Soda bottle combination lock

prusaprinters

<p>This is a combination lock for soda bottles. For a long time a have been wanting to design an make a lock for soda bottles, and my inspiration for that - my family members often would drink my soda. I have no problem with sharing, but if someone dranks half of my soda and adds water to it so it doesn't look like they had emptied half of the bottle... the diluted "soda" of course wasn't drinkable, plain tap water tasted much better.</p><p>Once I designed it I realized that it could also be used as a child safety lock for those people who like to store liquids such as oil, petrol, solvents etc in soda or water bottles .</p><p>fusion 360 file included<br>STEP files included</p><p>this is a version 3 of the combination lock, ...so...what happened to version 1 and 2?<br>version 1 (initial prototype) - couldn't assemble due to improper tolerances.<br>version 2 (first functional prototype) - assembled with glue, so... once its glued the combination couldn't be changed<br>version 3 - slightly stronger geometry and instead of glue it uses 3x M3 bolts and nuts (10mm long bolts), the combination can be changed by changing the combination rings.</p><p>known issues with version 3:<br>very loose tolerances but on the other side - printable by not so tuned 3D printers.<br>quite easy to decode, but safe enough that a child couldn't open it.<br>bulky,<br>rings lack fixation - rotates too freely therefore can be challenging to align the rings to unlock. Any damage that affects the tolerances will inevitably result in having multiple working combinations.</p><p>version 4 - work in progress,&nbsp;</p><p>main objectives for future lock versions: make the lock smaller and make it a lot harder to decode, in other words, a complete redesign required.</p><p>for assembly 3x M3 10mm long bolts and 3x M3 nuts required</p><p>&nbsp;</p><p>by personal experience with this model, it is recommended to be printed with PETG filament for durability, it should handle a drop from 1.5m height with a full 2l bottle against concrete (Note: results may wary) PLA might be too brittle if dropped, DO <strong>NOT</strong> EVEN THINK ABOUT PRINTING THIS WITH <strong>ABS, ASA</strong> OR SIMILAR MATERIALS THAT EVEN DO NOT EVEN HAVE A CHANCE TO QUALIFY AS FOOD SAFE &nbsp;</p><p>&nbsp;</p><p>about printing the model:</p><p>print all of the parts except: all “combination rings” ,"base ring" and the “bottle”</p><p>you only need to print 4 “combination rings” of the 10 available ones,&nbsp;</p><p>chose a random 4 number combination, then print the “combination rings” with each of 4 numbers.</p><p>recommended print settings: infill min 50% and slightly higher print temperature than usual, for increased strength&nbsp;</p><p>&nbsp;</p>