CAROUSEL
PROJECT SHEET
creation started November 2021

The street organ that I play in public several times a month has been asking for a carousel.  The street organ (Misty) has been good to me and very good to the public so I am granting the wish.  The objectives:

  • The Carousel is to be easily removable so that it does not need to go everywhere.
  • The Carousel will be powered by a 6vdc gear motor, and controlled (start, stop, acceleration, deceleration) by an Arduino microprocessor.
  • It will start operating when it detects (via an audio sensor) that the organ has begun to play.
  • Five carousel animals, all of which go around and up and down.
  • Several ‘passengers’ that ride the animals and that wave to onlookers.
  • There will be room for two sideshows…one to the right and one to the left.

January 12, 2022. Installing the electrics.
Carousel

The electrics package consists of three modules:

  1. The 6vdc gear motor: This motor has been nested in leather (for soundproofing) and mounted under the carousel.  The motor draws just milliamps.
  2. The 6vdc power supply: This module consists of a 6vdc rechargeable lithium battery, a circuit breaker, a digital volt/amp meter, an on/off switch, and the female plugs.  It is mounted under the rear of the carousel and can be easily removed by simply lifting it and pulling it out.
  3. The electrics package includes an Arduino Uno, a DC voltage regulator, a sound sensing board, and an L298P motor control board.  This package is screwed to the underside of the carousel.

As I write this it is January 17 and I’ve got some experience with all of this in ‘real world’.  

As I worked with this in my studio is felt that the motor was too loud.  Outside in the public the motor cannot be heard.

I do not feel comfortable with the sound sensing board that I’ve used so am going to replace it with a different (more expensive) one.  This past Sunday I did perform in public with the carousel.  I had it set to simply run continuously.  Continuous operation is fine, however I continue to want it to start and stop as I play the organ, and as each tune begins/ends.  So I’m going to re-engineer this electrics package.  No rush.  But I will do it.

Regarding battery life: I was hoping that I could keep the carousel running for the full four hours that I am able to perform.  It turns out that the battery will apparently power the carousel for perhaps several days on a single charge.  I’m very pleased about that and am no longer worried about adding the side shows (which will draw addional power from the battery).

 

These power supply components will be placed into the case. January 1, 2022
The electronics package is being breadboarded and tested.  January 9, 2022

The carousel electrics are being packaged. The package will be mounted beneath the carousel. January 12, 2022.

December 17, 2021: The top-end functions.
Carousel


I 3D printed the carousel gear head (see the second image) and am very pleased with the result.  The horses each now move up and down twice per revolution.  The motion is smooth and I believe that it will be reliable over the long term.

As I work with timing I conclude that about 8-10 rpm will be an appropriate speed.  Today I ordered the materials that I will need to create the drive mechanisms.  At the heart of it all will be an Arduino microprocessor.  Two shields will be connected to the processor: 1) an audio sensor, and 2) a motor controller.  When the processor detects that the organ has begun to play, it will accelerate the carousel up to operating speed.  And after the music has stopped it will decelerate the carousel.  I don’t want jerky stops and starts…I want smooth acceleration and deceleration. The carousel will be driven by a 6vdc gear motor through a poly belt.

The carousel animals were purchased as a ‘lot’ several years ago from eBay.  There were about 25 animals in the lot.  They are ceramic.  I’ve refreshed the paint on the five animals that Cheryl (my wife) selected for this carousel.

In the image, you see the carousel mounted in its build frame. The build frame is up high so that I can easily work on both the top and under parts of the carousel.

While I wait for the parts to arrive I will be disassembling the carousel and decorating/painting it.

 

The carousel horses have been fitted to the carousel. They now move around and up and down. December 17, 2021
The carousel gear-head has been 3D printed and works beautifully. December 13, 2021.

December 1, 2021: Being Fitted to the street organ.
Carousel


The image shows where the carousel will be located on the organ.  As you can see there is room to the right and to the left.  I will be creating ‘sideshows’ that will fit into these two spaces.

I created a temporary build stand in my studio that replicates being hung in the front of the organ pipes. The carousel is easily removed.  I will also construct a travel box for the carousel assembly so that it can easily travel without being damaged.

I will be using a 6vdc rechargeable lithium battery (the kind used to power kids’ electric cars and trucks).  Until I have it in hand I don’t know where in the assembly I am going to place it.  I’m hoping that there will be room under the carousel.

The carousel is being fitted to my 20 pipe street organ. December 1, 2021.