These are slightly larger dominos than the ones I built for my previous domino machine.
The tiles on the side make them stronger. 💪
I have a feeling they will be put under a lot of stress.
They work!
The dominos are built on top of a base, to make room for the lift mechanism.
I decided to keep it simple and have them fixed to the base on a hinge. (Yes, I know this probably doesn't make them 'real dominos')
Otherwise dominos would be flying everywhere.
They still work.
I decided to add a pin on the side of each domino to aid in lifting them up.
I also added this 2x2 modified plate, to give a stronger connection to the base.
Otherwise the dominos are prone to being pushed off.
These triangle liftarms are great for pushing them back up.
But they interfere with each other. Their movement needs to be constrained.
Time for another pin.
We'll reinforce the liftarm and add a control wheel as well.
Now the lifting arms don't interfere with each other.
I'm using LEGO train tracks to build the ring shape.
The dominos will sit along the outer edge.
Still working! 😀
A ramp will run along the tracks to lift up the dominos.
Not bad, but it will have to move FAST to keep up with the falling dominos.
This ramp is too aggressive.
Time for a lower angle ramp, to more gently lift the dominos up.
Very smooth.
And works well at speed.
Time to build the full ring!
It holds 64 dominos.
Even just watching them fall once is quite satisfying.
Annoying to put back up manually though.
Time to add the ramp.
Manual test. It works!
Actually pretty satisfying to manually control it, but I obviously can't do it forever.
Time to automate.
This central ring will be motorized, with speed controlled by a Mindstorms EV3.
A single domino will be monitored for feedback.
The IR sensor is used to monitor the state of the domino (Up/Down).
The EV3 uses 2 large motors to drive the ring.
I have to manually start the domino run.
This is a simplified version of the speed control logic.
The EV3 measures the time between each state change of the monitored domino.
The goal is for t1 and t2 to be equal.
The speed is adjusted accordingly once pre revolution.
The data is displayed on the EV3 screen.
It also includes total time elapsed and total domino fall count (64 per revolution).
I filmed the EV3 screen on a different run, so the time and speed values aren't accurate,
but it gives you an idea of what is going on.
Approximately 1500 dominos fall every minute.
Which is over 2 million a day!
For this run, the EV3 is running on a rechargeable battery pack,
but it can be plugged into main power to run indefinitely (theoretically).
So far, the longest I've run it continuously has been 6 minutes.
I plan to do a 1 hour test in the coming days, perhaps as a live stream.
So far there have been no operation issues,
but I'll be interested to see what long term performance is like.
I can hold down the middle button to stop the run.
It will speed up the ramp until it catches up to the falling dominos.
Thanks for watching!