Help with AC motor from turntable

Other Hardware Motors, Mechanics, Power and CNC
1

I'm currently working on a project exploring the combination of sound and play in which a camera is reading the color of objects on a spinning turntable and playing a unique sound bite in regards to the hue of this object. This will allow users to arrange colored objects and/or draw colored patterns on a spinning turntable to create unique beats. I'm using processing to analyze the color and play the sounds; all of the code is working in that sense.

You can see more information at:
http://clchappelle.com/work/milestone/ (there's a short video at this link)
http://www.clchappelle.com/work/currentprojects/ (there's a short description and some photos at this link)

I'm currently having some troubles with the physical turntable and was wondering if I could get some help. The turntable that I am using can only be slowed down to 32 rpm or so. In order to allow time for processing to accurately read color and play the correct sound I need to slow the motor down to around 10 or 15 rpm.

This is an image of the inside of the turntable and the motor that is being used:

According to the label an AC 27v motor controls the turntable. Is it possible to attach this motor to an arduino and program it to run at slower speeds? Will I need a motor shield like this one? RadioShack.com Official Site - America's Technology Store

I appreciate any help/comments. I've made several projects in processing, but have very little experience using an arduino (I've only done a couple tutorials). I do, however, currently own an arduino, some pots, wires, etc. I can easily pick up a motor shield if that is necessary.

Any help is appreciated!

2

Can we see a photo of this label? 27VAC sounds implausible to me.

3

The motor shield will probably not drive AC motors correctly.

You could also replace the motor with one that give you the right speed. (Typically, those will be DC motors, though, so some source of DC power is needed)
Here's a nice and slow one: http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=253323&

4

I can't see the mechanics well enough. What, in that picture, is the motor? I don't see a turntable just a bunch of boards and plastic.

Is it belt drive? Gear drive?

5

Sorry about that, this is a picture of the inside of the turntable. The grey square with rounded corners in the center holds the motor, which controls the turntable. This is a direct drive turntable

Here's a closer image of the motor:

6

OK. That grey square thing isn't immediately recognizable as a motor. It's just a grey square. What's under it? I'm guessing it's a 3-phase AC motor like a hard drive motor, but it might be a shaded-pole motor if there is some kind of speed control. Are there any gears under it?

If it's a shaded pole motor or brushed DC motor, you can slow it down by 'dimming it'. If it's an AC synchronous motor or 3-phase motor, you will have to change the driver electronics frequency.

What's that thing to the bottom left a bit? That DOES look like a motor, or transformer or solenoid.

7

Is it a direct drive motor or is there a gear drive / belt drive? If the latter, it would be an easier alternative.