I have tried to make motorized Lego switches for some time now, but I just can’t seem to get the to work with any reliability. Lego train switches are, in my opinion, horrible. They are extremely stiff to actually switch and gives a horrible cracking noise when you do and even then they aren’t too stable anyway.

There are a lot of nice solutions out there, but I seem to have a problem that others don’t and that is that the ‘floor’ on the switching case gives out. I found this solution: Youtube and modifying it for my purposes (M-motor) was very simple, but it started to fail quickly when the floor gave in and the gear rack flew out of the back rather than changing the switch.

After some testing and constructing I got it working. However after all my six switches were built, it turned out that the only one working was the first one. Back to the drawing board…

I reconstructed the switches to use pneumatic cylinders instead. I’m not sure how to control them yet, but I am happy with the result on the switches. Even though it is a bit too big, at least it doesn’t sound like the switch is going to die every time it is used and I like that.

Download ldr here: ldr