Gears! Design Contest

THIS CONTEST IS CLOSED  –-  THE WINNERS(!):

Mcchat's Model automatic transmission

henryseg's Gripping gears

Thorin Oakenshield's Mechanical carousel with horses

Thank you everyone for participating in my experimental contest! All the entries were extremely high quality (and interesting), and I especially appreciate those of you who designed something specifically for this contest. If you have any questions about my judging rational, please post comments and I will try to answer. I believe this is the sort of transparency people would like more of from the official Printables contests.

Prizes: I will be messaging the winners with a request for whether you'd like a voucher for PLA or for PETG (the only filaments currently offered with the Prusameter rewards). Once you respond, I'll send you a voucher code you can use in the Prusa store. It can take Prusa a few days to issue me the voucher codes, so please be patient.

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THE CONTEST

What's this? An unofficial design contest? Yes! Enter your gear-oriented design for the chance to win a free roll of filament.

CONTEST THEME (Contest end date: February 15, 2024)
This inaugural contest of mine is all about gears: spur gears, bevel gears, worm gears, cross helical gears, or any other type you can think of. Some sort of gearing should play a dominant role in your design. Could be a gearhead. Or a geared phone stand. Anything with gears as a central component. The rubber band shooter model posted here, with details below, is my example of a gear-themed model. (Feel free to download and print it, and no, I'm not entering my own contest.)

PRIZES
Vouchers for a free roll of filament (Prusament PLA or PETG) will go to the top 3 entries. I've got a bunch of unused Prusameters which I will redeem for a filament voucher of the winners' choice (PLA or PETG), and then I'll DM the winner with the voucher code that they can use in the Prusa store. (Note: the vouchers don't cover shipping charges.)

HOW TO ENTER
Just post a comment here on this model with a link to your contest entry model on Printables. Also add a photo of your model to help me recognize it.
(Note: Other comments are welcome as well - good to keep things lively!)

ELIGABILITY
Any design, posted at any time before the contest end date (February 15, 2024), is eligible,  provided that:

1. It is primarily your design
2. It adheres to the design theme
3. There is only one entry per Printables User

Note that if you want to change your one entry, simply delete your comment/entry and add a different one. I'll be calling out in the comments any design that I don't think fits these rules. Also I've never done this before, so I may add rules on the fly as needed. (This contest is only for Printables users and entries must be posted on Printables.)

JUDGING
I'll be the sole judge of what I think are the best entries. I may not be rational. What I'm really looking for are clever, well designed models that may have been overlooked by the community in the avalanche of daily model postings. In fact, as entries are posted in the comments, I may add a reply noting the number of likes and downloads at the time it's entered (or, you could do this yourself). Perversely, the fewer likes the better!

WHY AM I DOING THIS?
Initially, I thought of sponsoring my own design contest as a way to put my unused Prusameters to work. But my other motivation is to help curate worthy designs that have otherwise gotten buried in the firehose of daily design postings. (We've all posted great designs that have gotten absolutely no traction.) That's why I'm accepting both old and new designs.

I'm also doing this to keep myself entertained. If this ceases to be entertaining (too many junk posts, too many mean comments, too much whining), then I'll simply take this down and pretend it never happened. Hopefully we won't have to go there.  I'll be looking forward to your entries, and good luck!

(Note: I've checked with Prusa and they seem OK with me running a design contest on the side, but they are otherwise not in any way involved with this contest.)

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And now, about the example design I have posted: a new 21-Shot Rubber Band Gun

Note: The printed version shown was on my Bambu P1P, and it turned out just slightly too large for the Prusa MK3/4 printer bed. I've scaled down the files to 98% so they just fit the Prusa printers. Please let me know if there are any issues.

With this 21 shot rubber band shooter, you'll be able to rain hellfire (hell rubber?) down on your competition. This is a completely redesigned version of my earlier rubber band shooter with a vastly simpler trigger and indexing mechanism, and more stretch for longer shots.

The mechanism uses a pawl and ratchet for turning a worm gear that both advances the magazine and releases each band. Pulling the trigger causes the worm ¼ turn, advancing the magazine by one tooth. The leading edge of each of the 4 threads on the worm is what pushes each rubber band off of the nub above each tooth gap.

Printing
Print one of each part, except for two of the screws. I used PLA with 0.2mm layers, 3 perimeters and 15% infill. No supports are needed.

Assembly

1.  
   Remove the small built-in support that sits in the trigger slot.
    
2.  
   Insert the trigger into the slot
    
3.   
   Slide the U-shaped clip over into the notches in the trigger to hold it in place.
    
4. 
   Slide the pawl into the slot at the back of the shooter and place the hole in the end of the pawl onto the post on the trigger.
    
5.  
   Screw the worm onto the back end of the shooter with one of the screws.
    
6.  
   Hook a small rubber band between the hook on the trigger and the hook on the frame.
    
7.  Screw the tip of the magazine into the front end of the shooter with the second screw.
    

Play
You are now ready to load the rubber bands. The stretched length of the bands is about 280 mm and you can use any 1.5-3mm wide bands that will stretch that far.


Now pivot the magazine around so that the left-most tooth engages the worm. Each pull of the trigger should advance the magazine one tooth and release one rubber band.