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3D printed combination lock anyone? Answered

I am in the finnishing stages for a fully 3D printed dial combination lock, similar to what would be used on a safe.
Unlike what you might find in other places there is no metal parts.
No crappy amount of possible combinations either, 72 per dial dial...

I took me a few weeks and quite some filament to get from a draft in Sketchup to something that actually works as planned.
As it was more a training excersize in Sketchup for me I had the the following goals:
1. Everything is 3D printed with as little afterwork as possible.
2. All required springs are 3D printed as well as all other moving or stationary parts.
3. Where otherwise fasteners or screws would be required only short leftovers of filament are used to keep the parts in place.
Only exception for security reason is the mounts for the front dial and holder.
These should be glued or screwed in place if the actual intention is to use it as a working lock.
4. The lock shall not be pickable by means of felling, hearing or just trying out random combinations.

The above points I got sorted to my satisfaction.
However I would like some feedback from trustworth beta testers on the general design and functionality.
It is one thing to design something that just works but a bit harder to design it the best possible way.
Another big drawback currently is that it seems to be impossible to export proper STL files in Sketchup once they reach a certain complexity.
Automatic services or programs to fix these issues result in drastically increased file sizes.
Some of the problematic part go from just under 200kb to over 10mb after "fixed".
This is not acceptable for me and I have to work on fixing this issue.
Most slicers correct these tiny errors automatically and produce a correct print but I prefer proper STL files of small size and complexity over inflated ones that I then need to double check for a long anyways.
A few details need changing as my tests showed that you can't drive up print details to a certain level without risking to be unable to mount the parts without further sanding.

I hope to have a full set of clean STL files ready for testing by the end of this month.
If you are interested to try it out and maybe contribute to an improved version your time will be valued by being mentioned as a beta tester for the upcoming Instructable.
Be warned though!
This is not for the faint of heart and certainly not for someone who does not know how to calibrate all aspects of the 3D printer involved.
The lock also uses quite a bit of filament, currently around 37m all up but I am working on reducing this by replacing solid parts with framework instead where possible.
The assembly can be time consuming and frustrating if you realise only once finnished that you have certain parts in the wrong position or orientation.
But as said, my goals were not really on making it as easy as possible LOL
Why desing a lock that is neither secure enough nor free of metal parts if there is other options ;)

If you happen to work with an Inventor and PLA on the left side then I can provide ready to go .gx files if prefered.
They would then be already confirmed to be working and usable on one of my printers.
Let me know what you think ...


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