Open source deadbolt lock

Hi, guys! When I started to read this topic I expected to find some solution at the end of 200 posts. But looks like have no any solution here was found for this pass six months, so I decided to build lock by myself. Now it already works, but I’m waiting for MOSFETs and Boost converter for effective powersave mode.This lock will be (probably) based at ESP32, RC522 as RFID reader, DRV8833 as motor driver and 3xAA battery as power source. :slightly_smiling_face:

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You weren’t kidding!

… more importantly than that… tell me about your mechanicals… it looks as if you gutted one kind of electronic lock and you’re changing out the electronics for your own stuff. Is that the case?

I’m living in China now and we have here a lot of diffrent electronic locks, but unfortunately I always have some “special requirements” :smirk:
All of locks which I tried has no support for my NTAG216, only M1 keys. I decided to replace PCB in existing lock, but for security reasons (I do not trust to untested DIY PCB :grimacing:) I want to have lock with possibility to open by key from inside and outside.
I checked a hundreds offers of diffrent locks and spare parts at Taobao.com and didn’t found anyone which I want to reassembly. So finally I coose this one (part?), which is same like my currently installed.
This lock is very similar to usual hotel locks, it have free moving doorhandle while lock in “closed” state. Internal motor can lock/unlock handle even from one AA battery (as I found). As bonus this lock have six microswitches, which can be used for lock state processing. ¥125 = $17.6

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@amal Did you end up having any luck sourcing those parts?
(Light pipe & motor)

no… right now we are just interested in getting our hands on a stamp or even a print of the mounting plates so we can verify pcb and motor mounting and DFM … i keep having short conversations with lock companies who basically want to work with us but not produce our stuff, they just want us to buy their lock with some firmware mods… but in all those cases, the locks are not ideally designed and they cannot or will not offer a lifespan commitment… so i’m back to wanting to produce our own stuff from scratch.

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Ok no probs, I will manufacture a few prototypes of the mounting plates from steel when I can then.
I was ideally waiting for the motor to get the mounting right first time but this is workable too.

Edit: will send one to you if that’s ok?

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@amal I can 3d print one of each out of PLA right now and send it if that helps at all?

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I will happily accept PLA prints if they minimize shrinkage, but yes metal plates are ideal… but before shipping things let me look into the motor we sourced first and get at least one of those into your hands so you can check mounting.

I printed the external plate from PLA last night and here are the results.

Unfortunately because it is PLA it broke pretty easily at the point that the rods attach, but before that it fit pretty well.

I will make one out of metal ASAP and then send some more pics.

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Yesterday received 3D printed patrs and install first version of my lock. Already found some problems, modify drawing and reorder 3D printed parts. Now looks not very good but it already works :sweat_smile: Power consumption near 19uA in deep sleep mode (using internal ESP32 touch pins) or near 11uA with external capacitive touch button (blue pcb inside of green antennas pcb).

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Just thought I’d update on the one I’m building.
I 3D printed some parts of it in PET-G with some design modifications to allow easier manufacturing from metal.


Sorry this is taking so long, I am very busy with work and moving home at the moment, but I do intend to complete this project.

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Thanks @conphilpott! Those look great.

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I just wanted to thank all you makers, designers and electronics tinkerers :pray: that are working on this project. Thank you for keeping it going and actively working on this, I really do appreciate all the time and effort you’re putting in. :heart:

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Just a further update, I’ve started making the bits from metal. Here are some photos.

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This looks really great
If it can be of any help I have access to a 3 axis cnc machine and 5 axis one and I have good contacts with someone with a laser cutter maybe I can help with something?

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Thanks, I will hopefully be finishing both them plates on Monday.
Then the next part is the external plate which will be a milling operation with turning to finish it, I also have access to a CNC 3 axis lathe and a CNC mill along with their manual counterparts.
There are still some changes to make to some of the other parts so I won’t post them just yet, unless you would like to look over them?

I have spoken to the owner of the machines and they are prepared to do a full production run once the prototype has been approved and an order is placed.

TBH the things that I am struggling to work out how I will make are the plastic casings and thumbturn (maybe machined ALU?). Ideally they will be injection moulded but I suppose 3D printing in pet-g as it stands up to UV light well is also a viable option?

Also the PCB and software are a hurdle to overcome, like what sort of size they need to be and how thick the one in the external part will be with the antenna.

I don’t suppose anyone has any ideas what chip to use? I have a couple of PICs including a 100 pin one laying about or I suppose an ATmel chip could work? Just trying to think of the crypto functions for Desfire and the ability for them to be integrated into the VivoKey system by @amal

tldr: Progress being made, hopefully finishing plates on Monday and starting the other parts then too.

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ah okey sounds good :slight_smile:
i have a manual lathe and a mill and also a small 3 axis cnc in my home workshop so maybe i can make a prototype for you before you go to the more expansive machines

i can look over them more eyes can maybe spot a problem right ? i can maybe give some at advice machinabilaty of the parts my day job is programming cnc machines and operating them

on the thumbturn i would go for alu because its more durable but on the other side it is also more expansive or i could make the mould for injection molding but that is something i have never done before i did make moulds before but then for castings and vacuum forming

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Here is my github repo GitHub - ThermalAxis/lock-deadbolt: Open source deadbolt lock design
I have just pushed the latest version of everything I have, there are some version mismatches and incomplete drawings but most stuff is there.
All the 3D stuff is up to date.

Ideally the part called external plate rev1.5 is the next to be made and it lines up with some of the holes on internal plate and the deadbolt itself.

Moulds would be great!
Again though some improvements needed before that like fasteners for the PCB etc. Not trying to hold anything back, I just don’t want you to waste your time and materials before it is ready for a proper prototype.

Yeah I was thinking the same thing about the thumbturn, ALU would feel nicer in the hand but it adds cost. I’m currently printing one so will see how it fares soon.

Any chance of getting one of those motors please? I have a feeling we aren’t far off now.

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Once we figure out the dimensions of the lock body, I’ll be able to design the PCB and antenna. I mentioned this earlier in the thread, but I plan to use a PN7462 from NXP as the microcontroller. It can handle the antenna communication directly and has built in support for cryptography and communication with secure elements.

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Ok, cheers.
Sorry must have forgotten about that.
I’ll draw up a size constraints diagram tomorrow morning.

Just curious, do you have a datasheet for that chip?