Ghost Rabbit GR1 rear differential (0 min 16 sec)

As mentioned with another video the quick-access design in our car is not limited to the front diff only. As you can see, the same system is used at the rear axle as well.

The box on the cover is the housing for the optional LED tail light.

Ghost Rabbit GR1 suspension flex (0 min 33 sec)

The 4-link solid rear axle suspension gives an impressive 185 mm of axle articulation. Combined with its high ground clearance and remote diff locks this will allow for some serious off-roading...

Ghost Rabbit GR1 suspension assembled (0 min 48 sec)

Ground clearance under the chassis is very high with nearly 120 mm, which greatly enhances off-road capabilities.

The trailing arm front mount is bolted to the bottom of the chassis tub and reaches to the outside through a hole in the side of the tub. That way the chassis' strong 5 mm sidewall works as an additional brace without the need for more bolts. This improves the strength of the mounting point significantly without causing inconvenience for maintenance tasks.

Quick-access design for the Ghost Rabbit GR1 front differential (0 min 16 sec)

Quick-access design for the Ghost Rabbit GR1 front differential.

Only the front section of the transmission housing has to be removed for maintenance like change of lubricants or checking for wear.

Using quick releases for major components is a basic design concept of the GR1. The effort for servicing our car shall not be increased due to a inconvenient design. For the same reason we try to keep the number of bolts and nuts relatively low.

Ghost Rabbit GR1 solid rear axle assy (0 min 20 sec)

The rear axle housing consists of four main components, all fully CNC machined. Only four screws are required to take the housing apart. The housing is very strong, yet keeping costs for spare parts reasonable.

A one-piece machined housing may look gorgeous on the shelf, but needing a replacement can easily break the piggy bank.
One has to keep in mind that in a machine-versus-nature scenario nothing on earth is indestructible. It is in the nature of things that the operation of any vehicle also requires spare parts at some time. Therefore we always keep an eye on the costs of ownership when designing our parts.

Front differential unit of the Ghost Rabbit GR1 with the steering system attached (0 min 16 sec)

Front differential unit of the Ghost Rabbit GR1 with the steering system attached.

The next parts arrived from a supplier, so we can make some progress with the assembly.
As with our 2WD car, the GX1, the steering system features a dedicated servo saver for every steering servo. However, for the GR1 linkage plates, centerlink and the bracket connecting the servo saver posts with the front gear box are CNC machined from billet aluminum to improve strength and match the cars design.

Trailing arm mount for the Ghost Rabbit GR1 (0 min 19 sec)

The mounting blocks for the chassis side end of the trailing arms for our Ghost Rabbit GR1 arrived. A small but nevertheless important part for the assembly of the car.

The mounting block is designed for low cost of ownership, keeping the expense for replacing components in case of a crash at a minimum.
The design also allows for a large angle of articulation for improved suspension movement.

Trailing arm mount for the Ghost Rabbit GR1 (0 min 19 sec)

The mounting blocks for the chassis side end of the trailing arms for our Ghost Rabbit GR1 arrived. A small but nevertheless important part for the assembly of the car.

The mounting block is designed for low cost of ownership, keeping the expense for replacing components in case of a crash at a minimum.
The design also allows for a large angle of articulation for improved suspension movement.

Ghost Rabbit GR1 diff lock parts (0 min 17 sec)

This is a more detailed view on the Ghost Rabbit GR1 diff lock parts. The larger part is the locking side plate for the diff housing, the smaller one is the disc which locks one output shaft of the diff to the side plate when pushed towards the side plate by a servo. Once both parts are engaged the positive-fit connection will transform the diff into a spool.
Of course, both parts are made of tool steel and will be heat treated.

Parts of the GR1 remote diff lock mechanism (0 min 16 sec)

Parts of the remote diff lock mechanism for our Ghost Rabbit GR1.
The disk will lock one output shaft of the differential to the differential case when activated by a servo. The ramp style design of the activating disc's clutch side allows for easier engagement, the spring between both components keeps the clutch reliably disengaged during normal operation.

Motor mounting plate of Ghost Rabbit GR1 (0 min 34 sec)

The first part of this video shows the CNC processing of an actuator disk for the diff lock of the Ghost Rabbit GR1. The part will be heat treated after the processing.

The second part of the video shows the motor mounting plate for the same car.
While most of its shape is processed on a CNC milling machine, the final steps of machining the bearing seats and some other surfaces which have all to be concentric are done on a CNC lathe.

A CNC milling machine is by design not capable of providing the same precision for these steps as a lathe. A lathe gives truly round and concentric results because the part itself rotates, not the tool.
A CNC milling machine makes a circle in many small steps, it interpolates the rounding. This is usually sufficient, but a lathe is clearly superior here.

Therefore we go the extra mile and use a lathe for these important steps of the processing. By doing so we achieve a precision for the bearing position of 0.005 mm."

Center gearbox of the Ghost Rabbit GR1 (0 min 17 sec)

The internal structure of the center gearbox of the Ghost Rabbit GR1 has been designed to make disassembly and maintenance as easy as possible.
The modular design allows for working on the internal components without the hassle of pulling all gears, shafts and bearings apart.

Motor quick release of Ghost Rabbit GR1 (0 min 16 sec)

Motor quick release: The first gear stage (which is normally inside the center transmission housing) is only slipped onto the motor. No screws in the pinion required.

Center gear box of Ghost Rabbit GR1 (0 min 16 sec)

The center gear box will feature a quick release for the motor pinion, no screws which may come lose are required.

Currently the front, center and rear gear boxes are not fully assembled yet, because we're still waiting for a few parts to arrive. Some parts for the differential locking mechanism have to be CNC machined, a square hole requires wire cutting for a precise result, some other parts are still in the plating process. The manufacturing takes a lot of different steps, so please be patient and bear with us.

Assembled front differential unit of our Ghost Rabbit GR1 (0 min 18 sec)

Assembled front differential unit of our Ghost Rabbit GR1.
Fully machined all metal transmission housing, the differential itself runs in large 20x32x7 mm bearings for real reliability.

Springs for the rear axle disconnect system and the stabilizer bars for GR1 (0 min 19 sec)

The springs for the rear axle disconnect system and the stabilizer bars for our Ghost Rabbit GR1 returned from the surface treatment process.
They have been nickle plated to improve corrosion resistance and appearance.

Ghost Rabbit's center transmission (0 min 16 sec)

Complete bracket with intermediate gears and bearings for the primary gearing in the Ghost Rabbit's center transmission. Since this bracket can be put together as a separate unit which will be secured and supported by the transmission case, assembly and maintenance are simplified and convenient.

3D CAD view of the rear axle (0 min 14 sec)

3D CAD image showing the full metal rear axle of the Ghost Rabbit GR1.

Aluminum servo arms (0 min 58 sec)

Carbon steel materials of Ghost Rabbit GR1 (0 min 16 sec)

Worried about parts will rust while racing in water? Worried about rusting will affect the appearance of parts? Please don't worry now, all carbon steel materials of Ghost Rabbit GR1 are electroplated (except pins, gears, internal parts, etc.)