Good morning All!
I have a theater prop project that I'm just starting to think about and work on developing a design. It's going to be a realistic slot machine with mechanical spinning reels, coin drop, functional lever, etc... and lots of lights.
The lights and most of the mechanism I have ideas for but the one I need some thoughts on are the motors/mechanisms for the spinning reals.
I'd like to come up with a way to having the reels spinning and then have them stop at very specific symbols... so I'm thinking some sort of motor maybe with an encoder on it?
Looking for suggestions to start.
Robert
Prop Slot Machine
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Please be positive and constructive with your questions and comments.
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adafruit_support_bill
- Posts: 88144
- Joined: Sat Feb 07, 2009 10:11 am
Re: Prop Slot Machine
The simplest way to achieve precise position control with 360 degree rotation is with a stepper motor. A geared DC motor with an encoder is another reasonable option.
Since steppers move in discrete steps, you can precisely control the degree of rotation by counting the number of steps taken. Unless there is danger of the motor stalling (unlikely in your application) precise positioning can be achieved easily and with high reliability. The one additional thing you would need is a sensor to detect the 'home' position on power-up. This can be a simple reflective or slot-type photodetector
https://www.adafruit.com/product/3930
https://www.adafruit.com/product/3986\
Gearmotors with encoders give you position feedback as the motor is moving. You would need to implement some sort of proportional control algorithm to reliably stop the motor at the desired position. Absolute position encoders are quite expensive. Quadrature encoders are more affordable, but only give you direction and relative rotation. With a quadrature encoder, you would also need a home-position detector as with the stepper.
https://learn.adafruit.com/adafruit-mot ... tion-guide
Since steppers move in discrete steps, you can precisely control the degree of rotation by counting the number of steps taken. Unless there is danger of the motor stalling (unlikely in your application) precise positioning can be achieved easily and with high reliability. The one additional thing you would need is a sensor to detect the 'home' position on power-up. This can be a simple reflective or slot-type photodetector
https://www.adafruit.com/product/3930
https://www.adafruit.com/product/3986\
Gearmotors with encoders give you position feedback as the motor is moving. You would need to implement some sort of proportional control algorithm to reliably stop the motor at the desired position. Absolute position encoders are quite expensive. Quadrature encoders are more affordable, but only give you direction and relative rotation. With a quadrature encoder, you would also need a home-position detector as with the stepper.
https://learn.adafruit.com/adafruit-mot ... tion-guide
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BURevisfan
- Posts: 31
- Joined: Wed Oct 17, 2018 4:05 pm
Re: Prop Slot Machine
Thanks adafruit_support_bill!
After I posted this I started looking further at products and was looking heavily at the stepper motors as well. I hadn't thought about the homing sensor but it makes perfect sense. Thank you very much!
Robert
After I posted this I started looking further at products and was looking heavily at the stepper motors as well. I hadn't thought about the homing sensor but it makes perfect sense. Thank you very much!
Robert
Please be positive and constructive with your questions and comments.