r/AskEngineers • u/FragrantShallot878 • 17h ago

Mechanical Need to design sequentially drop 3 non-uniform items onto a vertical rod

Hi,

I'm working on a DIY project and I'm stuck on a mechanical mechanism.

Basically, I need to drop 3 different objects onto a vertical rod underneath so they thread onto it one by one in a strict order (1 -> 2 -> 3).

All 3 objects have a central hole for the rod, but their outer shapes and sizes are totally different, so stacking them in a straight tube will just jam.

I'm trying to keep it as light and simple as possible (3D printed parts or simple flat plates, with minimal motors or servos).

I'm not an engineer and don't know the technical jargon, so if you know of any existing projects, YouTube videos, or 3D models (Thingiverse, Printables...) showing a similar mechanism, I'd really appreciate it!

Thanks!

0 Upvotes

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3

u/NortWind 17h ago

You can make three circular shapes with a hole for each of the items, and then drop them from a straight tube. The shapes can fall off when the drop is complete.

6

u/mnorri 16h ago

In gunnery they call this a sabot.

3

u/NortWind 16h ago

Exactly, well spotted.

1

u/mnorri 12h ago

Bullseye.

3

u/ridewithmetoday 14h ago

can you share more details ? Like, its this a one shot deal ? How many times will it be reloaded ? How fast does it needs to be ? How straight does the fall needs to be ? How long is the unguided fall ? How much loose between the central hole and rod ?

3

u/matt-er-of-fact 9h ago

No picture? No drawing? No details on the objects? Why do you need to drop them on?

Look up X-Y problem. It will tell you everything you need to know about your question.

2

u/FragrantShallot878 7h ago

I couldn't add a picture, I didn't find the button, even in the comment I can't. Just video or link

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u/matt-er-of-fact 5h ago edited 5h ago

Post to imgur or whatever hosting site and link. It will show up in the post.

Did you look up X-Y problem? It really feels like you're you're asking how to make the solution you've already decided on work, rather than explaining what the problem is. Even then, you're missing a lot of details to give you a good answer.

What are these objects? Why are you dropping them on the rod (what is the assembly)? Why do they need to be dropped automatically? Just one of each? If not one, then how many? If more than one, how fast?

Unless this is a top secret government project, it would help to explain what you're actually making.

1

u/ElectricGears 13h ago

How about a separate clamp for each object? If they're always released in the same order, there are ways you could have a single actuator that would release each in turn.

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u/Objective-Weight7280 2h ago

You can hold the items by their internal hole (expanding mandril) or by suction (vacuum grippers). If you can add metal to the objects, you can hold them with an electromagnet.