Remote Controlled - LEGO® Power Functions
Dragline Crawler Crane
In The Netherlands, dragline crawler cranes are rarely seen; I can only recall one seeing in operation when I was a child.
Draglines have a clever mechanism to load or empty the bucket in combination with a dual rope system and chains connected to the bucket. This models works exactly as the original. Trane hides 5 medium motors, 2 large motors, 2 XL motors, 4 IR-receivers and 2 battery boxes! Together these motors make sure the crane can crawl, swing, raise/lower the boom, wind/unwind the 2 drum winches with ropes, and operate a 'free fall' system whereof the drum winches are temporary released from their motors. Although this model is able to simulate this mechanism... it takes severe practise with the remote controls to do so.
The main boom consists of multiple sections. A boom foot connected to the superstructure, an extension section and a boom head. The main boom length is approximately 110 studs, according to scale, the boom length represents 22 meter.
The rope of the 'drag line' drum winch can easily rerouted to the boom head section; as such double rope lifting is possible.
Draglines have a clever mechanism to load or empty the bucket in combination with a dual rope system and chains connected to the bucket. This models works exactly as the original. Trane hides 5 medium motors, 2 large motors, 2 XL motors, 4 IR-receivers and 2 battery boxes! Together these motors make sure the crane can crawl, swing, raise/lower the boom, wind/unwind the 2 drum winches with ropes, and operate a 'free fall' system whereof the drum winches are temporary released from their motors. Although this model is able to simulate this mechanism... it takes severe practise with the remote controls to do so.
The main boom consists of multiple sections. A boom foot connected to the superstructure, an extension section and a boom head. The main boom length is approximately 110 studs, according to scale, the boom length represents 22 meter.
The rope of the 'drag line' drum winch can easily rerouted to the boom head section; as such double rope lifting is possible.
Functions
Remote Controlled
LEGO Power Functions
Crawl
Swing
Boom up/down
2 Drum winches
Freefall system
Crawl
Swing
Boom up/down
2 Drum winches
Freefall system
Technical
Clutch gears
for
Freefall system
for
Freefall system
Manual
Boom sections
Transport mode
Transport mode
Specifications
Dimensions
Boom length - 92 cm
Width undercarriage - 21 cm
Height superstructure - 18 cm
Height with Boom - 98 cm
Boom angle: 10 - 80 degrees
Lift capabilit: 250 - 500 gram
Weight - ~2,7 kg
Transport length - 65 cm
= A-frame + boom foot
Parts
2.208
Building Info
Photo - Video shoot: Reconstruction high-way A1, near Weesp, The Netherlands
Development process
Superstructure
Most of the time was spend to build a sturdy superstructure and to find locations for the many Power Functions devices.
Multiple 5x7 and 7x11 'open center frames' are used to deal with the forces applied by the boom and the weight of the Power Functions devices. Both drum winches are powered by a XL-motor, whereof the drive train between the XL-motor and the drum winches passes a clutch-gear box. This clutch provides the 'free fall system' by decoupling the drum winch drive train from the XL-motor. Although this systems works fine, it is very sensitive for distortion of the superstructure and 'free run' of all axles and gears.
Directly under the gear-box at both sides a medium motor is located, connected to a single output of an IR-receiver; as such they run synchronized and drive together a single drive train with 2 worm gears that provides the swing of the superstructure.
The rear drum winch is powered by a single medium motor, located 'upside down' between the 2 XL-motors. Its function is to raise/lower the green 'A-frame' via a double rope system.
Below the rear drum winch, a rechargeable battery box is mounted. The choice for the rechargeable battery box a logical one: its weight and size are less compared to the standard battery box (as used in the undercarriage). As well, the 3 IR-receivers are located in this area. There was still enough space left under the XL-motors to deal with all the wires!
Boom & A-frame
As mentioned, the main boom exists of multiple sections. A boom foot connected to the superstructure, an extension section and a boom head. The length of the main boom is approximately 110 studs or 7x beam 15L, being 22 meters in original scale.
An green A-frame is mounted on top of the boom foot. By larger cranes, the A-frame provides momentum being able to lift the main boom.
The boom head consists of a main pulley on the top, and a smaller pulley somewhat under the top.
Note: the original Liebherr HS 875 HD has an allowed maximum 30 meter boom by dragline operations. Unfortunately I had to compromise the boom length for this model; I tried a longer boom but that ended up in too much stress on key LEGO® parts and easily tipping of the whole crane itself.
Bucket
The dragline buckets of the ESCO Corporation (developer and manufacturer of highly engineered wear parts) are used as an example. That is why the bucket has a red color touch.
Providing the bucket's free movement, both the front and rear drag chains can pivot without touching the bucket. For the rear chain this is achieved by the beam spreader bar that is 1 stud wider than the bucket itself. The front chains are linked to a 3L bar, mounted on the outside of the bucket. LEGO® bionicle chain links appeared to be the most realistic chains for the bucket.
The 8 red teeth (bionicle) can be quickly replaced if one is broken by just snapping of the axle of the bucket, just as being the case in real life.
It took a while to figure out the best position to fit the front drag chains to the drag line; it appeared to be 47 cm measured from anchor bracket (red 2L axle). In this way the bucket is able to drop vertically.
Both lines can be easily disconnected from the bucket.
Crawlers & Undercarriage
The undercarriage was a relative easy exercise. The 'new' LEGO® track system was used to develop the crawlers. Each crawler is driven by a large motor. A standard battery box is located beyond the L motors. The IR-receiver is mounted as much as possible to the outside to collect the signal easily.
When I designed and developed the crawler crane, I was afraid the IR-receiver's ' line-of-sight' was distorted by the superstructure above it, resulting in loss of remote crawling functions. Suprisingly, it turned out, even outdoor; working just as intended!
Superstructure
Most of the time was spend to build a sturdy superstructure and to find locations for the many Power Functions devices.
Multiple 5x7 and 7x11 'open center frames' are used to deal with the forces applied by the boom and the weight of the Power Functions devices. Both drum winches are powered by a XL-motor, whereof the drive train between the XL-motor and the drum winches passes a clutch-gear box. This clutch provides the 'free fall system' by decoupling the drum winch drive train from the XL-motor. Although this systems works fine, it is very sensitive for distortion of the superstructure and 'free run' of all axles and gears.
Directly under the gear-box at both sides a medium motor is located, connected to a single output of an IR-receiver; as such they run synchronized and drive together a single drive train with 2 worm gears that provides the swing of the superstructure.
The rear drum winch is powered by a single medium motor, located 'upside down' between the 2 XL-motors. Its function is to raise/lower the green 'A-frame' via a double rope system.
Below the rear drum winch, a rechargeable battery box is mounted. The choice for the rechargeable battery box a logical one: its weight and size are less compared to the standard battery box (as used in the undercarriage). As well, the 3 IR-receivers are located in this area. There was still enough space left under the XL-motors to deal with all the wires!
Boom & A-frame
As mentioned, the main boom exists of multiple sections. A boom foot connected to the superstructure, an extension section and a boom head. The length of the main boom is approximately 110 studs or 7x beam 15L, being 22 meters in original scale.
An green A-frame is mounted on top of the boom foot. By larger cranes, the A-frame provides momentum being able to lift the main boom.
The boom head consists of a main pulley on the top, and a smaller pulley somewhat under the top.
Note: the original Liebherr HS 875 HD has an allowed maximum 30 meter boom by dragline operations. Unfortunately I had to compromise the boom length for this model; I tried a longer boom but that ended up in too much stress on key LEGO® parts and easily tipping of the whole crane itself.
Bucket
The dragline buckets of the ESCO Corporation (developer and manufacturer of highly engineered wear parts) are used as an example. That is why the bucket has a red color touch.
Providing the bucket's free movement, both the front and rear drag chains can pivot without touching the bucket. For the rear chain this is achieved by the beam spreader bar that is 1 stud wider than the bucket itself. The front chains are linked to a 3L bar, mounted on the outside of the bucket. LEGO® bionicle chain links appeared to be the most realistic chains for the bucket.
The 8 red teeth (bionicle) can be quickly replaced if one is broken by just snapping of the axle of the bucket, just as being the case in real life.
It took a while to figure out the best position to fit the front drag chains to the drag line; it appeared to be 47 cm measured from anchor bracket (red 2L axle). In this way the bucket is able to drop vertically.
Both lines can be easily disconnected from the bucket.
Crawlers & Undercarriage
The undercarriage was a relative easy exercise. The 'new' LEGO® track system was used to develop the crawlers. Each crawler is driven by a large motor. A standard battery box is located beyond the L motors. The IR-receiver is mounted as much as possible to the outside to collect the signal easily.
When I designed and developed the crawler crane, I was afraid the IR-receiver's ' line-of-sight' was distorted by the superstructure above it, resulting in loss of remote crawling functions. Suprisingly, it turned out, even outdoor; working just as intended!
The dragline is based on the original Liebherr HS 875 HD hydraulic crawler crane, including 2 main winches. The crane features a boom being extendable with multiple sections. The crane equipment is modular designed to operate as a crane, dragline or clamshell.
The working range of the main boom is between 15 - 82 degrees with a maximum length of 50 meters.
The total weight of the crane is approx. 93 ton.
The color scheme is based on the famous Dutch Construction Company 'Royal BAM Group', which history goes all the way back to 1869 when it was started as a family company.
BAM refers to 'Bataafsche Aanneming Maatschappij'.
The working range of the main boom is between 15 - 82 degrees with a maximum length of 50 meters.
The total weight of the crane is approx. 93 ton.
The color scheme is based on the famous Dutch Construction Company 'Royal BAM Group', which history goes all the way back to 1869 when it was started as a family company.
BAM refers to 'Bataafsche Aanneming Maatschappij'.
