Bell B30D ADT tracked

Model "Bell B30D ADT tracked" is build with LEGO® in scale 1:17,5 and motorized using LEGO® Power Functions®. This model represents a prototype which is developed by Bell Equipment in conjunction with the Dutch company Fuhler BV.

This ADT features: PF XL motor powered driving with limited slip differentials, a length differential, M motor powered articulated steering with double acting actuators, M motor powered dumping, M motor powered air pump to operate the tracks, detailed cabin interior and 3 light units.

This Bell B30D articulated dump truck with tracks is only a prototype. Research on the Internet, not much shared on this prototype, learned this ADT is developed by the well known South African company Bell Equipment and the Dutch company Fuhler BV. It turned out to be similar to Bell B30D ADT with wheels, but modified to fit these tracks.

Besides this model is impressive and functional at the same time and great to have as a stand alone model it also works great as load. Together with the to be released "Truck T3 MkII" and lowboy "Trailer Tr8 MkII" this Bell makes this combo extremely impressive. Wouldn't you have one of these sitting on your desk or in your room or office? Keep track of progress on these models, for all instructions will be available as well for you to build it yourself!!!

A single PF XL motor is used to power the drive train. It is sitting under the hood where the actual engine would have been. It is geared down before it powers the length differential. Which is the same time the Achilles heel of this tuff machine. The inner gears of it tend to break under stress. In a future release of this model that will be solved!

The limited slip for the differentials is a simple system and yet quite effective. Both outgoing axles of the differential are connected using rubber belts with a single axle. So if one track starts to free spin the rubber belts forces the system to transfer power to the track with traction.

Large turn tables are used to mount the tracks to the chassis. This allows the tracks to tilt so they responsive to surface. A pneumatic cylinder is used to dampen the track, which prevents it from tilting unwanted when running into an obstacle. Further more with these cylinders the angle of the tracks can be manipulated. This allows the operator to overcome obstacles more easy.

Both front tracks act as a couple as do both rear tracks. This allows to tilt front tracks differently from the rear tracks. Pneumatic switches are installed to A) operate both pairs of tracks and B) open and close the pneumatic system. With the system opened the tracks are able to respond to and follow the surface. The pump is operated remotely, the switches are operated manually.

The tipping angle of 70° is approached as close to reality as possible. Real life dumpers have long cylinders which are not available in LEGO®. Even though this model has a dipper angle of a nice 62°!
For this the rotations of the motor that powers the dipper's actuators is geared down quite a lot. With this the torque is increased. Together with two hard spring shock absorber the system is very effective. When the dipper is lowered the gravity will help it to compress the shock absorbers. The shock absorbers will help the actuators to lift the dump, so gravity became an ally.

The articulated steering system has a steering angle of 45° for both directions. This is equal to the steering angle of real live articulated dump trucks. It uses two double-acting linear actuators which both are geared down to have enough torque.

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