M3x10
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M3x8
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12
13
0133036
TCCE25X10
M2,5x10
X2
X3
M3x3
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THROTTLE & BRAKE LINKAGE SET 0133023
X1
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M3x12
M3x4
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M3x10
X4
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0133006
5X8X2.5
RR8 Build Tips & Tricks
Pre-Build Assembly
Pivot Balls - It is recommended to assemble the pivot balls the night before you plan to build your kit. This will
allow time for the thread locking compound to setup and harden. The parts are located in Bag 03.
Before assembling the pivot balls, note that
one side of the ball has a flat area. This will
be the side we screw the stud into.
Apply a liberal amount of red thread lock to the
studs. You can also use green compound for a
more permanent solution, however this will
make disassembly challenging.
Spin the ball onto the stud, snugging the ball
down tightly.
RR8 Build Tips & Tricks
Pre-Build Assembly
Pivot Balls - It is recommended to assemble the pivot balls the night before you plan to build your kit. This will
allow time for the thread locking compound to setup and harden. The parts are located in Bag 03.
Install the M3 screw into the end of the stud.
This screw is used as a safety mechanism to
prevent the balls from working loose. Apply
red thread lock to this screw as well.
Although unnecessary, you may choose to
sand the edges of the screw down.
Allow the thread lock to setup for 24 hours. If
you cannot or do not wish to wait, you may
continue on using caution to avoid
unscrewing the ball from the stud.
(Continued)
RR8 Build Tips & Tricks
Shocks
Note: Several steps of the assembly have been omitted.
Insert the O-Rings into the spring
adjustment nuts. Slide one side of the
O-Ring in, and then push the other side in
with your finger nail.
To thread the shock shafts into the shock
ends, without risk of marring the shaft with
pliers, you can simply install the nut on the
upper piston thread. Use a 5mm hex wrench to
spin the nut and shaft into the lower shock
end. The nut will come off quite easily once the
shaft is fully threaded into the shock end.
There are two sides on the plastic shock
ends. One is rough and one has a flat
circular area. You want to insert the ball
through the side with the flat area.
RR8 Build Tips & Tricks
Shocks
Note: Several steps of the assembly have been omitted.
Use a pair of flat needle nose to install the
balls into the ends. This will prevent marring
of the plastic.
Shafts fully assembled.
Assemble the lower shock seals. Note the
order of the O-Rings and Bushings. I
greased both O-Rings and the middle
bushing. I did not grease the outer bushing
to prevent dirt accumulation.
RR8 Build Tips & Tricks
Shocks
Note: Several steps of the assembly have been omitted.
If you happen to slide a loose O-Ring over a
shock shaft, you'll notice the O-Ring is
oversized. Not to worry.
The seal is designed this way. When the
O-Rings are inserted into the shock body, they
squeeze down to the proper size. This creates
an ideal seal that will last much longer and
provide better performance vs. using an ORing that is sized to the shaft.
The shock pistons are tapered delrin and are
drilled to 6x1.3mm. Install the taper down to
give a little better pack over the large jumps.
If your track is rough, you may consider
installing the taper up to give a softer
compression.
RR8 Build Tips & Tricks
Differentials
Note: Several steps of the assembly have been omitted.
Quickly check and set backlash by
assembling the diff case and the bevel gear.
Make sure to use the blue diff gasket so the
gear and case will be the correct assembled
width. Do not install any internals yet.
Add shims and the 8x14 bearings to the diff.
You also need to install the 8x16 bearings and
the pinion gear into the bulkhead.
With the pinion and diff installed into the
bulkhead, press on the bearings with your
fingers (holding the gears tight) and check
backlash. You want the gears to rotate
smoothly, with no notchiness and minimal
play. I used one .2mm shim on the gear side,
no shim on the case side. If you need to add
or change the shimming, you can do so now
without having to disassemble the entire
diff. DO THIS FOR BOTH F & R DIFFS.
RR8 Build Tips & Tricks
Differentials
Note: Several steps of the assembly have been omitted.
Apply a thin bead of grease around the
outdrives, especially around the secondary
seal. You also need to apply grease to the ORings.
Grease all O-Rings.
Applying grease to the washer behind the
large internal gears will help prevent oil
seepage. Only grease one side, install shims
so the grease faces O-Rings.
RR8 Build Tips & Tricks
Differentials
Note: Several steps of the assembly have been omitted.
After the outdrives, seals and cross pins are
installed into the differential case, you will
need to install the set screw into the case to
seal it off. Put a small dab of CA glue onto
the set screw to provide a secondary seal
against oil seep.
Install the set screw into the case. The set
screw should be flush with the outside of the
case.
Lower diffs assembled.
RR8 Build Tips & Tricks
Differentials
Note: Several steps of the assembly have been omitted.
Install the diff gaskets into the bevel gears.
The fit is tight enough to hold them in place
until the gears are installed on the case.
Several steps of the build were omitted in this
tips guide. You will need to complete assembly
of the differentials. 5000cst Front and 3000cst
Rear oil is recommended.
(Continued)
RR8 Build Tips & Tricks
Driveline
Note: Several steps of the assembly have been omitted.
The RR8 uses an aluminum slip cover to
retain the CV pins in place. In order to keep
the cover itself in place, you need to align
the holes and insert the set screw.
Install the driveshafts onto the pinion. Use
your thumb to press on the pinion while
squeezing the CV joint with your index and
middle fingers. There is no shimming required
on the pinion gear.
Assemble the bulkhead(s) and apply grease
to the bevel and pinion gears.
RR8 Build Tips & Tricks
Front End
Note: Several steps of the assembly have been omitted.
Assemble the outboard driveshafts. Grease
the pins & barrels before assembling them.
You can use the 15x21 bearing to hold the pin
in place if necessary before you insert it into
the steering knuckle.
Assemble the knuckles. No real tricks or tips
needed here. It's quite straight forward.
Shouldered Pivot Ball = Bottom, Hexed Pivot
ball = Top
RR8 Build Tips & Tricks
Front End
Note: Several steps of the assembly have been omitted.
When assembling the sway-bar links, do not
bottom out the set screw. You only need to
thread it in 1/2 way.
For now, leave the droop screws flush. It is
recommended to adjust these once the car is
complete.
Assemble the arms onto the knuckles.
Remember, the shouldered pivot ball goes
on bottom, and the hexed pivotball goes up
top.
RR8 Build Tips & Tricks
Front End
Note: Several steps of the assembly have been omitted.
Assemble the bulkhead. It's recommended
to either grease the M3x30 screws, and/or
use a power screwdriver.
The suspension inserts are notched for quick
reference. No notches = 0mm, One notch =
0.5mm, Two notches = 1.0mm
When pressing the inserts in, the tolerances
are tight to prevent excess slop. You may
need to use a set of pliers to get them
seated fully.
RR8 Build Tips & Tricks
Front End
Note: Several steps of the assembly have been omitted.
The RR8 is designed with multiple
adjustments in mind. You can slide the arm
forward and back up to 6mm. Start with a
single thin shim upfront. Add appropriate
amount of shims to the inside of the arm.
Drill out a 2.5mm hole into the largest sway
bar holders. After, insert a M3x4 set screw.
You can now use the set screw to adjust slack
with different sized sway bars, instead of
swapping the entire holders.
Front mostly done.
RR8 Build Tips & Tricks
Steering
Note: Several steps of the assembly have been omitted.
The 3mm chassis is pocketed to accept the
steering posts and make assembly easier.
Make sure to line them up correctly.
Install the lower bearings onto the post, this
will prevent you from loosing them during the
build. Additionally, install the upper bearings
after assembly.
After much testing, it is recommended to
thread the servo saver nut down 4mm. This
will provide a strong tension, but provide
just enough flex to prevent damage.
RR8 Build Tips & Tricks
Upper Plate
Note: Several steps of the assembly have been omitted.
Apply red loctite to the UF mount.
To aid in assembly, insert a body clip to get a
good hold of the body mount while screwing it
down.
Installing the upper steering plate and UF
mount before installing the front end on the
chassis will be much easier.
RR8 Build Tips & Tricks
Braces
Note: Several steps of the assembly have been omitted.
The front and rear braces can be locked or
unlocked into "Flex" mode, depending on
track conditions. Tighten the screw to lock
the brace solid, or loosen to allow the brace
to flex.
If you plan to run the brace(s) in flex mode,
apply some grease to inner portion of the
upper brace. Note: the picture shows the rear
brace.
Install the e-clips on the retaining pins.
Brace is now fully assembled.
RR8 Build Tips & Tricks
Chassis & Center Diff
Note: Several steps of the assembly have been omitted.
When installing the brace onto the car, leave
the upper mount screw loose. This will allow
you to align the lower screws much easier.
Once the bottom two screws are torqued
down, you may then torque the upper screw.
Assemble the center differential using the
same tips as the F & R differentials shown
above. Install a 0.1mm shim behind the
bearing on the case side.
(Continued)
RR8 Build Tips & Tricks
Brakes
Note: Several steps of the assembly have been omitted.
Using 250 grit paper, sand down one side of
the backing pads. You only need a light
scuff. After sanding, clean them with
degreaser.
Mark the pads. You want your cut pads to be
just inside of the holes. This way, you won't
have to clearance the pad around the holes.
Cut the pads on your marks. A sharp utility
or hobby knife will work well for this. You
can also score it and snap it.
RR8 Build Tips & Tricks
Brakes
Note: Several steps of the assembly have been omitted.
Apply an even layer of CA glue to the
backing pad.
Line up the brake material across the TOP of
the backing pad. It will hang down on the
bottom, this is fine, we'll cut it off next.
After the glue sets up for a minute, use a
sharp hobby knife to trace along the bottom
of the steel back pad, cutting out the
overhanging brake material.
RR8 Build Tips & Tricks
Brakes
Note: Several steps of the assembly have been omitted.
Set the air-gap to approximately 0.75-1.0mm.
You can do this by gently tightening the
screws all the way down (with the pads and
rotors installed) and then loosening them
1.5 turns.
Adding a 1mm spacer to the brake pad screws
on the spur gear side is recommended. It will
prevent the gear from rubbing the screws
when under heavy stress. You can also use a
slightly shorter screw.
When assembling the brake linkage, a
minimal distance between the brake arm and
the brake cam is required. Approximate a
5-8mm is ideal. You also may need to angle
the brake lever down slightly to properly
align the lever with your servo horn.
RR8 Build Tips & Tricks
Rear End
Note: Several steps of the assembly have been omitted.
Assemble the rear bulkhead.
Install RF toe block.
Install the assembly onto the chassis. Note:
Do not install the 2 rear M4 screws. Wait
until you have the RR block mounted on
before screwing these in. Doing this will
make sure your rear bulkhead stays square.
RR8 Build Tips & Tricks
Rear End
Note: Several steps of the assembly have been omitted.
Adding a ROND4X10X03 shim to each inner
hinge pin will help removing any slack that
may occur as a result of varying anti-squat
and toe angles.
Install the rear arms & RR block. Again, grease
the screws and/or use a power screwdriver.
Once the RR block is installed, install the
two remaining M4 screws on the underside
of the chassis.
RR8 Build Tips & Tricks
Rear End
Note: Several steps of the assembly have been omitted.
Assemble and install the rear brace. Here it
is fully assembled. Remember to grease the
upper brace if you plan to ever run it
unlocked. I run the rear unlocked 90% of the
time.
A quick easy way to install the balls into the
rear links is to place the ball on the table, large
side down, slip the rod end over the ball and
press down with the palm of your hand.
Once you assemble and install the hubs,
driveshafts and camber links, you need to
attach the links to the tower. For easier,
quicker adjustments, install the M3x20
screw backwards as shown. This will make it
easier to adjust the links, as you will only
need to remove the nut, instead of the entire
screw.
RR8 Build Tips & Tricks
Final Assembly
Note: Several steps of the assembly have been omitted.
The tray posts can be a bit hard to hold with
just your hand, and using pliers will damage
them. Use the upper and lower screws, and
two 2.0mm drivers to install the upper
screws. Once installed, remove the lower
screw and install the tray onto the chassis.
Run the wires through the cutouts.
If you want to run both the power and
charge leads out of the box, you need to trim
away a small section of the ridge on the
inside of the lid. Doing so will prevent the lid
from compressing on the wires.
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