Let me introduce myself: I'm 49 years old and have been playing a lot with lego when I was a child. The good old time, when there were no sets, just bricks. Last year I decided to buy the mobile crane (#42009). My first lego set since over 30 years. I build both models and was really impressed by the complexity and how everything works together.
Early 2014 I started building my first moc. A straddle carrier. The construction needed some planning, cause I've only own a limited number of bricks. So I build one edge, count the bricks and made three bags with the same bricks for the other edges. The most complex part of the straddle carrier is the gearbox. At first I implemented the function to move the spreader left and right. Then I added the ability to drive the straddle carrier forward and backward. And last but not least I build a worm gear with a winch to move the spreader up and down. The last one was tricky, cause the spreader tends to be crooked. So I changed the cable run and added some gears. After four months I finished my work:
And cause I like video editing, I've made a small video showing the straddle carrier in action which you can find at YouTube:
You can find more picture at Instagram:
http://instagram.com/libertyschulz
And, if you like my model, you can support it a Lego Ideas:
https://ideas.lego.com/projects/65186