Awesome Clock  - Page 1
Forum section: electronics / general

author: veryevil
author_rank: Unknown
timestamp: September 21, 2014, 07:52:50 pm
content: Just seen that and I think its awesome. I cannot find any information on the creator would love to see how it was made.

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 21, 2014, 08:34:53 pm
content: http://www.humanssince1982.com/a-million-times

author: veryevil
author_rank: Unknown
timestamp: September 21, 2014, 09:39:40 pm
content: Ha ha it just appeared onhackaday!

author: Willy.nebula
author_rank: Newbie
timestamp: September 22, 2014, 12:20:31 am
content: That "is" awesome

author: TerraHertz
author_rank: Super Contributor
timestamp: September 23, 2014, 10:42:34 am
content: Wow, beautiful. I'm very jealous that he figured out how to implement this so well. Both the mechanics and software for this are hard.I wanted to save local copies of the video. Search vimeo for "a million times" found:vimeo. com/60491636 A million times (Time Dubai) by Humans since 1982 The originalvimeo. com/60333036 Humans Since 1982, a million times Similar, copied by someone else. Silentvimeo. com/60824954 A MILLION TIMES Another. different view and musicAlso Anna von Hausswolff - Mountains Crave youtube. com/watch?v=QbP--RsNj70]Music to the 'a million times' clockI've wanted to make an analog clock with independently, identically driven hands for ages, but the mechanics is hard in a hobby workshop. Needs two identical fine gears on the sleeved hand-drive shafts, with worm gear drive from tiny stepper motors (such as used in floppy disk drives.) A bit beyond my machining abilities, and so far I didn't find anything suitable commercially.But the really tricky part is arranging separate index sensors for both gears, with sufficient accuracy to allow the hands to be lined up visually perfectly. Since the eye is so damned good at sensing a slight kink in a line, the index sensor has to be accurate to a tiny fraction of a degree. it's noticeable that some of the hands in that array are a little off sometimes, so I guess he didn't entirely solve that either.I wonder if he's using a separate small processor per unit? It seems likely. Perhaps with unit IDs that are an X,Y coordinate, and a command broadcast syntax that allows description of 'waves' across the X,Y space, so individual units figure out for themselves what they need to do.(Edited to stop the auto-URL insertion of videos. Remove spaces.)

author: Precipice
author_rank: Frequent Contributor
timestamp: September 23, 2014, 10:49:00 am
content: Quote from: TerraHertz on September 23, 2014, 10:42:34 amCoaxial stepper motors -http://www.jukenswisstech.com/?page_id=105Although those have a mechanical stop, for their intended application.You can also get steppers with hollow shafts, which solve some of your problems.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 23, 2014, 10:57:01 am
content: Quote from: Precipice on September 23, 2014, 10:49:00 amNo, useless for this application, because the step size totally won't be fine enough. For the visual smoothness and ability to gradually shift speed, it has to be a fine increment stepper, driving the hands via a worm gear. With no play - but that's easy enough.For lowest cost too, standard steppers are a must. In my case I'm thinking of a commercial 'clock-like' application (which is also kind-of art), so mass production is a requirement.The indexing problem really is the hardest part. Also it has to be adjustment free, and since the hands get pressed onto the round drive shaft/tube, that effectively means you have to sense the actual hands position (at one point), not the drive gear at the rear. Without any visual sign of the index sensor. So, a magnetic induction thing through the plastic clock face, perhaps. But then accuracy is a bear...

author: Precipice
author_rank: Frequent Contributor
timestamp: September 23, 2014, 11:05:07 am
content: Ditch the local feedback and train it with a webcam?(Microstepping should get you a bearable smoothness, even with quite crappy steppers)

author: TerraHertz
author_rank: Super Contributor
timestamp: September 23, 2014, 11:35:45 am
content: Quote from: Precipice on September 23, 2014, 11:05:07 amThen you can't stand in front of the clock. The indexing ability needs to be there at least at every power-up. Also preferably as a sanity check all the time. Not to mention the huge complexity increment of including camera, image capture and analysis software (and a processor that can handle it.)QuoteThen you can't stop applying power to the steppers when the hands are static. For the intended application, minimal power is a must.There's nothing wrong with a couple of simple plastic gears on the hands shafts, and small worm gears on the stepper shafts. If they are mass produced.

author: Precipice
author_rank: Frequent Contributor
timestamp: September 23, 2014, 11:49:48 am
content: You only have to buy the webcam once, rather than fitting the indexing gear onto every instance, which makes it a little more appealing. Also lets you play fun games by drawing outlines of visitorsMaking plastic gears isn't too hard - mill one, copy by moulding. Make it from toothed bar stock if you can't face milling teeth, or just buy and modify some gears, then copy them by moulding.http://www.hpcgears.com/n/products/15.toothed_bar_stock/toothed_bar_stock.phpThe gears you'd need for this wouldn't be too hard, and if you were careful, you should be able to enforce the hands lining up with features on the gears, so you can do your indexing from the back. Just use plastic on plastic bearings, with a bit of plastic grease, for longevity and a bit of smoothness. So now you're down to 2 steppers, a pair of worm gears, a pair of big gears, maybe a bushing to get you through the clockface? Then the hands and indexing stuff. If you were making this in volume, the plastics would be well sub $1, including a frame to hold the steppers and a PCB.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 24, 2014, 08:17:26 am
content: Quote from: Precipice on September 23, 2014, 11:49:48 amYou're thinking 'one-off installation with many clocks, in a gallery', just like the Million Times video. But the application I'm thinking of is almost identical to a traditional clock. Needs to be mountable anywhere, by anyone, work for years, draw very little current, and be mass produced cheaply. There just isn't going to be any video camera. Let alone ability to mount and wire one up.One solution to the indexing problem is just to have a second set of hands, inside the body. Then you only need one optical interrupter sensor, since each hand can be indexed separately while the other one is out of the way. Have both hands pass through the one sensor slot. Use a jig to fit the hands to the shafts in exact alignment front to back. It's a little bit annoying that the inside hands have to be mounted on the gears, and be profiled to have clearance for the worm gears, steppers, etc.QuoteThe toothed bar stock is news to me, thanks. Didn't know such a thing existed. The rest- yes, agreed. Apart from injection tooling costs.This project is one of many on my list to pursue once my workshop is completed. Hence not currently pursuing things like low cost suppliers of gears. Oh, and a 3D printer is on the tools list, for things like prototype frames to hold bushings, etc.

author: Precipice
author_rank: Frequent Contributor
timestamp: September 24, 2014, 08:59:48 am
content: One thing I often ponder, but very rarely seen done, is having a constantly rotating shaft, with clutches to engage or disengage for rotation.You'd need proper position sensing (index pulse and quadrature) for each hand, but only a solenoid per, rather than a stepper. Two solenoids, if you wanted bidirectional. (I'm imagining you having a splined shaft with a load of spur gears, and pressing, or not, them against the gear with the hands attached.)But little steppers are so cheap...http://www.aliexpress.com/item/NEW-10pcs-Japan-Nidec-Mini-stepper-motor-micro-stepper-motor-2-phase-4-wire-D6mm-stepping/1612405669.htmlorhttp://www.aliexpress.com/item/10pcs-New-DC-3v-2-phase-4-wire-micro-step-motor-20-mm-Mini-stepper-motor/1799485746.htmlif you need a bit more force.

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: September 25, 2014, 12:24:45 am
content: I have several radio controlled analogue wall clocks, and they control the hands separatelyThe minute hand only steps every 15 seconds, it's not a smooth transition, but a clunk for each 15 second step, the second hand moves independently from the minute hand when initially putting in the battery. On power up, it moves the second hand to 12, then moves the minute hand to 12 and the hour hand to either 3, 6 or 9, whichever is the closer in the clockwise direction. Then it sits there waiting to lock onto the minute marker and off it goes.There unmarked so make is unknown

author: PointyOintment
author_rank: Frequent Contributor
timestamp: September 25, 2014, 01:28:03 am
content: Quote from: TerraHertz on September 23, 2014, 11:35:45 amThe hands don't need to stop on a microstep. The only positions that really matter are 0°, 90°, 180°, and 270°. The angles for the clocks that aren't participating in displaying numbers don't need to position their hands at particularly precise angles.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 25, 2014, 07:30:52 am
content: Quote from: PointyOintment on September 25, 2014, 01:28:03 amYou're still thinking 'clock'. Take another look at the videos. When there are 'force field' type arrangements, they certainly do need precise angle positioning. Any that are even slightly off will stand out like dogs balls.Same thing with any 'organic' style motion - the human eye and brain are very good at spotting discrepancies. Something that is slowing down to a stop (especially with 'S curve' deceleration) can't just suddenly glitch a little bit at the end to the nearest unit step position of a 1.8 degree or whatever stepper motor.Anyway, enough of the details. The application is a cross between utility (clock, sometimes) and art. So the requirements are complex. Not worth going into further.