Dear all,
I have built 3 working scale models of cranes, a Manitowoc 4100W with Ringer (1/25), a 4600 S-5 (1/25) and a Krupp 180GMT (1/20) with counterweight truck.
In 2006 I started on a scale model of the Liebherr LTM1800 expecting about 10 years to complete it. I chose this crane because it has so many possibilities, both telescopic as lattice boom, derrick mast, etc.
The axles; it has 16x8 drive and I wanted to do this for the model as well. Steering is on 6 axles. I bought the differentials (Traxass) and built the axles around them. This saved me a lot of time and they turned out pretty good. The only disadvantage was that these differentials are a bit bulky for this scale.
I put a lot of strength (and thought) in the central part of the carrier frame, because all the forces are going through this part. It also needed to accommodate 2 drive axles and the slewing ring and the electrical controls need to go through the slewing ring to the upper.
The slewing ring is almost an exact copy of the real one, same principal with the motor located in the rear of the carrier. It has an optional quick disconnect which raises the upper a bit, but makes it very easy to take the upper off. There are only a handful of real ones with this feature.
I made the outriggers of steel, brazed together for strength. The outriggers have small geared motors inside and work with a spindle.
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Here is a video of the outriggers:
http://www.youtube.com/watch?v=i1kol40B3ow
Most of the drive line is finished. It has 16x8 drive, a transfer box with 2 speeds and a central differential. I still have to make the main gearbox. The steering is done with a servo in the front. I am not sure if this servo is strong enough. It might need a stronger one.
This picture shows the working outriggers and the upper almost finished. The upper is made entirely from AL and the winches have individual motors. The winches can be lifted out easily, like the real one. I choose to leave the second winch out and use the space for electrical stuff. I managed to make a device that pushes the A frame up till it is in a working position.
And this one shows the A frame being raised:
http://www.youtube.com/watch?v=mLI-NwKSGx4
Kerst