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Everything posted by AndyHull

  1. This arrived in one of my many feeds. It describes how to use Inkscake for tessellations (repeated tilling of the 2D plane with less than obvious shapes). https://www.instructables.com/Quickly-Sketch-Escher-type-Repeats-Using-Inkscape/ There is scope for combining this with rotations to produce some very interesting circular designs. I'll need to look in to it in more depth when I get a spare moment, but I thought I'd share it here in the hope that it might provide some inspiration. On a related note, there is also this work by Michelle Chandra which uses a plotte
  2. ".. If you are going to survive out there, you've have really got to know where your towel is.." In one of life's more surreal moments, I got a delivery through the post of one of those nondescript Chinese polythene packages. There is nothing particularly odd about that, given my tendency to order random things from half way round the planet. However the label on it stated "1 x Towel". "What? I didn't order any towel?" I thought, so assuming it was simply some way of ensuring that some bored customs officer didn't bother to check it, and that it probably actually cont
  3. A rather scruffy Casio CS-831 is on its way. Released in 1983 with a stainless steel case, and Casio build quality, these were arguably the must have calculator watch of the day, and one of those gadgets that I nearly bought, back then but couldn't justify the price for at the time. Well there is no problem with the price of this one, it easily will make it in to the 404 club, assuming I can get it working and make it look a little more presentable. I'm not sure the bracelet is original, but I have a couple of suitable Casio bracelets in the junk pile if it isn't.
  4. I took a look at the mechanism today, and naturally the coil was open circuit. This might have proved an insurmountable issue as I was unlikely to be able to source a new coil. Since a google search of "wtl-m2-50-230-600" produced nothing I figured it was worth stripping down the existing one and taking a look for the source of the problem. It turned out to be a dry solder joint, which was pretty simple to remedy. If you look closely you will see that the coil consists of three thin conductors (wires) rather than a single larger diameter conductor. Th
  5. Well the Dumbarton Westclox arrived recently, and spent a couple of days in Covid quarantine, so today I had a quick crack at addressing its more obvious cosmetic issues. The bezel, it turns out, was, at some stage in the dim and distant past, polished brass. The ebay pictures had me thinking it was probably nickel plated, but that was just the result of many many years of neglect. I didn't even check the coil, I'll take a look at that, and servicing the mechanism next. The process for removing the bezel and glass in order to remove the filth on the inside, was less than obvi
  6. Here's one for all the electro-mechancal clock fans, and fans of Russian horology everywhere. ... and if you enjoy that, you might like to take a look at his earlier series on the electronic version here. Actually most of CuriousMarc's videos are worth a look, so you might want to spend some time browsing through some of his other stuff. There are lots of bits computer history and electromechanical calculator stuff too.
  7. Not another Metamec, but it is a synchronous mains clock. This time a Westclox for the bargain bin price of £2.99. From the styling I would guess perhaps the late 1950s, but I can't be certain. It doesn't have a "starter" mechanism, so it won't be earlier than late 1940s I would think. The woodwork needs a little TLC and someone has snipped off the mains cable, so it probably needs some internal work too. It will certainly need a service, so lets see if I can bring it back from the scrap heap without resorting to fitting a quartz mechanism. I did see a similar one here, m
  8. They are dashed cunning.. you don't detect anything till they activate it. https://en.wikipedia.org/wiki/The_Thing_(listening_device)
  9. I'm posting this here as I think it will be of interest to anyone working with radium dials and watches. I would suggest that there is actually very little measurable risk from handling a few radium watch hands, so long as you wash your own hands afterwards, and make sure that you don't grind up significant amounts of the material and release it in to the air. The point here being that you would need significant amounts. Grams of dust, not a few microgrammes. You have to bear in mind that the materials involved are indeed radioactive, and that they present a hazard, but that hazar
  10. If you want to know a little more about the history of radio-luminescence, lume and how lume works, this might be of interest. https://www.orau.org/PTP/collection/radioluminescent/radioluminescentinfo.htm
  11. The mechanism in the Indian watches may be genuine (although it is unlikely to have been services particularly well, if at all). The dials and hands on the other hand are a mixed bunch at best. Some are genuine, others repainted, and others still are fabricated from old dials. One or two I've seen, seem to be made from recycled soft drinks cans. By the way I have a number of Indian watches, and a particular soft spot for HMT watches which, if genuine, are Indian manufactured Citizen mechanisms. Good condition HMT watches are actually quite reliable and well made. Don't be surprised if
  12. Generally watches are "sealed units" in other words, the watch is designed to keep dust, dirt, moisture and so forth out of the watch. For this reason, anything inside the watch will stay in it, and anything outside the watch will stay out. Obviously if you open and service the watch there is the potential for radium dust to escape, but the quantities are miniscule. As various people have mentioned, unless you actually plan on eating the radium hands, then the risk of radiation damage from them is almost immeasurably small. Radium is not something to be messed with, but neither is it likely
  13. You just need to find someone who knows about making very small (and very basic) oscilloscopes. https://github.com/pingumacpenguin/STM32-O-Scope/wiki https://github.com/pingumacpenguin/STM32-O-Scope/wiki/Construction
  14. .. all that having been said, there is also the possibility that lack of lubrication may cause the impulse from the quartz oscillator and coil to have difficulty in running the stepper at the correct angle per step, and though this will generally cause it to go slow, it might just be possible for it to "micro-step" and jump in odd and interesting ways. I agree that it would be unlikely to run significantly fast due to mechanical issues, but lack of maintenance can make the rate erratic. My hunch is that it is the oscillator though, but unless you have access to an oscilloscope or a freque
  15. I know I'm being pedantic, but since a quartz crystal is an eletro-mechanical device, the two principal things that will affect its rate are electrical or mechanical. Generally crystals are both electrically and mechanically isolated from their surroundings as much as practically possible for this very reason. If you take an oscillating crystal and strike it sharply, and watch the results on an oscilloscope you will see what I mean. If the mechanical isolation of the tuning fork from the case has been compromised, then placing the crystals in different orientations will ca
  16. My guess is that since it is going fast rather than slow or stopping the quartz crystal is the most likely source of the issue. Dampness, physical damage or even just becoming loose in the casing will affect the rate of the crystal. If you are up for a bit of micro-soldering then you could try swapping the crystal. They are readily available on ebay and very inexpensive.
  17. Some of you might find this amusing.
  18. I've seen a couple of Metamecs with those Lumed hands, and a couple with the hands that mine has. None were exactly the same shape/model though. Does the book indicate what year(s) it is likely to be from? Don't encourage me. I get enough frequent flyer points from ebay as it is.
  19. Very nice. I missed out on a couple of Ferrantis and a very cool Smiths for the 404 collection. I'll keep trying though. I may even grab another Metamec, I'm enjoying fixing them. Just the right balance of mechanical fiddling and electrical peril to keep me amused. Speaking of fixing stuff, what with the virus restrictions and a need to keep the covid pot belly at bay, I've been walking a lot locally and enjoying the views, particlarly in the recent snow, and I was struck by the idea of getting some drone shots of the area. Now I know that any normal person would simply go out
  20. I picked up a couple of accessories for the microscopes. This was another bargain bin item from ebay. I'm pretty sure they are Russian (Lomo) and originally part of a larger set. The x8/23 is very sharp and clear and has a built in measuring graticule. The small plastic container has a second graticule, this one is a 15x15 square grid. This grid alone is worth twice what I paid for the whole lot, and the x8/23 goes for more than three times what I paid for everything. Second hand optical items are always a bit of a gamble, but these were all reasonably clea
  21. You could easily hide a small LED driver in the case. They are tiny, and would not look out of place in this Heath Robinson contraption. You could even hide it in its own Mechano or wooden box. https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=led+driver&_sacat=0&LH_TitleDesc=0&_sop=15&_osacat=0&_odkw=3v+transformer I assume the clock has some switched contacts, so you could use those to switch the low voltage output to drive a suitable LED bulb.
  22. Very nice. Notice that the mechanism looks very similar to the design of the Metamec, including an almost identical low friction bushing on the rotor. The coil is even larger, presumably using slightly coarser gauge wire, and is therefore probably even less efficient. The motor in these probably consumes something of the order of 2 to 10 watts, most of which is lost as heat. While this is not a hug amount in the grand scheme of things, it is many orders of magnitude greater than a quartz mechanism or even a transistorised coil oscillator one. Because the coils run warm, and because
  23. This Metamec design does look like something from the 1930s in the sense that it does not self start. I have heard that Metamec used designs and mechanisms from Smiths, so this may be based on one of their designs, and therefore may not have been cutting edge technology for the time. Most later designs use shaded pole synchronous motors, and typically only run in one direction, these older designs can be spun backwards which obviously leads to the hands tuning the wrong way (travelling backwards in time is always hazardous ). The modern designs also typically don't operate the motor c
  24. The earliest mine could be is around 1947, since that was when Metamec was founded, but it is more likely that it is from the early 1950s. I'd love to see a few pictures of the 1930s models. Who made them and do they work? Electric clocks have been around a lot longer even than the 1930s, but the first synchronous mains clocks date from around then. https://en.wikipedia.org/wiki/Electric_clock Many years ago (back in the early eighties) an Engineering firm customer of ours in Glasgow was closing down, and moving out of an old Victorian building. Bolted to the wall in their ha
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