Event Tutorial: "Plinko" Board

Plinko Board Overview

For the third event in our Rube Goldberg machine, we drew inspiration from the Price is Right game "Plinko" where an object is dropped down the side of a surface and its movements are manipulated by a series of posts which make the movement of the object somewhat unpredictable. Here is a step-by-step guide as to how our own personal Plinko board based upon the positioning of each post, the delivery points at the end of the board, and delivery method of the object.

Positioning of the Posts

The positioning of the posts had to be taken exact measurements as the marbles that would be used in this event to be able to move between each adjacent post on the board. Keep in mind, this is most painstaking and time consuming portion of this build. To make sure these post were the proper length away from each other, the first two rows need to measured using whatever object your wish to use on your Plinko board. You should mark each and every place a post will be planted as well as using your desired object as a reference. The second row should have the posts positioned in the center of the spacing of the of the previous row so that when the object is dropped it will make contact with a post and manipulate its direction. Again, keep using the object you are using as a reference so that the spacing between adjacent posts are just enough for the object to pass between. Once the first two rows are completed, you can now draw a grid using those position on the board and making sure every other row has the same post positioning as the previous row. For instance, odd numbered rows will have the same horizontal positioning and also even numbered rows will have the horizontal positioning as well. But do keep mind of the vertical positioning of the rows as the object should be used as a reference to make sure it will fit between the spacing of adjacent rows. 

Once this grid is sketched out, you can begin using whatever materials you are using as your posts. The posts should something straight and cylindrical for optimal results. In our case, we used cut up pieces of wooden chopsticks as the posts for our Plinko board. Bore a hole where the grid lines intersect for that row using your material and glue it into place (we used super glue for this as it quickly and held up well once dried). Be sure to check the spacing of each post you object to ensure it will fit between the posts and reposition them when necessary; a finished Plinko board can be seen depicted below. Once you have all the posts in place, you can move on to the next step of the process.

Endpoint/Delivery of the Object

For this portion of the Plinko board, you can do one of two things; you can have the object fall into a singular delivery point or have the object fall into one of a number of delivery points. For our Plinko board, we had a singular delivery point at the end of the board because we need this event to reliably do a single action. However, if you want to add a randomness and chance to your board, you opt to create multiple delivery points for your object to fall into at the end. Each delivery point should have an angled surface that can coax the object to a specific delivery point. In our's, we had two sizable angled surfaced that would ensure that objects we were using would be consistently delivered to our singular delivery location (which can be seen in the image below).

Object Delivery Method

Object delivery can be done a number of different ways and it really depends on what you're trying to do with your Plinko board in general. In our case, we opted to do a delivery method that was generally consistent with way the objects were introduced to the Plinko board as it did not really matter where the objects were dropped being that they all end up at the same, singular delivery point. A cup on a hinge was created so that the objects could be introduced to the Plinko board by a previous event on our Rube Goldberg machine (image of the delivery method can be seen below). Consistency was key in our case, but if you wanted to add a bit of randomness to your Plinko board, you can develop some method of making that delivery a bit more up to chance by having the object fall in a random position on the board. This is one portion of the Plinko board that can be developed based upon your needs of what you want it to do exactly (do you want it to be consistent or randomized?).