Going towards the end of the project, we needed to assemble and finish up the locker. This includes both the electrical circuit and the case.
Last week we laser-cut all the parts to the locker-case and cut metalpieces for the lock. We started making the case, gluing the bottom and two sides together. This made it a lot easier to work with the things we were missing, because we easily could measure and test things on the locker.
Since last week the handle was changed. Instead of the handle showed in last weeks post, we made a leather loop, which we all agreed was a great look to the locker. Further it only had to be fastened with one screw which made is easier and cheaper:
The next thing we looked at (while some struggled with the coding part) was how to hang up the locker on the walls in Skylab.
We discussed many ideas, almost all included a two piece system. An example is a shelf-system, the prototype (for the wall piece) can be seen below:
For simplicity we would rather avoid having a second piece for our locker, and decided to try making a solution with hooks put directly on the locker, that could go in the wall-holes and be stable enough to hold our locker straight. Putting an angle on the hooks would make this possible, drawing below:
To make this solution we found a long piece of round metal with external treads. This was flexible enough to be bend (with a radius) but still strong enough to hold the locker. The threads is a nice plus, since it makes it harder to push out the locker by accident (because of the resistance from the thread). First we cut two pieces (aprox 5 cm), and bend them using the bending tool. The angle was made by eye. The two hooks was mounted by welding them at a strap of metal which could be screwed into the locker.
To avoid the locker incline towards the wall, we put a bolt in the bottom, so that the locker will be straight while hanging.
Next we needed to make sure it was easy to close the locker properly before locking it. Here magnets was the obvious choice. We glued to pairs of magnets on the locker connecting the door and frame. One at the top and one at the bottom:
After this, we started thinking about the mounting of the different components (RFID, OLED, Breadboard, Button, lock). We quickly agreed that we wanted the OLED and RFID mounted in a way so we could easily put it on and off, since this would make replacement of components easier. As the two components both has holes that could be used for mounting, we decided to use tread and bolts. First we measured and noted where the metal pins had to be placed to fit with the components. Hereafter we drilled small “pockets” for the metal threads, we were able to glue them on. Some of the assembly is seen below:
The Button was glued to a wooden brick that was screwed to a groove in the top. To make sure it sat in the correct position (registering when the door locked), we made a fine adjustment trying different position moving it a couple of millimeters, tightening it, trying it, and then move it again till it was on the perfect spot.
The servomotor (with applied beam for the lock) was placed between to sheets of wood, hold together with screws and bolts. This wood was glued to the side of the locker, carefully measured so it could fit (both when locked and unlocked). The two metal pieces, catching the beam was glued, one on the stationary part of the front and one on the door, to make the most robust solution (making the moment in the beam as small as possible).
The breadboard was glued to the side of the locker, and finally a hole in the back was drilled to make space for the power-supply to run through.
Now we were ready to connect the whole thing and try it out in the final version for the first time!
Obs.: On the image the lock is not attached yet.
When trying the system a strange observation was made. The function making the button regestrate whether the door is open or closed only functioned from time to time. At first we thought it was a loose connection, but after investigating the error, it turned out, that the button only worked when the serial monitor was open. As soon as we closed the monitor, the button didn’t work, and we could lock the locker even though the door was open… We found this very strange, and read the code many times to look for mistakes, and welded the connection to make sure it wasn’t loose. The only thing left was to look at the pins, and it turned out the problem could be solved switching the button pin to another one in the bread board (pin x to pin y).
Now the whole system was up and running. All the things were assembled. To protect the wires and circuit, we used tape so it didn’t hang from the top. We also cut out a box to frame in the main part of the circuit. The box was lasercut in 3 mm clear plexi. It was made so needed wires to the: Lock, Power-supply and button could be connected to the components outside the box:
The plexibox was glued to the side of the locker.
We did a lot of test with all possible userstories, to make sure all functions worked – it did!!!
After the box was safely mounted, we could close the locker, gluing the last side to the structure. We decided not to glue on the top of the box – why?
Because of the loose connection of the power-supply wire. If the locker is locked and the wire falls out cutting the power-supply, we wouldn’t be able to open the locker and put the wire back in.
Now the locker is done!