It can move autonomously by means of and XL-motor, a switch and a winch that operate the reciprocal movement.


I made picture based pdf-instructions that you can download for free from Rebrickable:
http://www.rebrickable.com/mocs/martijn ... aterpillar
On Rebrickable I also have other Technic based models with instructions that I hope you will like!
http://www.rebrickable.com/designer/martijnnab