Robitronic scalpel Assembly instructions

1. Differential
The Scalpel differential works great with the grease contained in the Scalpel Box. But there are some points to be
considered, to ensure optimal function.
a. Be careful not apply too much differential grease during assembly. Too much grease impairs the operation
and smoothness of the diff. Too much grease also attracts too much dust in the differential, which leads to
excessive wear to the diff.
b. Look at the correct installation direction of the disk shims. Incorrect installation of the disk shims limits the
adjustability of the differential.
c. Tighten the differential nut carefully, if the differential nut is to firmly tightened, the differential will not operate
effectively.
d. With stronger motors (Brushless) it is recommend to tighten the differential a little bit more otherwise the rear
tires will break loose when accelerating.
2. Front wheels
Please check during assembly that the front wheels spin smoothly. Loosen the wheel nut slightly if the front wheels are
not spinning smoothly.
3. Front knuckles
Due to the production process some items may not fit together properly. The front knuckles may be a little loose, in order
to get the fit just right follow the following steps.
a. Degrease the metal parts (Wheel axle and the socket for steering axle)
b. Use red thread lock on the outside surface of the socket for the steering axle.
c. Use red thread lock in the cross hole of the wheel axle.
d. Now install the wheel axle and the socket for the steering axle with the front knuckles.
e. Carefully remove any excess thread lock fluid from all places on the knuckle.
f. Wait, until the thread lock is completely hardened.
g. Now assemble the steering arm onto your Scalpel and test to make sure the steering is moving freely.
Tips´n Tricks
In order to have the maximum fun with your Scalpel and
to bring you the optimal performance on the track, here
are some valuable tips on the assembly, tuning and
installation of the RC-components.

Degrease the metal parts (Wheel axle and the socket for steering
axle)
Use red thread lock on the outside surface of the socket for the
steering axle.
Use red thread lock in the cross hole of the wheel axle.
Now install the wheel axle and the socket for the steering axle with
the front knuckles.
Carefully remove any excess thread lock fluid from all places on the
knuckle.
Wait, until the thread lock is completely hardened.
Now assemble the steering arm onto your Scalpel and test to make
sure the steering is moving freely.

4. Steering arms
Check the operation and smoothness of the steering arms. If the stop nut is too tight, loosen the stop nut for free
movement.
5. Loose Adjusting nut of rear shock and Power Pod
While you drive, vibrations can loosen the adjusting nut of the rear shock and power pod. Apply thread lock on the internal
thread of the adjusting nut during assembly.
6. Battery holder
Unfortunately a small description for the battery holder is
missing in the instruction manual. The battery holder has
different sized holes. Please find out which hole is smaller and
larger before assembling the battery holder. The smaller hole
belongs on the inside of the chassis, so that the pin can be
pressed in firmly. The outside hole is larger, for easier
changing of the batteries.
7. Servo-Size
The optimum Servo-Size is 30x30x12mm (H/L/D). Bore distance 36mm. During testing we had excellent results with the
Hitec HS81MG-Servo. If you don’t like to cut your servo to countersink it into the chassis, you can also put some washer
under the Servo mount.
8. Radio gear installation
In order to get maximum handling from your new kit you want to pay close attention when installing your radio gear.
Avoid cable tangle, use nylon zip-ties for clean wiring. Loose cables that rub on the body, or against any moving parts on
the care will affect the handling in a negative way.

Very important! Route the motor cables so that the power pod can move freely in all directions.
Be sure to check movement of the rear pod with the body installed, use of larger connectors can restrict the rear pod
movement.
9. Battery Connections
Only use battery connectors for 2/3A cells to ensure a proper function.
Route your battery cables as shown in the picture.
The battery should always be set in the chassis with some free play to avoid any chassis tweak.

10. Optimal Installation of a Brushless system
If you would like use a brushless system in your SCALPEL, you need the special brushless motor mount (RA2069)to use
a brushless system from MAMBA or TEKIN. In the picture you can see a TEKIN RAGE brushless system installed in the
SCALPEL. This System fits better in the vehicle, if you remove the housing from the Speedo and enclose it in heat shrink.
In order to achieve cleaner wiring, the switch was removed from the Speedo and replaced by a short bridge. Likewise you
can remove the plugs between the engine and Speedo and solder them directly.
11. Vehicle settings
Here are some important fundamental tips to help set up your new Scalpel.
TWEAK
Follow the sequence of steps in order to adjust the tweak of the Scalpel correctly. This will ensure that you set up your kit
so that it is easier to handle and will drive straight forward.
a. Front axle: Adjust the wheel camber to approximately 0° with the help of the suspension rebound movement
set-screws.
b. Adjust the pressure of the spring to be equal on the left and right site.
c. Set the chassis on a surface that allows the front axles to extend down as far as possible. Use the set screws
on the arms to adjust the ride height so that both front arms travel down the same amount.
d. Check the camber of both front wheels again, readjust to 0° if necessary.
e. Next check the toe-in of the front axle. Optimal is 0°.
f. Ride Height: Set the vehicle on a level surface with the wheels on and check the ride height. The ride height
should be approximately 3-4mm. If necessary you can change the ride height by using the washers at the
knuckle. To adjust the rear ride height you can change out the transmission plates.
g. Rear axle: Loosen the nut on the friction disk absorption system, in order to allow friction free movement of
the power pod. Raise the chassis off the ground so that the wheels are touching. (During this procedure the
front wheels should be touching the ground at all times.) If the rear wheels touch at the same time, the power
pod is perfectly adjusted. If one rear wheel touches first, you have to correct it with the adjusting screws at the
t-bar, until both rear wheels touch the ground at the same time.

Vehicle Set up on the Track
After you have tweaked the Scalpel correctly, you can move on to setting up your kit on the track.
Steering adjustment
Limit the right/left balance of steering so that the vehicle drives with full steering angle equally left and right.
A good value for cornering is a turning radius of approx. 50cm.
Spring pressure on the front suspension arms
Adjust the pressure of the front springs to that the suspension rebound movement set-screw reaches the chassis
if the suspension arm is released.
Spring pressure on the middle absorber
Adjust the knurled nut from the absorber so, that the chassis does not sag when viewed from the side.
Friction disk absorption system
Apply some differential grease under both friction disks, in order to ensure free movement of the friction disk system.
On a fast track with higher grip give more pressure on the springs for the friction disks. On lower traction tracks you
can try it without grease and less pressure.
Tires
Always use tire traction sauce, if this is permitted on your racing course. Always use it on the rear tires. The front tires
should be lubricated depending on mixture and grip of the track, but only up to the half (internal half of the tire).
Apply the tire traction sauce and let sit at least 10-20 minutes. Dry the tires before you start driving on the track.
If your Scalpel is too aggressive to drive it is advisable to apply super glue (CA) to the outside of the front tires. This
reduces the front axle grip and makes the vehicle easier to drive on difficult tracks (carpet condition).
If the front tires wear in a conical pattern after a while, you should adjust the camber. The front axle is optimally adjusted,
if the front tires wear evenly across the tire.
Have Fun with
your Scalpel !