Safe with combination lock

prusaprinters

When I saw the <a href="https://www.printables.com/model/259699-safe-box-3-digit-combination">Safe box from Hugo</a> this inspired me to do my own Safe (or Lock).This is not a remix. I modeled everything in CAD from the scratch. But i printed Hugo's version before and  had a look at it. I recognized parts which he designed very well but also parts where I felt I could make it better. This is why there are parts which look quite similar.It's a nice gadget not a perfect safe (it's from plastic…). Helps to understand those combination disc locks and can be a evil gift box…False GatesI added some false gates in my design so make sure that the lock can't be picked that easily. This way you can't tension the lever and turn the discs until you feel that they fall into the gate anymore. It would be a huge portion of luck to get all true gates (8 false gates per disc). At least with my skill level it's now impossible to pick this lock.Double BoltsI also added a second bolt at the bottom so make sure the door has less play  in locked position and can't be bypassed this easily. Spring loaded DiscsDisc 2 and 3 are now pushed on by a spring in the bottom. This is to make sure they have more friction and don't move by themself after they are set. I had this issue a few times with the other design. (In defense for Hugo: i probably also got the tolerances too loose during printing his design).Case & HingeI made the case printed from 1 part. It really annoyed me to print the walls separat and to glue them then together. I totally understand why Hugo designed it this way. The door hinge will hinder you during assembly otherwise. But since I wanted to have the 1 piece case I needed a different hinge solution. I came up  with a spring loaded hinge. For assembly you press in the hinge bolts and as soon as you let them go the come out again. For the spring you can use a simple ball pen spring. Once the door is mounted in the case you can't remove it anymore (depending on how good your tolerances are ;) )CombinationTo make more different combinations possible I added 6 possible pin positions per disc. This way everyone can decide himself which combination is used during assembly.Case TypesI started with on case size. But the 120mm Version takes quite some time to print. Therefore I also added a 90mm Version which will take less time but also has less space inside.But I also felt that the whole safe just feels to ligthweight and cheap. Therefore I made a version where the walls are hollow. You can fill them with sand, resin e.g. and then glue on the cover cap. This way you get a more solid and heavy Case. Assembly:I tried to have as less parts glued as possible. If glue is needed somewhere will definitely state it here. If you print the parts from ABS it migth also be a solution to glue the parts by using aceton. That makes it even look cleaner.<ol><li>Disc assembly.</li></ol><figure class="image"><img src="https://media.printables.com/media/prints/282821/rich_content/6bc62b27-61af-4825-80f0-338b48b69872/image.png#%7B%22uuid%22%3A%22e8c5ca87-44bb-433e-9b1a-2825185e22ba%22%2C%22w%22%3A1069%2C%22h%22%3A694%7D"></figure>The only glue you need to use here is to glue the pins onto the disc. Pin 1 and 3 are actually the same so the direction doesn't matter. You can choose in which of the 6 slots you want the pin. By this you will set up your combination.The Axis should not have play with the discs. They have to move on the axis but not without a bit of friction. The spacers will have play.2. Turnwheel mounting<figure class="image image_resized image-style-align-left" style="width:64.78%;"><img src="https://media.printables.com/media/prints/282821/rich_content/5b421e29-e34b-40dc-bfcd-aa3f810031dd/image.png#%7B%22uuid%22%3A%228f613f31-2b19-4d3c-8edc-a28018ec6cfc%22%2C%22w%22%3A579%2C%22h%22%3A534%7D"></figure>            You put disc 1 through the hole in the door and then glue disc 1 to the turnwheel. Make sure that the axis still can move freely.3.  Mounting the lever<figure class="image image_resized image-style-align-left" style="width:68.87%;"><img src="https://media.printables.com/media/prints/282821/rich_content/858b570f-cf47-406f-9814-2bc336d6fc78/image.png#%7B%22uuid%22%3A%22f96d70d4-7441-4413-a748-923a605923f5%22%2C%22w%22%3A629%2C%22h%22%3A672%7D"></figure>               Put the Lever axis first through the hole in the door . Then glue the knob onto it (Make sure to testfit the lever first so the knob is in the correct orientation.) The lever doesn't need glue. It will hold in place by the axis shape (thank's Hugo for this idea). Just push it onto the axis.4. Mounting the bolts<figure class="image"><img src="https://media.printables.com/media/prints/282821/rich_content/1f3f2ed7-96d8-4bf4-a8d8-5428dbf72b0c/image.png#%7B%22uuid%22%3A%22ce2e81bd-d4b2-44cc-b3cb-0111ca3c4518%22%2C%22w%22%3A910%2C%22h%22%3A603%7D"></figure>The main bolt is just layn over the lever. Then latch 1 and 2 are glued onto the door.The secondary bolt can be cliped on the lever (depending on the printing tolerances). Then latch 3 is glued to the door.5. Disc spring<figure class="image"><img src="https://media.printables.com/media/prints/282821/rich_content/6da3c014-066d-4c9f-826d-6a89e81597e2/image.png#%7B%22uuid%22%3A%22e0741141-4b25-4e51-8ac9-d9ddf97db1d1%22%2C%22w%22%3A1071%2C%22h%22%3A659%7D"></figure>The Disc springs job is too put friction onto disc 2 and 3. It probably requires some supports to print it. The spring just needs to be pushed into the door backer. Make sure it fits tight. There should be some strain on it.6. Door assembly<figure class="image"><img src="https://media.printables.com/media/prints/282821/rich_content/bb47a115-6b11-4a98-95cf-48747227b3aa/image.png#%7B%22uuid%22%3A%225722fbd9-7605-468a-85bc-4795551b1fa5%22%2C%22w%22%3A748%2C%22h%22%3A625%7D"></figure>The door backer (with the spring) can now be glued on the door. Make sure the lever axis can move freely. The disc axis shall not move. If you want to be sure you can also glue it to the door backer. But it should also stay in place without glue.<figure class="image image_resized image-style-align-left" style="width:92.38%;"><img src="https://media.printables.com/media/prints/282821/rich_content/60262adf-048f-41bb-bdf3-47e4d1b11ceb/image.png#%7B%22uuid%22%3A%223545be10-79a5-497b-a064-414ffaff3e0c%22%2C%22w%22%3A1139%2C%22h%22%3A596%7D"></figure>          The cover plate can now be glued to the Door. It is actually not needed. I just designed it to get the mechanism more closed and harder to bypass. It will also make the door more stiff.7. Hinges<figure class="image image-style-align-left image_resized" style="width:53.11%;"><img src="https://media.printables.com/media/prints/282821/rich_content/718c74ea-f7db-4201-8fee-7806c2781726/image.png#%7B%22uuid%22%3A%22a1e61441-39ef-4a44-923e-b5d586313e4d%22%2C%22w%22%3A510%2C%22h%22%3A602%7D"></figure>             The hinges have to be pushed into the hole in the door. Put a spring (normal ball pen spring should work) in between them. The spring should be strong enougth to push the hinges out. Stronger is better here. You can also add shims or something similar (i used a short bolt) to put on the spring and give it more pretension. The spring still has to allow the hinges to go in completely.8. Final assembly<figure class="image image_resized image-style-align-left" style="width:80.97%;"><img src="https://media.printables.com/media/prints/282821/rich_content/dfc9b732-b3dd-4141-bbcb-11543000fd5e/image.png#%7B%22uuid%22%3A%22272b1e85-30c8-4513-b9bf-83c6c8f5ef76%22%2C%22w%22%3A709%2C%22h%22%3A592%7D"></figure>              For the final step is to push in the hinge pins on the door, and push the door into the case. You can let the hinges go and move the door until the snap into place.Try  to put the door in place first without the hinges to see if the rest fits (if the bolts fit…).Make sure you know how the lock works and what your combination is before you lock the door… Lock mechanismTest unlocking the door first with the door open, so you can see the discs.<ol><li>Turn the Wheel 3 rotations left to make sure that you picked up all discs.</li><li>Turn the stack past 0 and then until the gate of disc 3 is in its correct position.</li><li>Turn now in the opposite direction (rigth) past 0 until you pick up disc 2 again. </li><li>Then turn disc 2 till the gate lines up with the lever.</li><li>now Turn again the opposite direction (left) past 0 until the gate 1 lines up with the lever.</li><li>Turn the lever until the bolts are in the final position</li></ol>

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