After years of building heavy equipment I start building the Menck and this Liebherr in 2003. The Liebherr was ment as carriage for the
MAN tipper truck but, off course, also fitted on other trailers. My aim was to build a fully functional model which can also drive.
For years I wanted to build a tipper truck with a drawbar trailer which is loaded with some light equipment. When I was building the MAN tipper truck
it was already definite I would build this Liebherr excavator too. I haven't build something similar before and you always have to look after something new.
Building the model
On the Liebherr website I started searching for the documentation necessary of this machine. At that time the A904B was still available but not long after it was
successed by the A904C. The operators cabine is the same as the one on the R974B which I built in 2000. But comparing to this
heavy tracked excavator I really wanted something which you can play with. Also inspired by the JCB excavator of
I started building the undercarriage. Allthough I'm not very charmed with the
I had to use these for the drive train and the steering mechanism. To have enough power I used two
of those motors for the drive train. Normally I place a differential in between of the motors two compensate the difference in RPM between both. But due to lack
of space I had to keep this away. Off course on the axle itself I placed one. The non-steered back axle is driven and the powering is placed at the back. A
third mini-motor is used for steering the front axle and is placed right in front off the other motors. Because this model is relatively small you you're obliged to
build in a compact way especially when you put so many technical functions in it. But, off course, this is the big challange. Above the steering axle I placed
the drive for the turn table which is driven by two old style 9V motors. Because the motors are placed on
both sides of the frame this time I had some space left for a differential. To keep the drive smart and simple and to use as less gears if possible I could build
everything quite compact and next to this all motors are covered with other LEGO pieces so you can't spot them.
This machine is to be delivered in various configurations; with two or four support legs, with a blade or with a combination of both. At first I chose for the version
with two support legs but later on I added a blade as well. Both the support legs and blade are operated but pneumatic cylinders.
Because I wanted to use cylinders from one piece I let the digging arm to be operated by electric motors instead off pneumatic cylinders. The digging arm could
be quite heavy and pneumatic might not be powerfull enough.
I already had some experience with the loading crane of my MAN and on this model it worked more or less. And after all it would be a big bunch of hoses
I had to use because you have two connection points on each cylinder.
The drive of the arm itself is placed in the back of the machine. Two old style 9V motors are driving a reel
and the arm is lifted by a rope. With some hoses I covered this rope more or less. Obviously I used a diffential in between both motors because the space
was big enough. The drive of the stick is just like the boom's but this time it's powered by a mini-motor which is build in the boom.
The boom is four studs in wide just like the mini-motor. With yellow foil I covered the grey parts of the motor. For this drive I used fishing rod which just leads
underneath the cylinder and therefore it's hardly visible. The bucket is also brought into movement with the help of a mini-motor and on its turn this one is placed in the
stick. Eventually I tried to use a
for this purpose but this one slips. The bucket is from the wheeled loader of set
It's quite funny to use this kind of 'pre-fabriced' parts. But I had to adapt the bucket to make it suitable for an excavator. Off course without modifying the
I made from a piece of plastic pipe and taped it up with some yellow foil. To have it compatible with LEGO I modified some 2x2 plates and glued them onto
the cylinders (I used old pieces off course). For the extended part I took some aluminium pipes. You might mention why I didn't used the large cylinders from the
The answer is quite simple; when I was building the Liebherr this set wasn't brought out yet. But after it's release I didn't buy a copy so I haven't changed it either.
As already said the operators cabine is similar to the R974B ones in practical. It can be removed from the machine but I didn't make other equivalents of this
machine (like a material handler on which the cabine is placed in a higher possition). The ballast block
at the back can be disconnected as well. To keep the body in balance I used some
Actually a model like this is never finished and regularly I changed some things. The drive train, the turn table etc. etc. I think dismanteld everything once
to make it better or because some small gears were broken. The sticker I made myself and throughout the years I had to add some new ones because they
The nicest part is always when to have the opportunity to demonstrate a model during events. Off course you can build huge MOCs but my opinion is when
it's quite static it gets less attention. This Liebherr is compact and the motors are powerfull enough to operate it. But the disadvantage is sometimes gears
are breaking when you often play with it. This is you're all doing it for. In December 2007 I dismanteled the Liebherr eventually to use the pieces for a new
model. In 2007 I didn't took my Liebherr to modelshows anymore and I broke off the MAN in 2006 already. The Liebherr was also used as a load for the
Scania T114 but this model is also dismanteled in 2007. It also fitted on my
Actros of Mammoet as you can see on the picture. It's time for something new again and the model actually didn't fit to my todays
standards. This means you're grown again and new challanges are in front of me.
Here's a short video of the Liebherr and its functions. It's quite an old video taken with a camera without a microphone.