Unconventional ways to display numbers , analog clocks ? - Page 1
Forum section: electronics / projects

author: osmax_br
author_rank: Regular Contributor
timestamp: March 29, 2025, 10:07:23 pm
content: Hello everyoneI have this weird hobby of displaying numbers in weird/unconventional ways , I don't want to just to display them on a 7seg or an LCD it is not unconventionalI was thinking today of using an analog clock to display numbers like temperature or yt subscribers (or time of you want) , etc....I am thinking of something like the old planes gaugesI know that there is a way to implement that using a servo and a 3d printed arrow and a piece of cardboard to write down the dashboard numbers , but this isn't fun and isn't as weird as a clock , also I have many analog clocks that are laying down unused and I want to do something with themI am thinking of 2 ways to do this :1- we have the rotating knob that sets the time , I could in theory attach a small stepper motor to the gear , by moving the stepper the time (numbers here) changeEg: hours hand is on 12 , I want to display 6 , I move the stepper until the hours hand on "6"2- what I meant by analog clocks not these very old early 1900s ones that is spring powered, nor the purely mechanical ones , I am talking about modern cheap Chinese analog clocks , which has a small circuit with a crystal that generates the pulse required to move the clock by one second (there is a small motor inside) , I am thinking of changing the frequency of the crystal (remove the crystal and connect an mcu/ic to generate different pwm signals) , by that I could speed up the process to reach the desired number and don't need to connect addition stepper motorEg: the hours hand is on 12 , I want to display 6 , sure I can wait 6 hours for it to become 6 , then cut the power off via a mosfet to let the "6" stay , or I can change they crystal frequency (via pwm of course, no crystal is there) so it moves in 1 min from "12" to "6"Now I don't know very much about clocks , or how theyexactly works (the absolute specifics), so I might be wrong ,no need for watch makers/lovers/engineers/collectors to send a hitman to my locationHere is a picture for my "cheap Chinese analog clock" , it is also a silent clock , that means the seconds hand doesn't do the "tick tick) every second , it just moves smaller steps (like 5 or 10 each second) , so it appears like it is constantly moving instead of jumping from one second to anotherAny suggestions / advice ?I really doubt the second way of doing this , is it possible to implement it that way?also I'm going to make another thread about a list I've made for my weird number displays hobbyin case there someone with similar weird hobby that wants to add to the listThanks in advance !

author: RJSV
author_rank: Super Contributor
timestamp: March 30, 2025, 01:02:59 am
content: Nice thinking on your part, OP !A humourous and campy display Could feature a woman with 1 puppy, then 2, in her arms.s, etc. Curtain to hide for a few seconds, while the dogs get changed ,

author: RJSV
author_rank: Super Contributor
timestamp: March 30, 2025, 01:49:00 am
content: If you can picture; a pipe pointing upward, but ready mounted for a pivot, slowly downward, and that could be a TEN MINUTE TIMER, filling up with colored water.So, in that you get an ANALOG gauge. Might have to be large for visibility, maybe 50 cm.A person could glance at that, and see the water, and see the pipe angle declining as it fills (against spring).Ah, but too low and that pipe dumps, th.en travels back by rotating back to pointing up.But too many 'leaning' pipes gets cluttered, maybe 2 is max. That gets you up to'59'.You want, maybe, a good quick glance resolvable, maybe try:'USPTO'. That's patents and trademarks.That office uspto.gov has lots of search help, so you could spend time getting ideas.0As stated, displays for vehicles and fast airplanes are in demand: maybe try to explore making some income. Although that can be a trap, if unrealistic.(Sorry about text glitches...broken touch screen.)- - Rick Bastian

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 30, 2025, 07:27:47 am
content: Quote from: osmax_br on March 29, 2025, 10:07:23 pmBroadly, yes.There will be some upper electro-mechanical limit on the motor stepping rate (which might also be stretched with higher voltage)An oscilloscope would help here.You would need to determine that for each individual clock experimentally.MCUs are quite good at generating precisely timed pulses, via their timers, and the timing is easily changed.eg you could take a clock at any wrong time, and enter the correct time and current wrong time, and have the MCU generate a known number of faster pulses to play catch up.You could also have the MCU pause-&-Wait, if the current time was found to be slightly ahead of the correct time.Some mechanisms might allow you to run backwards.QuoteSounds nice. It is also easy to generate 5~10 pulses every second from a MCU.

author: SteveThackery
author_rank: Super Contributor
timestamp: March 30, 2025, 11:46:51 am
content: THERE'S A TL:DR AT THE END!I've done quite a lot of work with the ubiquitous quartz clock movements found in almost all modern clocks, in particular making them run at different speeds.Put simply, yes, you can change their speed, but there are complications. There is an upper limit to how fast they will go, which is still frustratingly low for rapid advancing of the hands. Also, although the motor is designed to run only in one direction, at certain speeds there is enough torsional vibration in the gear train to "flip" the motor into running backwards. You can avoid this by applying some frictional resistance to the second hand, at the cost of reducing the maximum forward speed.Rather than applying different frequencies to the crystal input on the built-in chip, it is very much better to cut the tracks to the motor coil and drive it yourself from a microcontroller. You need two output pins to drive the motor because it uses alternating polarity pulses. Thus at rest the pins can both be 0,0 or 1,1. To run the motor you just invert each pin alternately for a few milliseconds. The advantage of a microcontroller circuit is that you have full control over the motor drive: the voltage, the frequency and the pulse duration. Plus you can incorporate whatever fancy features you like in the software.There is another fundamental limitation of using the bog-standard quartz clock movement: there is no positional feedback from the hands (but see later). Thus if you are fast-forwarding the movement (say) and it skips some steps, your microcontroller won't know and the clock will then have a fixed offset from the time it should be showing. However, you can buy radio-controlled quartz clock movements, and thesedohave positional feedback - of sorts. The "of sorts" is because they typically only provide positional feedback at one position* - 12 o'clock. Thus errors can persist for up to 12 hours before you get a chance to pick them up and apply correction.*Some of my clocks appear to know when they are at 4 o'clock and 8 o'clock, as well as 12, but I haven't explored exactly how they work.A third option is to buy a quartz mechanism that incorporates a strike or chime feature. I have done no work with these, but obviously there must be some kind of positional feedback from the hands to trigger the strike or chime. I don't know if this is once per 12 hours and then it uses dead reckoning (pulse counting) to decide when to chime over the next 12 hours, or if there is some kind of hourly feedback. It might be worth checking one out.IN SUMMARY:1/ Yes quartz clock movements can be made to run much faster than normal, but there is a limit to how fast they will go which, for many purposes, is still frustratingly slow.2/ Due to resonances in the gear train, the movements may run backwards at certain speeds. Frictional damping of the second hand mitigates against this.3/ It is recommended to run the stepper motor from your own microcontroller circuit because you then have full control over the voltage, duration and frequency of the pulses. The pulses must alternate in polarity.4/ Normal quartz clock movements have no positional feedback from the hands so stepping errors can occur and accumulate undetected. Radio controlled movements, and striking/chiming movements, can detect the position of the hands, but only at set intervals, not continuously. In all cases you will need to dig into the mechanism and circuit to discover how it works.

author: SteveThackery
author_rank: Super Contributor
timestamp: March 30, 2025, 11:51:47 am
content: Just one other point: people have been thinking up novel ways of displaying the time for absolutely ages. You can sometimes find these novelty clocks on eBay or the Chinese outlets. They might be useful for inspiration, but you might find it hard to come up with an idea which hasn't been tried before.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 30, 2025, 01:12:38 pm
content: Quote from: SteveThackery on March 30, 2025, 11:46:51 amMost RC clocks I've seen can't detect the hands, you simply have to set it at the 12 position when powering up. Which is a lot cheaper of course

author: ledtester
author_rank: Super Contributor
timestamp: March 30, 2025, 02:37:03 pm
content: A recent video on pulsing a quartz clock mechanism directly:How to Create a Crazy Analog Clock! -- Playful Technologyhttps://youtu.be/v142dbmIYq0Was able to get a clock to run at 100x normal speed.Also, there's discussion on how to pulse the clock to get it to run backwards. Since the cog rotates 180 degrees on each pulse you have to set up a preference for it to rotate clockwise or counter-clockwise.And a second video on the same channel on making a WiFi controlled clock:I made REMOTE CONTROL clock hands using an ESP8266 over Wi-Fi! -- Playful Technologyhttps://youtu.be/K5sB2GNunMY

author: 5U4GB
author_rank: Super Contributor
timestamp: March 30, 2025, 03:47:45 pm
content: My immediate reaction was the same as@RJSV's, some sort of fluid-based indicator. For example a Galileo thermometer could be used to display digits 0-9 under electronic control via a heating element, admittedly with a rather long response time.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 30, 2025, 06:20:58 pm
content: Google finds this, which has waveforms for the OP.https://www.renesas.com/ja/document/apn/cm-241-analog-clock-motor-driverThat shows 10ms alternating pulse.You can get a wider range of packages for reflective optical sensors but that mean finding a place to drill or glue the sensor, and an outward looking sensor would likely struggle with all ambient light environments.A slotted sensor would be much more predictable but harder to mount and hide.Tiny Slotted Opto Example: GP1S396HCPSF ・Gap Width : 1.2mm ・Slit Width (detector side) : 0.12mm ・Package : 2.26 × 1.4 × 1.6mm (26c at lcsc)Addit maybe a reflective modulated sensor can be made ambient tolerant enough ?Examplehttps://www.tti.com/content/ttiinc/en/manufacturers/tt-electronics/products/tt-electronics-opb9010-reflective-optical-sensors.html

author: tggzzz
author_rank: Super Contributor
timestamp: March 30, 2025, 06:25:03 pm
content: Weird and (sometimes) wonderful clocks and display mechanisms crop up regularly on Hackaday. I suggest you search for "site:hackaday.com clock" and similar.

author: SteveThackery
author_rank: Super Contributor
timestamp: March 30, 2025, 09:33:47 pm
content: Quote from: PA0PBZ on March 30, 2025, 01:12:38 pmThe ones I've got do detect the position of the hands. Or more specifically, the position of the gears. The relevant gears each have a hole in them, and a light sensor is illuminated by an LED on the other side of the gears when all three holes line up - once per 12 hours (to the second). When the movement is delivered the train is locked at 12:00:00 with a pin. The user must fit all three hands pointing exactly at 12 before removing the pin. That way, whenever the holes are aligned, the hands are correctly positioned at 12:00:00.The LED/sensor system is only powered up when the mechanism is looking for the 12 o'clock position. Once found, the LED is switched off and from then on the clock uses pulse counting to determine where the hands are.For example, when a new battery is fitted and the hands are showing some random time, the hands are motored to the 12:00:00 position whilst simultaneously the radio receiver is listening for the time signal. The hands stop at 12:00:00, and when the radio time has been received they are motored to the right time using pulse counting. Normal running then commences.

author: osmax_br
author_rank: Regular Contributor
timestamp: March 31, 2025, 01:05:53 pm
content: Quote from: SteveThackery on March 30, 2025, 11:46:51 amDude you are a legendThanks you for the detailed replyAt this point I'm really curious to know what motivated you to do experiments on the clocks mechanisms and quartzFor the feedback I'm thinking of 2 ways1- the way you've mentioned , my alarm clock has an alarm hand , once it reaches the desired time a signal is transferred to the ringing motor , I simply need to read the signal to adjust my time, however the alarm function can be quite inaccurate in these clocks and sometimes it doesn't trigger2- place a small magnet on the hours hand , and place hall effect sensors of different parts of the clock , 12,3,6,9 etc..... , I guess this would be a more accurate way , however I doubt that I can find such a small magnet that can fit on the small hours hand and at the same time be powerful enough to trigger the sensor behind the cardboard dashboardA radio controlled clock , huh ? , I guess they are not available in many countries world wide , I've never heard of them except on a Tom Scott video a few years ago , never seen one in my life , the radio frequency transmitted by the government, isn't it?And sorry for the late reply

author: osmax_br
author_rank: Regular Contributor
timestamp: March 31, 2025, 01:08:02 pm
content: Quote from: SteveThackery on March 30, 2025, 11:51:47 amI'm a fan of these vfd displays , but I have better things to spend 40$ on lol

author: osmax_br
author_rank: Regular Contributor
timestamp: March 31, 2025, 01:12:32 pm
content: Quote from: 5U4GB on March 30, 2025, 03:47:45 pmOr we can simply use hydraulic pressure instead of the energy-consuming heating elementWe can also use capillary tube used in taking blood samples for testing , however finding a mechanism to empty the filled tube might be a bit challenging

author: osmax_br
author_rank: Regular Contributor
timestamp: March 31, 2025, 01:21:58 pm
content: Quote from: Simmed on March 30, 2025, 03:54:12 pmI'm thinking also of a huge 7 segment displayWe make a big square of individual 7 segment displays , the width is 7 displays and the height is 7 displays for a total of 49 7 segments , multiply 7*49 and you have 343 led to controllNow you can display the full alphabet and even some harder characters like Arabic alphabetWiring to the shift registers manually would be a nightmare lol

author: themadhippy
author_rank: Super Contributor
timestamp: March 31, 2025, 03:14:30 pm
content: Quotebeen there ,done that ,each segment was a florry tubeAs for unusual clocks my favorite had no hands,the face rotated,

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 31, 2025, 07:56:09 pm
content: Quote from: ledtester on March 30, 2025, 02:37:03 pmThat's impressive.I wonder how it looks to the eye, if you can run that at 100x, but pause 40% of the time at the correct second location ?That gives one second per revolution, and the pause location walks at a lower 60 steps per revolution.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 31, 2025, 08:45:17 pm
content: Quote from: osmax_br on March 31, 2025, 01:05:53 pmIf that was impractical, a reflective opto sensor might work. example :https://www.vishay.com/docs/80223/vcnt2030.pdfThese are available quite small (designed for ear-bud fitted sense), with an emitter-detector separation of just over 1.0mm, so a small hole would be enough.A tiny concave mirror/reflective tape on the hand rear side, could help optical gain.You can also modulate the LED, and feedback bias the photo transistor to make it much more tolerant of incident light.Quote from: SteveThackery on March 30, 2025, 09:33:47 pmThat's clever, but needs a very custom mechanism.You might have room to fit optical sensors to the larger gears in a more standard mechanism.Slotted sensors come in multiple width/depth choices these days.A single small, drilled hole would give one update per rev, or you could drill 1 + 2 holes or 1+2+3 grouped holes.The small GP1S396HCPSF I posted above, has a slit width of just 0.12mm, so it could be carefully positioned to sense the gear teeth, giving a modulated output.

author: bdeianov
author_rank: Contributor
timestamp: March 31, 2025, 09:38:45 pm
content: Quote from: SteveThackery on March 30, 2025, 09:33:47 pmThis description sounds exactly like the CH899 movement I've been playing with. I'm curious if you are talking about the same one, or if there are others of this style.https://www.hr-clockparts.com/clock-movement/wifi-clock-movement.html

author: Andy Chee
author_rank: Super Contributor
timestamp: April 01, 2025, 07:46:32 am
content: It might take a bit of learning to interpret and translate, but how about programming some WS2812 leds to smoothly change colour, with each colour corresponding to the hour/minute/second?https://flora-magazine.com/wp-content/uploads/2025/01/basic-colour-wheel-1.png

author: SteveThackery
author_rank: Super Contributor
timestamp: April 01, 2025, 10:57:32 am
content: Quote from: bdeianov on March 31, 2025, 09:38:45 pmActually, no, I was referring to a much more primitive device. This is an example of what I was talking about:https://amzn.eu/d/es64wHsIt receives the 60kHz radio signal (call sign MSF) broadcast in the UK as its time reference. There are others available for the other radio time signals around the world.*I must emphasise that I have never used the particular movement linked above - it is just an example of what I was talking about.______* ChatGPT has dug out ten radio time signals around the world. I'll copy its findings here in case anyone is interested.EuropeDCF77 (Germany) – Located in Mainflingen, near Frankfurt, operating at 77.5 kHz.TDF (France) – Transmitted from Allouis on 162 kHz (previously used for France Inter radio).North AmericaWWVB (USA) – Operated by NIST in Fort Collins, Colorado, broadcasting on 60 kHz.CHU (Canada) – Transmits time signals on 3.33 MHz, 7.85 MHz, and 14.67 MHz in the shortwave band.AsiaBPC (China) – Broadcast from Shangqiu, Henan, on 68.5 kHz.JJY (Japan) – Operates from two locations: Mount Otakadoya (Fukushima) on 40 kHz and Mount Hagane (Kyushu) on 60 kHz.RTZ (Russia) – Located in Irkutsk, transmitting on 50 kHz.South AmericaHBG (Switzerland, now discontinued in 2011) – Previously operated on 75 kHz.YVTO (Venezuela) – Shortwave time signal transmitted on 5 MHz.OceaniaVNG (Australia, now discontinued in 2002) – Previously broadcast on multiple shortwave frequencies.Many of these radio time signals are low-frequency (LF) transmissions, typically in the 40-80 kHz range, allowing for long-distance propagation with high accuracy. Some countries also operate shortwave time signals, which can be received globally under good conditions.

author: SteveThackery
author_rank: Super Contributor
timestamp: April 01, 2025, 11:01:35 am
content: Quote from: PCB.Wiz on March 31, 2025, 08:45:17 pmI think you mean complex rather than custom. I don't disagree, although they aren't massively expensive.

author: SteveThackery
author_rank: Super Contributor
timestamp: April 01, 2025, 11:08:50 am
content: Quote from: osmax_br on March 31, 2025, 01:05:53 pmIn my post up the page just a bit you will see I have listed 10 radio time signals from around the world. It isn't always the government itself that transmits the signal - for instance in the UK the transmitter is operated by Babcock International Group on contract to the National Physical Laboratory (NPL).

author: SteveThackery
author_rank: Super Contributor
timestamp: April 01, 2025, 12:02:39 pm
content: If you will permit me, I just want to emphasise a point. Basic quartz clock movements have no feedback from the hands (or gears) back to the electronics, so they operate "open-loop" all the time after the user has positioned the hands. They work brilliantly - over a two-year run they will step 63 million times, usually without missing a single step.However, if you want to operate them at non-standard speeds, or with different pulse durations or voltages, the chance of mis-stepping is obviously higher, which is why you should consider finding one with some sort of feedback such that the electronics can detect and correct any error in the displayed time.The only ones I have any experience of are the radio controlled movements available up to around eight years ago. I cannot speak definitely about the current models. The radio controlled ones I used had feedback from all three hands (because accuracy to the second was required). However, I urge you to investigate the movements with an alarm function (feedback signal presumably every 12 hours) and those which strike or chime (feedback presumably every 15 minutes or every hour).Quote from: osmax_br on March 31, 2025, 01:05:53 pmAn artist approached me through my professional body (the British Horological Institute) to assist with some art works exploring time. One required a hand to rotate once every 100 minutes, for example, and another to rotate once every ten hours. I can't remember the details, but she asked for various shenanigans related to displaying the time, and also "warping" time so it ran at different rates.You may not know much about "master clocks", which were widely used through the 20th century in factories, schools, railway stations and office blocks where it is important that all the clocks show the same, correct, time. (This is before affordable quartz clocks were available.) These master clocks were typically high quality, electrically operated pendulum clocks - probably the most famous makes in the UK being Gents and Synchronome. Other makes include Smiths, IBM and Magneta. Most master clocks send out pulses every 30 seconds or 60 seconds via wiring to the slave clocks, which usually incorporate a simple stepper mechanism.People (like me!) collect master clocks. Slave clocks are getting scarcer and more expensive, so sometimes it is fun to adapt a modern quartz movement to run off the pulses from a master clock. I've done two approaches: the first being to pulse the motor imperceptibly faster than once per second, and after 30 motor pulses wait for the pulse from the master clock to synchronise to. If you do this well you can make the pause every 30 seconds virtually unnoticeable. This method works great if you want to keep the second hand.If you are willing to do without the second hand, you can modify this approach. Each time a pulse is received from the master clock, send 30 rapid pulses to the stepper motor and then pause. Repeat at the next pulse. This looks cool as every 30 seconds the minute hand moves smoothly through half a minute. My favourite is to do this everytwo30s pulses from the master clock, so that every minute the minute hand moves smoothly to the next minute marker over a period of two or three seconds (depending on how fast you can drive the motor reliably).In general, any time display where you want to use hands in the traditional 60:60:12 relationship is a candidate for using a hacked quartz clock movement. This is because for a few pounds or dollars you get all the necessary gearing to drive the hands in the traditional seconds:minutes:hours relationship AND these hands are mounted concentrically. To build the necessary gearing yourself from scratch is a VERY BIG job which involves lathe work and cutting several gears.Phew! Sorry - too many words.

author: tggzzz
author_rank: Super Contributor
timestamp: April 01, 2025, 12:04:48 pm
content: Quote from: SteveThackery on April 01, 2025, 12:02:39 pmI used similar techniques (but diddling the 50Hz mains timing signal) when converting my homemade (in 1973!) digital clock to be a Vetinari clock.https://entertaininghacks.wordpress.com/2015/02/23/vetinari-digital-clock/

author: SteveThackery
author_rank: Super Contributor
timestamp: April 01, 2025, 12:18:37 pm
content: Quote from: tggzzz on April 01, 2025, 12:04:48 pmVery cool!

author: Tation
author_rank: Regular Contributor
timestamp: April 01, 2025, 10:41:12 pm
content: Quote from: SteveThackery on March 30, 2025, 11:46:51 amYears ago I myself embarked in a kind of "astronomical" clock project, showing: HMS; day of week; day of month; month; moon age; sunrise and sunset; and seasons. It used some 8051 variant, programmed in C, and 6 or 7 (cannot remember exactly) cheap quartz movements to show all these, all driven directly from the μC (as you say, differentially with 2 wires for each movement). Used many equations from thisbookfrom Jean Meeus. The chip I was using was a 8-bitter with tight memory and performance, so many approximations were needed in computations. The moon age calculations where the hardest ones, as precise computations were costly.In any case, I wrote this because the interesting part is that I thought about means of running the movements backwards, and found a way to do it that, maybe, is different from that one your describe. I was able move them backwards at any speed (up to a maximum one, of course, similar to that of fordward movement).The usual way to drive these movements is applying sort pulses of alternating polarity. This(from 02:25) describes the Lavet motor, the drive usually in this quartz clock mechanisms. The usual waveform is:Code:+-----+| || |-----+ +-----------+ +-----| || |+-----+and the wavefor I applied to move them backwards was:Code:+-----+ +-+| | | || | | |---+ + +---------+ + +-----| | | || | | |+-+ +-----+The short pulses in front of the "main" pulses return the rotor to the center (polarized) position from the unpolarized position, inertia allows the rotor to pass such center position and, then, the main, wide, pulses turn it 180º, but in the "wrong" direction.Is this the way you used to move them backwards?

author: themadhippy
author_rank: Super Contributor
timestamp: April 02, 2025, 01:06:10 am
content: Thanks to this thread i fell down the rabbit hole of strange clocks,this one especially appeals

author: SteveThackery
author_rank: Super Contributor
timestamp: April 02, 2025, 08:55:04 am
content: Quote from: Tation on April 01, 2025, 10:41:12 pmVery nice idea! I found that the choice of second hand made a big difference when running backwards - it has a significant effect on the torsional resonant frequency, and that affects the speed at which the movement will run backwards.But my method was always a bodge, and I think your idea is way better. I can imagine different makes of movement might need the "pre-pulse" to be optimised in terms of duration. Also, I suspect it might be worth experimenting with a brief interval between the pre-pulse and the main pulse.I love it, and I'm annoyed with myself for not thinking of it!

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 02, 2025, 10:17:36 am
content: No mention of what frustratingly slow actually is, but I am guessing that speeding it up by a factor of a hundred is in the neighborhood. And the only way to reduce the value on the display is to run it forward through the entire 12 "hour" cycle, so about seven minutes.Might be fine for displaying tide cycles but pretty limited.If you want this type of display I would go back to the mechanical roots. Have concentric shafts (brass tubing for the outside shafts). And have a stepper motor for each shaft. Each hand can then be driven independently, and they can be driven backwards as required. Indexing is much easier. This approach doesn't have to be expensive. Small steppers can be salvaged from many sources, and the drive could be muxed.This concept could be extended to several digits, using something other than length of the hands to distinguish the decades. Color for example.

author: SteveThackery
author_rank: Super Contributor
timestamp: April 02, 2025, 08:50:30 pm
content: Quote from: CatalinaWOW on April 02, 2025, 10:17:36 amYeah - it takes 36 seconds to advance the clock by an hour, which for most purposes still seems glacially slow.Your suggestion to drive the three hands each with their own stepper motor is obviously better, but if course it adds way more complexity and needs some mechanical engineering, unlike the method we've been discussing.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 02, 2025, 09:01:28 pm
content: Quote from: SteveThackery on April 02, 2025, 08:50:30 pmAs always, there is a trade between simplicity and results. The is some bodging required for the approach I suggest, but it could be implemented easily with a drill, an Exacto saw and some hot glue. Or done elegantly by adding a 3D printerIt all really boils down to what interests you

author: SteveThackery
author_rank: Super Contributor
timestamp: April 03, 2025, 12:41:10 pm
content: Quote from: CatalinaWOW on April 02, 2025, 09:01:28 pmHaving three separate mechanisms on three separate axes for the hands does, of course, make it easy. I was thinking of the situation where all three hands are on the same axis, like a normal clock. Much more challenging. I'm sorry I didn't make that clear.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 03, 2025, 02:58:22 pm
content: Quote from: SteveThackery on April 03, 2025, 12:41:10 pmI was proposing a coaxial design. The availability of brass tubing in nesting sizes makes this relatively easy. If I get time over the next week or so I will throw together a FreeCad model

author: SteveThackery
author_rank: Super Contributor
timestamp: April 03, 2025, 09:00:20 pm
content: Quote from: CatalinaWOW on April 03, 2025, 02:58:22 pmIf you could 3D print the gears it would make life much easier, compared with cutting them in the traditional way. That will, indeed, make it relatively easy.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 03, 2025, 09:53:34 pm
content: Or purchase them. There suitable assortments on Amazon and others, 50 plus gears for under $10.

author: Tation
author_rank: Regular Contributor
timestamp: April 03, 2025, 10:01:00 pm
content: The horizontal "thermometer" of the dashboard below is a speedometer, graduated in km/h. The red bar glowed in orange when lights were switched on.I suppose that this kind of display was common then (the car was a SEAT 1400C, a spanish car from 1960 and, incidentally, grandpa's car), although I have not seen it in other cars. I am still wondering how it worked...

author: SteveThackery
author_rank: Super Contributor
timestamp: April 04, 2025, 09:24:56 am
content: It was used in several BMC (British Motor Corporation) cars of the '60s.Courtesy ofhttps://www.flickr.com/photos/35707376@N00/52701544857

author: SteveThackery
author_rank: Super Contributor
timestamp: April 04, 2025, 09:26:20 am
content: Quote from: CatalinaWOW on April 03, 2025, 09:53:34 pmAh, yes, an excellent suggestion - I had forgotten about those.

author: Picuino
author_rank: Super Contributor
timestamp: April 04, 2025, 10:33:38 am
content: I remember a wristwatch for the blind that told the time with beeps. That might be an option. Or with different melodies.Taking the idea to the extreme, you can tell the time with morse code by beeps (extremely geeky).

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 14, 2025, 04:45:35 am
content: So I had a free hour tonight and threw together a crude model of the coaxial concept based on nested brass tubing. The PDF is the easiest thing to attach on this forum.The concept has an outer brass tube which is fixed in the display face. Stepper motors drive the three hands. Hands and the gears are fixed (glued) to the appropriate tubes providing all the location control required. Mounting of the very conceptual stepper motors is left until someone picks the appropriate motors from their parts bins. Pointers could be easily 3D printed.If anyone is really interested I can post the FreeCAD file so you can fill in the details needed. It would be relatively easy to extend to 6 digits if desired, but beyond that packing the gears and stepper motors gets interesting.

author: SteveThackery
author_rank: Super Contributor
timestamp: April 14, 2025, 10:20:59 am
content: Quote from: Picuino on April 04, 2025, 10:33:38 amI've just remembered - at one time (and probably now?) you could buy clocks that "chimed" a bird song on the hour.We have gone away from original question, I think, because I think the OP wanted something that provided a continuous display of the time. Continuous beeping would drive anybody nuts!

author: bson
author_rank: Unknown
timestamp: April 14, 2025, 06:54:35 pm
content: Robotic sundial: move a light around the dial. Factor in seasonal changes.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 14, 2025, 08:04:16 pm
content: Quote from: bson on April 14, 2025, 06:54:35 pmI like the idea. For those who haven't seen it, look up the 3D printed digital sundial. Adding a servo controlled two axis tilt platform to compensate for seasonal variations would be suitable geeky. Further including a light on a robot arm for nighttime and cloudy days would be icing on the cake.