Mini D-Ring Binder Mechanism Organizer Concept

I'm hoping this is a first 🤞; the first FDM 3D-printed binder mechanism? Not really meant for actual use; it just needs to be the first 😅. Although not 100% 3D-printed, the spring, bistable mechanism, and rings are, so I'm still counting it! Been playing around with bistable C-shaped leaf springs (see Glasses Case and Tackle Box), and a binder spring is pretty much the same thing, except the C-spring is extruded to be really long and has holes that allow rings fastened inside to pass through. It's a very non-standard ring profile (so screws can fasten), so I modified tackle box trays from the Tackle Book as pages for an example of interesting "stationery" - along with modifying the case for the binder covers. Demo and assembly at https://youtu.be/1c2v9sq0Abk

Caveats This is a proof-of-concept project. It has several issues that prevent it from being practical: - Not as strong as a traditional steel spring

- Rings are too flexible

- Plastic fatigue

- Non-circular ring profile and teeth shape can snag pages being moved across.

- etc.

Tools and Extra Hardware - Snips and Pliers

- Plastic-compatible threadlocker - Optional

- DO NOT USE NORMAL LOCTITE; make sure it's plastic-compatible (I just used Elmer's Glue).

- Countersunk M3x8 Screws - x6

- M3 Nuts - x6

- Countersunk M3x20 Screws - x6

- M3 Nylon Locknuts - x2

- Can be replaced with normal M3 nuts and threadlocker if desired.

- Screwdriver for screws

Printing All parts should already be oriented correctly, with the correct side lying on the bed. The spring should be PETG, but it probably doesn't hurt to make the entire mechanism out of PETG. - Spring.stl - x1

- PETG

- Needs overhang supports for ring holes. I would also recommend tree supports on the left and right sides for the bottom 1/2 of the height for shoring.

- Recommend printing with a brim.

- At least 2 perimeter layers.

- HingePlate.stl - x2

- Ring_A.stl - x3

- Ring_B.stl - x3

- Cover_Top.stl - x1

- Supports needed below hinge pins.

- Cover_Bottom.stl - x1

- Supports needed below hinge pins.

- Cover_Back.stl - x1

And page contents This D-Ring binder isn't shaped like a normal one. A normal D-Ring binder is considerably taller than the expected paper stack it can support (at least without curling the pages), so the rings don't collide with the cover when it's empty. I didn't want that extra wasted space, so it's more compact, but that also means it only works well when it's filled with just enough so that both the top and bottom covers are parallel. - Page_Med.stl - x3

- Tacklebook_Long_Lid.stl - x30 (3 per page)