My mechanical clocks

[2GodBDGlory]

There's some impressive engineering going on in there! It's quite interesting how those magnets improved the accuracy so much, and the compensation for thermal expansion is pretty next-level!

[Davidz90]

18 minutes ago, 2GodBDGlory said:

There's some impressive engineering going on in there! It's quite interesting how those magnets improved the accuracy so much, and the compensation for thermal expansion is pretty next-level!

Thank you very much! Indeed, the magnets provide a huge boost in accuracy - the fact that even doubling the driving weight changes the clock speed only by ~0.02% is kind of insane. I think that actually the most difficult part was having enough patience - a good 3 days of correcting the period by few microseconds, then waiting half an hour for the pendulum to reach a steady state to evaluate the speed...  

Edited April 29, 2024 by Davidz90

[Davidz90]

Final result after one month of testing. Max error: -6/+7 seconds.

And here is my newest build - a hollow clock face. Inspired by some 3D-printed clocks out there. Minute hand is fixed to one ring gear, hours hand is suspended by magnets on second ring. Now I'm thinking on how to power it. First idea was to use standard quartz mechanism out of regular wall clock, but these tend to have very little torque, just enough to move lightweight hands.

 

[Davidz90]

My newest creation, takes some solutions from the last high-precision clock (like the temperature-compensated pendulum), but uses a completely different escapement design.

 

[Davidz90]

Some photos and additional description:

The general structure of the clock is two towers with pendulum hanging in between. This arrangement makes it relatively stable and saves a lot of material when compared to traditional grandfather clock that encloses the pendulum in a case.

side

The tower is 170 cm high, but pretty narrow. In fact, total cost of this clock is less than twice the price of the recent Notre Dame cathedral set.

front

The clock face is a plate sandwich, put under very slight tension.

face

Finally, the mechanism. For power, I'm using a non-Lego DC motor plugged to a phone charger. A potentiometer (blue) is used to regulate the motor torque. Motor output speed is regulated by a fan.

mechanism

[Davidz90]

I got featured on Beyond the Brick channel :)

 

 

[Divitis]

These models look incredible.

Unfortunately I don't think I know enough about the inner working of a clock to appreciate your engineering.

If were to create a Lego clock engineering for dummies sort of video, I would be certain to watch it, and possibly would help me appreciate your creations more, if not inspire me to try my hand

[Davidz90]

24 minutes ago, Divitis said:

If were to create a Lego clock engineering for dummies sort of video, I would be certain to watch it, and possibly would help me appreciate your creations more, if not inspire me to try my hand

That's a cool idea! You are right, inner workings of a pendulum clock are surprisingly intricate and the physics behind them is truly fascinating. 

I have some plans to create a small, easy to build wall clock, with full instructions and detailed explanation of how it works.

[Davidz90]

Here's a small but fully functional clock, with full build instructions. It is designed to be clamped to an edge of a table/shelf or hanged on a wall. Driving weight lowers by 20 cm per hour, so at typical shelf height of ~160 cm, one gets 8 hours of working time.

link to the instructions:

https://drive.google.com/file/d/1tbNfih7dY28Cv3CotBCrR4Pl8SmZic_Y/view?usp=sharing

 

[Bluehose]

Thank you for that ! It's small enough to have a nice housing with few pieces, this is symetrical ans doesn't look expensive !

[Davidz90]

6 minutes ago, Bluehose said:

Thank you for that ! It's small enough to have a nice housing with few pieces, this is symetrical ans doesn't look expensive !

Thanks! Yes, compactness and low cost were my design goals here. Considered making it studless, but old school technic bricks are way more rigid with less pieces.

[Davidz90]

Next creation. For this one, I combined Lego with a little woodworking to make something in a more modern style.

1

It uses the same mechanism as my recent mini-clock. Due to longer, heavier pendulum, it is more accurate - up to 30 seconds/day.

2

The whole thing is fixed to a wooden board by simply driving screws through Technic holes and into the wood.

3

 

Link to a video:

 

[Davidz90]

For anyone interested, here's a link to instructions:

https://drive.google.com/file/d/1F0I6FHT8jyRJfaDp8Td_nGbjcEde0Jnu/view?usp=sharing

Given the amount of requests for instructions, tutorials and explanations, I'm considering writing some sort of a book on the subject of Lego clocks. There's too much stuff to cram it into a series of videos. It would cover not only the engineering topics and various Lego escapement designs, but also the physics of pendulum clock. However, I'm not sure if that wouldn't be too niche?

[howitzer]

48 minutes ago, Davidz90 said:

For anyone interested, here's a link to instructions:

https://drive.google.com/file/d/1F0I6FHT8jyRJfaDp8Td_nGbjcEde0Jnu/view?usp=sharing

Given the amount of requests for instructions, tutorials and explanations, I'm considering writing some sort of a book on the subject of Lego clocks. There's too much stuff to cram it into a series of videos. It would cover not only the engineering topics and various Lego escapement designs, but also the physics of pendulum clock. However, I'm not sure if that wouldn't be too niche?

That's definitely a niche, so I don't expect there's much money to be made at that. I personally would certainly be interested in reading a bit about Lego clocks but not sure if I'd be interested enough to buy a book about them...

[Davidz90]

3 minutes ago, howitzer said:

not sure if I'd be interested enough to buy a book about them...

Oh, I don't intend on selling it. It will be free.

[howitzer]

6 minutes ago, Davidz90 said:

Oh, I don't intend on selling it. It will be free.

In that case, if you think you can spare the time and effort, I would highly recommend and appreciate it.

[Davidz90]

So, I started writing the book. Part of it is discussion of various escapement types and small, easy to build examples of them. Here's showcase of the first four, each of them under 50 pieces:

 

[lcvisser]

This is very cool! I love the slow motion shots, it makes it so clear how they work. Following with interest!

[Davidz90]

Second part of small escapement demonstrations:

 

[Davidz90]

A new, large project in progress. A clock tower that will have 4 faces with various functions. Right now, regular time and striking mechanism are finished. I managed to make pipe chime with pretty good sound.

The idea to encode 1,2..12 strikes in a chain is not new, my improvement is a triggering mechanism that needs a very little force and is not grabbing the chain directly to stop. More details here:

Finally, the chime is one of the set of four, which will be used for Westminster chimes (the same melody that Big Ben makes)

 

Edited October 28, 2024 by Davidz90

[Davidz90]

My new, large project is complete! Clock tower with 3 faces featuring striking mechanism, world time, moon phase indicator and calendar.

 

[lcvisser]

Very impressive, as usual! Do you keep all your blocks assembled or are they reused? I see at least one big one in the background.

[Davidz90]

1 hour ago, lcvisser said:

Do you keep all your blocks assembled or are they reused?

They are reused. I have 4 clocks in total: the ones in the photo, one red (the one with 19 functions) and one black (accuracy world record). Red one will probably get a rebuild next :)

[LegoTT]

I will order these bricks and offer them with your pdf in a nice box to my nephew for Christmas.

[Davidz90]

5 hours ago, LegoTT said:

I will order these bricks and offer them with your pdf in a nice box to my nephew for Christmas.

Awesome! Which one, exactly? The black and white one has been built recently by one person, with transparent backing instead of wood, and it looks better than mine .