A 100% Lego watch equipped with the mysterious mechanism 'Mangle Rack Mechanism' is born
Lego is a toy that allows you to combine various types of blocks to make various things. So far, masters have created works that go beyond toys, such as
You can understand what kind of mechanism the 'mangle rack mechanism' is by watching the following commentary movie by Mr. Akiyuki.
Prepare a plate with an arc guide around it and a protrusion in the center that meshes with the gear.
Place the plate on the rails, engage the gears on the protrusions and rotate them to move the plate back and forth. This is the mangle rack mechanism.
The feature of the mangle rack mechanism is that the operation can be changed depending on the shape of the plate.
If you prepare a square plate as shown below and fix the position of the gear, you can move only the plate.
The plate moves irregularly without a guide, but you can move the plate regularly by mounting a fork or installing a pin as a guide as shown below.
The following movie created a clock using such a mangle rack mechanism.
As mentioned above, the mangle rack mechanism can move the plate regularly by preparing a guide. However, with the method of 'biting the pins between the forks', the number of pins will always be an odd number.
The number of pins is even because you need to move the second hand in 60 directions to make a clock. Therefore, we adopted a method of 'biting a fork (needle) between the pins' so that the plate can be moved regularly even if the number of pins is even.
This is the clock frame. There are 60 pins inside the donut-shaped frame.
The back side looks like this.
The central part of the mangle rack mechanism is below. The red stick acts as the second hand.
However, when I attached the above needle, it advanced by 3 scales.
The reason for skipping the scale is that the stroke of the needle is too long. Therefore, we changed the design of the central part of the mangle rack mechanism and reduced the stroke of the needle to one-third.
Now you can advance by one scale. In this state, if you rotate the motor at 247.5 rpm, it will advance by one scale every second.
Next, create the minute hand. First, attach 60 pins to the frame.
Next, prepare two sets of Lego '
This set includes a golden chain. At the time of making the watch, it is necessary to buy 'BMW M1000 RR' to get the golden chain.
Connect two sets of chains ...
Attach the red part that acts as the minute hand.
Attach a chain around the pin.
This completes the minute hand.
Next, create the following parts to move the minute hand.
Pushing this part from below advances the chain by one scale.
In other words, every time the second hand reaches the 12 o'clock position once every 60 seconds, the chain advances by one scale and ticks one minute. A mechanism unique to the mangle rack mechanism that moves the needle up and down.
Now that the second and minute hands are complete, it's time to create the hour hand. First, attach the red parts to the ring gear ...
Set the ring gear under the short hand.
Next, attach the gear that supports the ring gear ...
Also attach the dial.
Next, attach a gear train on the back that receives the power of the motor and moves the hour hand.
This watch requires a 1:11 gear to move the hour hand. However, it is said that Lego does not have gears with multiples of 11.
So I made a 1:11 gearbox using a differential gear .
The 1:11 gearbox is built into the yellow frame position.
After that, turn on the power and the clock will start running.
However, if it is driven by a battery, the power will be used up in a short time ...
I attached a clip so that power can be supplied externally.
The power switch is located on the bottom of the watch.
When you turn on the power, the clock will start moving.
You can see how the mangle rack clock created by Mr. Akiyuki actually works from 8 minutes 27 seconds of the movie . Also, at the end of the movie, the accuracy is checked side by side with a commercially available watch, so if you are wondering how good the performance is, please play it.
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in Video, Posted by log1o_hf