I really like the concept and think you've done a great job. My favourite part is the mechanical hand as I feel you've got the proportions better on that one. If I was doing this piece I wouldn't have the mechanical hand overlapping the sheets in I don't think I would have included the sheets in the frame at all, as I feel it detracts from the overall feel of the image as it's a very deep shade of blue. With regards to the other hand I feel as though the fingers are too small compared to the palm part of the hand. It looks like you have the drawing skill you just need to study up a bit on composition a little. Photography is a good one for that as it get's you to focus what's in the frame more.
Hope this helps some what. BTW I wouldn't consider you a beginner based on your drawing skill as it's evident that you're somewhat practiced.