Satisfying Mechanical Calendar

If you're always losing track of the date, this model is the perfect 3D print for you. Wake up every morning to the satisfying press of a button that sets the gears turning and advances the date. 

Introducing.... 

The Satisfying ASMR Mechanical Calendar!

Usage Instructions

Simply press the button and the date wheel will automatically advance to the next date. If the next date is the 1st of the month, the calendar will automatically advance to the next month! 

(Note that this is just a simulation, the dates will be orientated correctly during physical assembly and the month wheel will only between the end and start of a month.)

In case you accidentally advance the the calendar too far into the future, simply lift up the lever at the back, press the flexible rack at the back of the button, and rotate the wheel back carefully. 

Assembly Instructions

Assembly of the calendar is pretty simple if you follow these instructions: 

1. Start off with the flat plate with some extrusions, and insert the tall rectangular tube housing into the tallest pair of extrusions in the orientation shown below. 

1. Take the spring and put it into the housing as shown below. Make sure to get the orientation correct or it may compromise the feel of the button or the durability of the spring.

1. Add the button now on top of the spring with the rack facing the open side of the housing as shown below. 

   

2. Now press fit or thread the axle with gears on either end into the left slot of the housing.  

   

3. Insert the end cap of this axle to the ratchet style gear, threading it through the corresponding slot on the housing. 

   

4. Next, use the little T shaped part and slide it into the slot created by the plate insert into the housing. 

   

5. For the pawl, gently press the sides of the housing outwards and then carefully insert the pawl into the circular dents. 

   

6. Press the big axle looking structure into the proper extrusions on the bottom plate. You may have to adjust the axle and its end cap to properly insert the structure without getting blocked by the axle.

1. With the axle in place, hold the spur gear into the slot and then press fit the axle into the hole. 

1. Next, add the big wheel with the months one face of it, putting the geared side onto the axle, so that the big gear meshes with the smaller spur gear you put in the step before.  

   

2. Next, press the bigger wheel onto the axle. This will require some force as there is a slight indent to lock the wheel into a channel to prevent it from slipping out and off the axle. 

   

3. Then, find the hole in the big wheel and press the cylindrical pin into it. 

   

4. Now for the best part, take the 31 date tiles and place them onto the corresponding pins. Starting from 1 at the triangular arrow and working clockwise as shown in the picture below. This time consuming assembly is designed that way because all the dates will be in a proper orientation all the time. 

   

5. Finally, fit the front case into the proper holes/channels and there you have it! Your button activated mechanical calendar is ready to get calendar-ing! 

   

How it works

This calendar works in three main segments. First we have to get the up and down motion into a one way motion of the bevel gear. To solve this problem, I use a ratchet and pawl system combined with a flexible rack. On the depress, the ratchet will happily rotate clockwise, but on the release, the button will go up, but pawl will activate and stop the ratchet. Meanwhile the rack on the button is actually not backed by solid infield, and is instead flexible, meaning it can flex backwards without triggering the ratchet gear too much.

The next part is to use the bevel gear to turn the date wheel by a constant amount each time. Because the down press turns the axle exactly 1/4 of a rotation, we can use that to get a 8:62 ratio on the bevel gear/date gear. Meaning every press meshes 2 teeth. 

The last part is rather interesting: I needed a way to rotate the month gear once every time the date turns from 31 to 1. So I have a pin that turns a gear 1/6 of its rotation. Which then meshes with the month gear to get a nice 1/12 rotation every time a month passes!