In my engineering class we must make a machine that can sort 15 marbles with 3 different types in less than 2 minutes. I plan on having one marble go over/under a light sensor with a flashlight on the opposite side so it can read its reflection, then have a gear with three cups spin according to what the light sensor value is.
Do you think that the light sensor will be able to read the value and spin in less than 1 second? Or should I put something to stop the marble while it is being read?
The light sensor should not be a problem. Depending on the system you use this should work in milliseconds or less.
The mechanical spinning of the cup will probably be the limiting factor. 1s may be possible but balls probably drop faster than this if you don't have a gate. I would probably add a gate or use a different method to control the balls.
The other obvious issue to me is how are the balls flowing in. If they are near continuous do you need to be able to separate two balls of the same type.
In general, you should try and design a flexible system so that you can add and remove things like a gate if they are needed or not as there will likely be some issues you haven't thought of yet.
A sensor's switching frequency will usually be in the order of milliseconds, so it definitely won't be a problem. However the highest delay you will have in the system is turning to the right cup to dispense the last marble that was sensed. Attach a two bit absolute encoder on the spinning gear to always find the shortest path to the right cup.
As for the marble feeder you can use a vertical tube stack of the marbles to be sensed. Two gates can be used along the tube feeder, one that will dispense the marbles one by one from first to last to a chamber for them to be sensed, and a second one to dispense it in the corresponding cup.
This task should be a fast one to solve using this setup. Hope this helps!
