Hey All,
Here are my modifcations to the 42009. Really, it is a whole new beast, and I tried to mimic the Liebherr 1500 8.1 mobile crane. Added a jib and weights for stability.
I really tried to enhance the strength of the model. As can be seen from the video and pics on the URL provided, adding strength can be done. It was able to hold my version of the 8070 (around 1500 grams) without problem. However, lifting the model was still difficult; the motor is just still too weak, even with the added help of the mechanical advantage provided by the pulley system. Check it out:
http://mocpages.com/moc.php/388884
http://mocpages.com/moc.php/383148