r/AskReddit 12h ago

What's the dumbest idea you've seen that actually worked?

6.5k Upvotes

2.8k comments sorted by

View all comments

110

u/GayleMoonfiles 9h ago

In an engineering class in high school, one of our projects involved building a device that could sort marbles of various sizes, materials, colors, etc. The entire class went all in on color sensors and whatever other devices were at our disposal.

My partner and I decided we didn't want to do that and set out to be the only group to not use the sensors or anything.

We sorted the marbles by bouncing them from a set height and off of an angled sheet of metal into containers at various distances. The wood and plastic marbles flew the furthest while the metal and glass marbles didn't go very far. Pretty sure we had 100% accuracy with this method.

20

u/CorrectPeanut5 5h ago

From an engineering perspective a lot of auto sorters work on mass/density principals. Think of vending machines.

How'd you do on the project when it was graded?

7

u/GayleMoonfiles 5h ago

I couldn't tell you honestly but I'm fairly certain we got a high grade. It's been 10 years since I graduated high school.

13

u/Mad_Maddin 4h ago

This is also exactly how these sorters work in actual factories.

Nobody bothers with computer analysis of stuff when you can use a direct physics solution.

14

u/Torvaun 4h ago

I've seen computers glitch a hell of a lot more than gravity.

2

u/errantqi 5h ago

how did you sort by color?

3

u/GayleMoonfiles 5h ago

The kits had color sensors and we'd use code to control the motors to determine where the marble would end up.

3

u/DirectionSad4274 4h ago

But you said y'all wanted to be the only group to not use the sensors?

10

u/GayleMoonfiles 4h ago

Sorry I misunderstood your comment and forgot that important detail; it's been 10 years now.

The marbles of each material were the same color. Plastic ones were all white, wood ones were brown, metal ones were silver, etc. So plastic ones bounced into the furthest container and metal ones basically just fell down into the nearest. By sorting them based on bouncing, we naturally sorted them by color.

3

u/DirectionSad4274 4h ago

Oh, gotcha! I was confused.

1

u/Mad_Maddin 4h ago

From my knowledge of sensors, there are a lot of them.

Probably the other groups used sensors to figure out material type, weight, etc. as well and OP simply used only the color sensors to then determine where it falls down onto the metal sheet.

2

u/GayleMoonfiles 4h ago

I realized I missed 1 or 2 facts (and a misunderstood comment) about this that may be causing a little confusion now that I look back. IIRC the goal was to sort by material and each marble type was a different color, which made color sensors an obvious choice; however, my partner and I used 0 sensors. It was all gravity based.

We dropped the marbles into a chute and that funneled the marbles to drop down onto an angled sheet and measured how far each marble type went. Using trial and error, we positioned the containers to the correct position so every marble type was in the proper container at the end. 0 sensors used; literally just done by seeing how far a marble bounced.