Advice needed on motor selection / Ardunio board type.

Projects General Guidance
1

Okay, to make a long story (kind of) short, my team and I are building something where we will need a motor. The motor will stand upright and it will be attached to a shaft and plate assembly. The plate will take the place of the bottom of a bucket where golf balls will be dumped. We are making an automatic golf ball tee feed.

So the motor will have to turn this shaft/plate assembly with ~200 golf balls on it (around 20 lbs for the balls + 10 for the plate). So we need a motor that has a reasonable amount of torque, but it also must have a low RPM due to design of the product (~ 6-12 rpm is okay, 8-10 is ideal).

Arduino comes into play because we want the board to be able to tell the motor when to turn on and off. Eventually, a sensor will provide the "on/off" for the design. But for now, the main concern is powering the motor with an Arduino board.

Unfortunately we are all ME's (in school) and don't know too much about motor types and such. Should we get AC? DC? How much voltage is too much? etc... So this is hindering our design since we are unsure of what motor to buy and what board will help us with what we need. Someone suggested microwave motors like the ones on this page:

http://www.repairclinic.com/Microwave-Motor-Parts

But once again, I'm not sure which voltage we would need to execute this and what board would work with it. Can anyone provide some inside as to which motor/board combination would be the best (and preferably the cheapest)? Or at least an idea of how the voltages matter in terms of the board selected.

Also - i noticed the motors on that page just have the two electric leads... How would this be handled in terms of powering it from an Arduino board? Would you have to open the motor and connect some wires from the leads to the board itself? etc...

Thanks for any and all help!

:slight_smile:

2

Microwave carousel motors are AC motors. You can control them with a relay but because of the danger of working with electrical mains I would not recommend them.

A DC Gearmotor that can run on 12V might be a good choice. You can easily turn it on and off with a logic-level MOSFET.

3

A car windscreen wiper motor might be suitable, as JohnWasser said drive it with a MOSFET

4

But for now, the main concern is powering the motor with an Arduino board.

How would this be handled in terms of powering it from an Arduino board?

First thing I think you need to get your mind around is the difference between powering something and controlling something. An arduino is great a controlling things, but it's very poor at powering things other then small leds and other low current components. So for your project you have to kind of make your component choices and decisions in a logic order as in:

  1. First select the motor. If must have the mechanical torque and rpm to do the job, the arduino cannot solve that if it does not.
  2. Once a motor is selected, find out what it's running voltage (and if AC or DC) and maximum current requirements are at full load you will be using it at.
  3. Select a voltage source (power supply) suitable to operate the motor at it's maximum load.
  4. Select the method you will be using to allow the arduino board to control the power to the motor. Do you require variable speed, do you require reversible rotation, or just on/off control? The answers to these will point you in the best direction for how the arduino can be interfaced to the motor to control it under you sketch software. It might be a simple relay or a logic level power MOSFET, or a full blown H-drive motor controller.

Lefty