{"id":130,"date":"2014-07-19T22:18:15","date_gmt":"2014-07-19T22:18:15","guid":{"rendered":"http:\/\/3d.rayharwood.com\/?p=130"},"modified":"2014-07-19T22:18:15","modified_gmt":"2014-07-19T22:18:15","slug":"i-built-a-bridge","status":"publish","type":"post","link":"https:\/\/3d.rayharwood.com\/?p=130","title":{"rendered":"I built a bridge!"},"content":{"rendered":"

Usually when you design a 3D-printed part, you want it to “build from the ground up”. After all, having the extruder “hang filament in mid-air” seems like a pretty difficult request. But today, I did it.<\/p>\n

<\/p>\n

For one of the Coins-Worth pieces, I needed to add a structural piece so that one of the in-place servos could reach it. This piece normally sits in Coins-Worth rotated 180 degrees, and catches the coin so that it can be photographed. The servo already in place activates a small rod that rapidly flips the coin, and I’ve reserved a little bit of the reverse travel of the servo to lift the coin-catch enough to allow the coin to slip through.

\"FreeCAD<\/a>

FreeCAD view of part with bridge added (in red)<\/p><\/div><\/p>\n

But how to get to the servo from the “feet” on the bottom of the plate? I had never created a bridge before. A bridge is essentially filament extruded in mid-air, not actually resting on anything other than supports on either end of the bridge.<\/p>\n

Basically I dropped in a FreeCAD box, modified it into the appropriate dimensions (1 mm thick, 32 mm wide, and 10 mm long), and moved it into position with a 25 degree slant. (I may need to modify the position slightly to fine-tune the servo’s strike point.) The bottom edge of the new piece (bottom as it is printed, anyway; the top as it sits in Coins-Worth) doesn’t have anything to hang onto other than the two sides.<\/p>\n

Watching it print for the first time was kind of nerve racking, waiting for the first layer where the bridge started to be printed. But then it happened… and it worked beautifully!

\"Actual<\/a>

Actual photograph of the printed part.<\/p><\/div><\/p>\n

One or two of the layer strands on the bottom of the bridge are not fully adhered to; you could pull these strands off. However, they provide just enough support for the remaining layers, which are fully adhered. <\/p>\n

You’ll note there’s a little cut-out in the middle of the part on the top edge. This is to accommodate the flipping pin and servo clearance for actuating it. It’ll be clearer once I’ve got the whole device assembled, I promise!<\/p>\n

At least I know I can build a bridge where I need one.<\/p>\n","protected":false},"excerpt":{"rendered":"

Usually when you design a 3D-printed part, you want it to “build from the ground up”. After all, having the extruder “hang filament in mid-air” seems like a pretty difficult request. But today, I did it.<\/p>\n","protected":false},"author":1,"featured_media":131,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[7,6],"tags":[21,18,22],"jetpack_featured_media_url":"https:\/\/i2.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2014\/07\/FreeCAD-Bridge.jpg?fit=922%2C496&ssl=1","jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p76pQa-26","jetpack-related-posts":[{"id":94,"url":"https:\/\/3d.rayharwood.com\/?p=94","url_meta":{"origin":130,"position":0},"title":"Coins-Worth is coming together!","date":"July 10, 2014","format":false,"excerpt":"The current iteration of the Coins-Worth device version 2 is now about 50% together. Here's a sneak peak at the end of week iteration 7\/3\/14. Taken from above, there are two tall walls that support the smaller functional components.\u00a0\u00a0I refer to the\u00a0left half of this piece as the \"stacking station\",\u2026","rel":"","context":"In "3D Objects"","img":{"alt_text":"","src":"https:\/\/i1.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2014\/07\/20140709-182946-66586377.jpg?fit=1024%2C768&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":140,"url":"https:\/\/3d.rayharwood.com\/?p=140","url_meta":{"origin":130,"position":1},"title":"Coins-Worth Update 7\/18","date":"July 20, 2014","format":false,"excerpt":"Coins-Worth prototype Version 2 is coming along nicely. \"What's the hold-up?\", you might ask. Since I'm new to manufacturing and 3D printing, I'm having to do a lot of trial-and-error in creating the parts design. This isn't a bad thing, since it drives me down a number of learning curves\u2026","rel":"","context":"In "Coins-Worth"","img":{"alt_text":"","src":"https:\/\/i0.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2014\/07\/20140720-120226-43346368.jpg?fit=1024%2C1024&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":199,"url":"https:\/\/3d.rayharwood.com\/?p=199","url_meta":{"origin":130,"position":2},"title":"Coins-Worth assembly","date":"October 10, 2014","format":false,"excerpt":"Just before moving around Labor Day, I had assembled a Coins-Worth unit with as much as I had.\u00a0 This picture shows the side view, with the power and USB connectors on the lower left, the Logitech web camera on the upper right, and the feeder tube on the upper left.\u2026","rel":"","context":"In "Coins-Worth"","img":{"alt_text":"","src":"https:\/\/i2.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2014\/10\/20140725_180556563_iOS.jpg?fit=900%2C1200&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":6,"url":"https:\/\/3d.rayharwood.com\/?p=6","url_meta":{"origin":130,"position":3},"title":"I'm printing 3D!","date":"June 29, 2014","format":false,"excerpt":"Retired at 60 and sitting on my butt? I don't think so! As I tell people, \"I'm busier than I ever was \u2013 and I'm enjoying myself more than ever!\" One of the things I'm doing is creating a coin processing device called Coins-Worth.\u00a0 But to do this, I needed\u2026","rel":"","context":"In "General"","img":{"alt_text":"","src":"https:\/\/i1.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2014\/06\/20140629-100905-36545551.jpg?fit=1024%2C768&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":285,"url":"https:\/\/3d.rayharwood.com\/?p=285","url_meta":{"origin":130,"position":4},"title":"Made a Wood Shop Accessory: Shop Vac to Sander Adapter","date":"June 17, 2015","format":false,"excerpt":"Sometimes it really does come down to \"necessity is the mother of invention\", and 3D printers make this possible for nearly anyone willing to invest a little time. Today, I did it again - from design, print, and ready in under 2 hours! Note that you can click on each\u2026","rel":"","context":"In "3D Objects"","img":{"alt_text":"","src":"https:\/\/i0.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2015\/06\/20150617_151128785_iOS.jpg?fit=1200%2C900&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":358,"url":"https:\/\/3d.rayharwood.com\/?p=358","url_meta":{"origin":130,"position":5},"title":"Tabletop Frame Holder","date":"November 6, 2015","format":false,"excerpt":"Concept: My wife and her mother are working on a project to put 5 x 7 inch\u00a0pictures in a wooden frame, and they thought it would be a nice touch to have a frame holder to display the picture on the tabletop.\u00a0 My thought, of course, was to 3D print\u2026","rel":"","context":"In "Frame Holder"","img":{"alt_text":"","src":"https:\/\/i2.wp.com\/3d.rayharwood.com\/wp-content\/uploads\/2015\/11\/FrameHolder2.gif?fit=905%2C343&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/posts\/130"}],"collection":[{"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=130"}],"version-history":[{"count":5,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/posts\/130\/revisions"}],"predecessor-version":[{"id":138,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/posts\/130\/revisions\/138"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=\/wp\/v2\/media\/131"}],"wp:attachment":[{"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=130"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=130"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/3d.rayharwood.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=130"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}