Lego Monorail EV3 – Automated Switch

A monorail without a switch track is not a real monorail 😉

I have been working on an automatic switch for the Lego Mindstorms EV3 monorail. The idea is that there will be a monorail track on our layout with two reverse loops. The loops will each have a switch and the train will need to set the switch in the right position. One reverse loop will be at the delivery station, where the empty containers can be loaded onto the monorail. And the second reverse loop will be at the Candy warehouse, where the empty containers will be dropped. For this year, the (un)loading of the empty containers will be manually. It just saves time to walk between the two locations with the empty containers. Yes, I know this sounds lazy and yes, it is.

In the video below, you see version 1.0 of the automated switch. Currently, the switch is powered by a PF motor. The train was simply programmed to run and switch direction when it noticed a the green tile (on the left, not visible in the video), a red or a yelow tile. Meanwhile, I was operating the switch with a PF remote control.

The next update will be a finished reverse loop, including a second EV3 that controls the switch. The train-EV3 will communicate with the Switch-EV3 to set it in the right position.


Switch mechanism upgraded to EV3 L-motors

As mentioned in the article about the “Plans for Lego World 2015”, the switch mechanisms will be upgraded to the modular version. We use the L-motors since we have plenty of these left. This is how it looks:Upgrade switch mechanisms to EV3 L-Motor

We have four of these mechanisms: three for the marshaling yard and one for the delivery station.

Many successful candy deliveries @Lego World Utrecht 2014

At Lego World in Utrecht, our two trains have delivered many candy sweets to the visitors.

Continue reading “Many successful candy deliveries @Lego World Utrecht 2014”

Modular switch drive with PF, EV3-M, EV3-L or NXT-motor

Our track layout uses automated switches. The current version that we are using (three in total) is based on the NXT motor. Using a (NXT) touchsensor, the PC application can determine the ‘status’ of the switch (i.e. in which direction is the lever positioned):

Automatic Switch, based on NXT motor

Since we will need four switch drives and based on the EV3 (so it can be controlled by one brick), I thought it would be a good moment to redesign the drives.

I came up with a modular drive system. I designed a ‘fixed’ part without the motor that converts the rotation into the lever movement. And four different motor modules that can be connected to the axle:

  1. Based on the PF motor
  2. Based on the EV3 M-motor
  3. Based on the EV3 L-motor
  4. Based on the NXT motor

Train switch - Modular

I am going to design a separate module for reading the lever position, one based on the EV3 Touch sensor and one based on the NXT Touch sensor.

If you want the building instructions of these modules, please do not hesitate to contact me.