Hi friends I have made an excavator along with one of my friends. It's surely not that large to move a mountain but a very small scale model just as my classroom hydraulics project. It works nice. You can see it here working: But problem is that didn't make it automatic i.e i operate it by pressing against pressure cylinders by my hand. So, it's a bit unprofessional. This is becuase it didn't get so small and yet powerful pumps to force fluid in the cylinders. I was wondering how to make it automatic i.e i just press a buttom for each link and if such small pumps which are powerful enough available or is it possible to make them. Thoughts!