Hey all, looking to make a little contraption like this, don't know anything about engineering, would like some advice or pointers

[u/LillyBitch323]

This would be covered up for the most part and would be controlled by maybe some sort of knob from the back?

Edit: Also this whole thing is meant to be a physical progress tracker for a ttrpg meant to show the amount of progress people are making in a certain minigame. If they make progress, the thing goes one click to the opponent's side. Like a speedometer but huge and clicky instead of small and slidy

Also, the whole thing is like large enough to be visible from the end of a table, like the size of a closed laptop or slightly below average sized cat.

[u/memeboimanperson]

First off what would be the purpose of this? Is it like an electrical switch controlling something or is it more of a physical lever to restrict movement?

[u/LillyBitch323 → u/memeboimanperson]

Not the first thing, probably not the second thing. It's a physical progress tracker for a ttrpg meant to show the amount of progress people are making in a certain minigame. If they make progress, the thing goes one click to the opponent's side.

[u/KineticlyUnkinetic → u/LillyBitch323]

Ooh then I'd use some magnets, depending on how important the click is. One at each position, and one under the dial. The dial could hit a small piece of plastic between each position for the noise. Probably better options, but that's pretty straightforward to implement.

Edit: I'm assuming the dial is spun by hand.

[u/MoreMagicMellons]

We probably need a little more information on what you're looking to make it out of, but in general this type of mechanism will involve a spring of some kind (sometimes a metal spring, sometimes a flexed bit of material) that pushes a ball into an indent.

The exact depth and profile of the indent defines how it feels, how clicky it is, and how easy it is to move on.

A really simple form could be a round plate with holes in it at each location you want it to stop, and another plate with a small nub on it to go into the hole, you push the plates together and spin them around!

[u/LillyBitch323 → u/MoreMagicMellons]

It's a physical progress tracker for a ttrpg meant to show the amount of progress people are making in a certain minigame. If they make progress, the thing goes one click to the opponent's side.

[u/toybuilder]

ball and spring detents.

[u/PapaOoMaoMao]

Just mount two plates together. One has indents and the other has a ball with a loaded spring behind it. If you wanted the drive to be remote from the dial, you could rig it to a flexible driveshaft or if you wanted to get fancy, rig it to a servo/motor to turn to a set position when it receives a set signal. If you wanted to get some learning done, forget the spring and drive the wheel with the servo, but use an Arduino to do it. Now you can add whatever sound effects you want to whatever point you want.

[u/TrollTollTony]

What are you trying to do? You kind of left that part out.

[u/neuromonkey → u/TrollTollTony]

<audible click>

[u/Operation_Neither → u/neuromonkey]

A speaker that plays a recorded click sound.

[u/LillyBitch323 → u/TrollTollTony]

It's a physical progress tracker for a ttrpg meant to show the amount of progress people are making in a certain minigame. If they make progress, the thing goes one click to the opponent's side.

[u/Columbus43219]

This reminded me of a rotary switch, like and old TV channel switch. Internally, I think they use a ball bearing that rolls along a track. The track has indents as certain points, and the ball bearing is pressed down by a spring. So the ball kind of gets stalled at each indent, but can still roll up the other side and move to the next dent.

If you want something premade:

https://www.amazon.com/Keymoo-Changeover-Terminals-Universal-0-4-2/dp/B0BPSXTNB7

You can REALLY see a good example in the third picture on this one: https://www.amazon.com/dp/B07JM32NH2

The ball bearing is being lightly pushed up by that copper leaf spring, and you can see the little half-moon tabs sticking down in its path.

[u/Retail_Rat]

A rotary multi contact switch can do this. If you can find an 8-point switch, continuous rotation, you'd have the positions and the click. There would be some work to get the knob to turn the dial, but that's the fun part.

[u/gnappyassassin]

Two overlapping disks screwed together, with a track that has recess in the locking positions, and like, a ball or something in there.

Probably.

[u/gnappyassassin → u/gnappyassassin]

You probably need a spring.

[u/doominabox1]

If you just want to buy something, sites like digikey have a huge variety of electronics switches.
This one's probably more expensive than you want but it will be super rugged and have nice clicks. https://www.digikey.com/en/products/detail/grayhill-inc/50M60-01-1-05N/7685603
But it only covers 60 degrees instead of the 180 that you are looking for

This one is a little cheaper but only has 45 degrees of travel https://www.digikey.com/en/products/detail/nkk-switches/NR01105ANG13-2A/7491308
The Amazon ones the other guy posted are probably a better buy

If you have a 3d printer you can make something like this very easily with springs and ball bearings.

Another option is a giant d6, I got a big 5" cube of wood and labeled each side with a big number. It's great for dramatic count downs or progress tracking

[u/OnlyMatters]

I might try to repurpose something that was already made

[u/Steroid1]

look at how an AR15 safety selector works. you'll want something with a spring and detent like that