I don't get it. How does it work?


The top side of the nut has a fillet on the edges. The bottom side of the nut does not. The spring pushes all the nuts against the small lip you can see. Upside-down nuts will slide over this lip due to the fillet, correctly oriented nuts will not.






> fillet on the edges Since it's on the outside isn't it a chamfer then?


I believe a chamfer is usually flat and a fillet is usually rounded, regardless of inside and outside corners.


After looking more into it I think you're correct.


chamfer is flat, bevel is round, fillet is in the inside, atleast what we use in 3d modelling


I'll have a chamfer mignon au vin.


It's technically a round. I was taught in drafting class it's a fillet if you have to "fill it" (aka add material) to create it, and a round otherwise. A chamfer is an angled flat. [https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2019/ENU/AutoCAD-Core/files/GUID-357499AE-7EF5-4228-8DE9-7FA6A8F11C27-htm.html](https://knowledge.autodesk.com/support/autocad/learn-explore/caas/CloudHelp/cloudhelp/2019/ENU/AutoCAD-Core/files/GUID-357499AE-7EF5-4228-8DE9-7FA6A8F11C27-htm.html#:~:text=A)


Ah that makes sense. I did see some sources mentioning the metal stress is the reason for having a round vs a fillet.


My best guess- The “top” of the nut has slightly rounded edges but the “bottom” doesn’t, so they sit flush on the surface of the channelif they’re the right way up. If they’re the wrong way up then the curved edges are down. Think of it like a bowl - the “top” curved side of the nut is the bottom of the bowl, and the “bottom” square edge of the nut is like the top of the bowl. The channel they’re all being pushed down has a side to it, but there’s a small section (opposite the spring) where the side has been cut down to just a fraction of a mm tall. So when the nuts come down the channel like they should, like upside-down bowls, they get to the spring which pushes them against the edge and their flush bottoms catch on the wee lip that’s left and they keep moving down the channel. However, when they come down the channel *wrong* way up (AKA like a bowl that is ready to be filled with soup) then the curved bottom means that the pressure from the spring pushes it up and over the small lip therefore removing it from the channel!


Thanks. I was thinking this had to do with the thread and could not find an answer.


~~One word: friction.~~ ~~To the downvoters - it _is_ friction. I'm guessing your disagreement is that it's the lower side of the bolt is elevated and that's what makes it easier to be flicked off of the small railing? Well, having an elevated lower side makes it have less surface area touching the ground - which is what reduces the friction. The going-over-the-railing part is just to keep them snapped into two distinct pathways. It would probably still work without the railing, but might have a few more false positive. My point is that the bulk of the work (I'd guess ~90%) is accomplished by friction.~~ ~~You can see how the right-side bolts barely move whereas the upside-down bolts are flicked off with a substantial force. How else would you explain this huge difference in force applied by the same trigger? Friction!~~ ~~Otherwise you might as well take into account the railing on the far side that actually stops the flicked off nuts...~~ Edit2: Actually yeah, nevermind. I concede after seeing the diagram above.


Mechanism that selects only deez nuts


How that works is nuts. I’ll see myself out.


Don’t bolt out the door, no need to rush.


Screw off and get out!


Buddy's torqued


Screw it https://youtu.be/dQw4w9WgXcQ


Why do the nuts have to be "right side up" in the first place?


They’re either being packaged in a certain way or are being pushed along to another automated process which requires them to be right side up. Kind of like a harmonic beater bowl in an automated assembly process.


To satisfy QC. The markings must be visible to verify the type and grade of fastener for inspection. Also, you'd want the smooth side against the workpiece anyway; there's more surface area for contact and force dispersion.


one side is flat to provide a larger contact area against the fastener, the other is rounded i think just to reduce sharp edges. i don't think there's any other mechanical reason for the rounded side


Wonder how long it will work until that lip wears down.


I would imagine 30 years ago this process required hiring 2 workers until someone found out they could just use a tiny spring.


or the spring loses its springiness


it going to get caught and f’d up well before losing springiness, and they’ll just replace it as needed. it’s a cheap little spring.


yeah but I still wanna know how long it lasts lol


I'm curious as well and how long this would hold up overtime


Since it's two pieces of steel with very little pressure applied? A million years, maybe?


duck, duck, duck






So somebody’s job title is upside down nut flipper? I kid. I suppose once a certain Count of upside down nuts has been collected there is a mechanism for turning them all right side up at once.


Anyone know what’s written in red just above the spring?


Does the other row in the left have another mechanism? It looks like it mostly holds upside-down nuts but there's a few right-side-up nuts in there too.




Pretty obvious how it works


Freakin hate it when my nuts are upside down, so this makes total sense.