The Motor Is The Heart Of The Machine

The motor is the heart of the machine.  Well, that is how I view it - if the motor stops working then interest quickly wanes.  This was also an easy item to focus on as it is minimally coupled to the rest of the cabinet and it's design.  So, I could research and learn and make decisions on motor without much impact or dependency on the rest of the project.

Disclaimer here and going forward - For a lot of coin pusher parts and components I do not know what the official names and terminology are.  I did find some components on replacement parts web sites and I try to use their terminology.  For other components I have made up names that sound appropriate. So, that is my excuse for inconsistencies when referring to items.

Coins inserted into the machine fall through the coin drop and land on the push platform.  The push platform, continually sliding forward and back, causes coins to get pushed off of it and onto the larger play area.  Looking at different coin pusher videos, both commercial and DIY, the frequency of the platform's movement varied quite a bit and didn't seem to be an influence in general operation.  The push platform's movement is controlled by a motor.

I observed that, generally speaking, there are two ways of connecting the motor to the platform:

• Motor mounted under/above the push platform 
• Motor mounted behind the push platform 

The next decision - what motor?  In my research I found I could buy a commercial machine replacement motor for $80 to $100+.  For DIY machines I found two popular options were automobile wiper motors and microwave turntable motors.

Initially I leaned towards the wiper motor based solely on the assumption that a microwave turntable replacement motor would be expensive.  The wiper motor, however, due to its odd shape and mounting structure would probably need to be installed as a 'behind the push platform' motor.  I struggled with this as I desired the under/above approach.  It wasn't until, out of idle curiosity, did I research microwave turntable motor prices and I was surprised to find them as a very affordable option.  The prices varied from $5 to $30.  I opted for the $5 and decided to give it a shot. (See the Bill Of Material page for more information on this motor.)

It is rated for 4 to 4.8 revolutions per minute.  This is a bit slower than I wanted but felt I could live with it.

It is simple, compact, and easy to mount.  Also, most of the ones I looked at seem to have similar size and shape so if I decide to upgrade to a faster one later it should be quite easy to do.  Here it is in action:

Some observations:

• It took 13 seconds for one revolution
• It seems to have enough torque for this application
• It is VERY quite.  Videos of wiper motors were much noisier.
• As I have noticed in my microwave, each time the microwave starts the motor changes direction.  This motor does the same. This is OK and has no affect on my usage.
• After running for only a few minutes I noticed the casing got a little warm.  I'll keep an eye on this and if it does get hot then I will install a small fan over the unit to help keep it cool.  

Up next:

• Mock up a push platform and see how the motor performs