The Sioux.NET on Track team has made new plans for the layout that will be demonstrated at Lego World Utrecht in 2016. In this article, you’ll find a summary of these plans. Stay tuned this year for some nice buildings and of course, lots of programming!
In the sketch below, you’ll find the basic idea of the layout for 2016:
The main principle remains unchanged: the visitor chooses a candy color (red, green, blue or yellow), train is getting the candy from the candy stock, candy is loaded into the train by the candy crane, train delivers candy to visitor.
Choosing the color
We don’t know yet how the visitor will choose the color, but it will be a rather simple selecting mechanism. Because, after the color is selected, the real fun begins. A crane using a vacuum catcher mechanism (that will be based on the idea of using pneumatic for creating a vacuum, see www.youtube.com/watch?v=SYipV3zKF8I) picks a candy card from the stock. The candy card contains a picture of the candy in the selected color, a digital number and a color scheme for the card reader at the delivery boxes. Something like this:
Up to four visitors can choose their colors in a row. The train will deliver these four candies in one train run. By this means, we intend to increase the throughput of the layout.
Updated candy stock
The current candy rotation stock will be updated. It will not longer be a rotation stock. The containers will be automatically filled with the candy by a feeding mechanism. After filling up, the container with candy is transported by the conveyor system to the crane pickup position. Since four visitors have selected their candy color, four containers need to be transported to the pickup location.
Updated candy crane
One of the problems of the previous crane, was the fact that the candy often fell out of the grabber. So, we decided to change the grabber and that it will pick up the complete container and not only the candy. This update can be seen on our Youtube channel:
Since the candy crane had to operate continuously for about seven hours, it needed to be attached to a power supply. The cable of the power supply sometimes got stuck which caused the crane to stop working. A power chain system was added to prevent the cable for getting stuck. This update can also be seen on our Youtube channel:
The same power chain will be made for powering the second EV3 that moves the frame back and forth..
Another problem was the positioning of the hoist. A color sensor was used to position the hoist at the pickup position (white) and the four loading positions (red, blue, yellow, green). In the test environment, the positioning of the hoist worked fine. But if the light was too bright (and that was the case at Lego World), the blue color was too often interpreted as white which caused the system to fail. For the 2016 version, we only need three positions: one pickup position and two loading positions. The color sensor is replaced by two touch sensors and that is also visible on the previous video.
Last, the crane has been rebuild with (light bluish) gray bricks that gives the crane a more robust look. See the LDD drawing below for the result.
What we have to find out, is how we will position the crane correctly above the four wagons that will be loaded with the containers. The positioning system with the RFID tags is not accurate enough for this purpose.
A new delivery station will be made containing four delivery boxes. The containers will need to be moved from the wagons to the four boxes. In that process of movement, the candy needs to be separated from the container.
At the screen, the visitor can watch the progress of his candy card (by the number). When the train arrives, the four visitors can feed their card into the card reader that opens the corresponding delivery box. Candy delivered.
How the candy will be separated from the container has to be worked out, but it probably will be as simple as a filter where the candy falls through and the container is moved back to the stock location.