Large Mid-Century Starburst Clock (400mm/16")

prusaprinters

<p><strong>Style</strong></p><p>A large starburst wall clock in the Atomic-Era Mid Century style.&nbsp;</p><p>In gold it also looks like it would be at home in a Catholic church or Masonic temple!</p><p>I used a Silk Gold PLA. Copper or Bronze are also appropriate mid-century starburst clock colours. A black &amp; white chequerboard arrangement of the quarters might be interesting too.</p><p><strong>9 builds</strong></p><p>The clock quarters are sized to be printed one at a time on an i3-sized printer. Sorry Mini-users, this will not work for you. It cannot simply be scaled down in the slicer as then the mechanism would not fit. The builds are:</p><p>4 front quarters - I sliced mine at 0.15mm Quality setting, which was probably overkill for something hung on a wall and not handled or used very close-up. Roughly 4 hours per build at this quality level, so you could save some time by turning it down a notch. Support is required to stop sagging that would cause fit problems. Use auto setting.&nbsp;</p><p>4 rear quarters - I sliced at 0.3mm draft quality. Support should also be used - not much is added on auto setting. Roughly 2 hours per build.</p><p>1 set of 1 joining ring and 12 small slotted pins - I sliced at 0.3mm draft quality. Support is not required. Less than ½ hour build. The small rings should be printed with the big ring rather than with the quarters to avoid the tool path leaving a quarter, inevitably resulting in an undesirable witness mark.</p><p>Take care when popping the quarters off the build plate - slide a credit card in from the separated side to pry a stuck spoke tip off rather than just trying to bend it off or the tip could be damaged.</p><p><strong>Print Assembly</strong></p><p>Note - the assembly photos uploaded are organised in an order that corresponds with these instructions.</p><p>Start by placing one of the little tip-joining slotted pins on a hard surface, and push a Front Quarter spoke tip down hard onto it. It will go half-way in and stop. Make sure it is seated flat, not at an angle. See photos. Repeat 12 times. Do not randomly fit them to Front AND Rear quarters or you will end up with two on one spoke tip and none in another spoke tip.&nbsp;</p><p>Lay out the 4 rear quarters and use <strong>5-minute epoxy</strong> to glue the large ring into its seat. - see photos. There is no need to put glue between the abutting faces of the quarters - that would make a mess - the purpose of the ring is to join them without having to do that. Avoid getting glue on the upper half of the ring at this time.</p><p>Wait till the back assembly has hardened and can be handled before starting the next step.</p><p>To attach the front quarters to the back assembly, use epoxy resin again, but i<strong>f using 5-minute epoxy do not attempt to do more than one quarter at a time</strong> because the glue will have hardened before you have got them into place. Actually, while it is very handy to assemble the rear side with 5-minute epoxy as it gives you something solid to handle quickly, for fitting the front side I suggest you use <strong>24 hour epoxy</strong>, as this will ensure you are able to align everything and tape it tightly together before it has started hardening. Apply glue to the rear assembly and place the front quarters onto it: the centreline rib down each spoke is specifically provided for applying glue to - it allows you to be a bit messy without any risk of it oozing out of the sides. Work from the centre outwards, and stop applying glue 20mm from the end of the tip where it is now very narrow, so that glue does not ooze out of the sides. Also apply glue to the top and outer face of the ring - try to avoid getting any on its inner face.</p><p>Squeeze the spoke tips together - hopefully they will all friction-fit tightly. A couple of them didn't quite do it on my clock but I preferred to leave them with a small gap than risk making a mess trying to bond them.</p><p>Use masking tape on every spoke to ensure everything bonds tightly and unexpected gaps don't open up - see photos. You may run a <strong>small </strong>amount of glue down the quarter joining lines on the inside of the clock only at this point.</p><p>Then turn the clock face-up, and leave it overnight until the glue sets. I used a small flat-bottomed bottle to add a bit of weight to ensure the joints stayed closed. It does not have to be teriyaki marinade, but it is very good! The gluing was perfect the following morning.</p><p><strong>Buying the Mechanism &amp; Hands</strong></p><p>I got the mechanism and hands from eBay - see screengrab - I cannot include the URL as it is flagged as spam content. If that seller is not suitable for where you live, check the uploaded mechanism drawing to make sure you buy one of the correct size and shaft length. They are readily available and quite cheap. Do yourself a favour and get a silent mechanism. Nobody likes a loudly ticking clock.</p><p>There is a commonly available style of hands that are the perfect shape for this clock. See photo. The set was described as 86mm size - that is measured from the tip of the hour hand to the axis of rotation. &nbsp;They are also available in gold which would be even more perfect than the ones in the photo - I have them on order but only have the silver ones for the time being. If you don't use this style of hand then unless you have made an even better design of your own, I would judge that you have spoiled your clock - please make the effort to get the appropriate hands.&nbsp;</p><p>(It is a bizarre quirk of some original mid-century starburst clocks that occasionally they have fabulous atomic bodies paired with grossly inappropriate Roman numerals and twiddly neo-gothic hands - I can only imagine there was a massive argument between the designer and the finance department, the designer lost and the clock got stuck with random parts that happened to be in stock rather than ones that complimented its body. You do not need to perpetuate this travesty!)</p><p><strong>Mechanism Assembly</strong></p><p>This bit is simple - insert from the back with a rubber washer between the mechanism and inside of the print if one is supplied. Then from the front, place the metal washer over the protruding shaft and do up the nut - finger-tight only, no tools. Then fit the hands, all pointing to 12 (check where 12 is by the hanging loop on the mechanism). Then fit the battery and use the adjustment wheel to set the time. Do not try to set the correct time as you fit the hands or by trying to turn the hands with your fingers.</p><p>Now bang a nail into the wall, hang your clock and everyone will admire it and agree that your printer was well worth the money!</p>