Last year, mathematician and professional optical illusionist [Kokichi Sugihara] came up with an arrow that only points one way. Technically, it’s ‘anomalous mirror symmetry’, but if you print this arrow and look at it juuuussst right, it appears this arrow only points one way. [Ali] had the idea to turn this arrow illusion into something motorized, and for that he turned to 3D printing. The models for the illusion arrows were already available, but there…
Rich Whitehouse is a video game preservationist and a veteran programmer in the video game industry. This story was originally published on Whitehouse’s website. Yesterday, Google announced Stadia, a video game streaming and development platform that leverages the tech giant’s data centers around the world to let users play high-end video games on practically any screen, with no need for a console or PC. We still don’t know what Stadia will cost users, what games…
We’re into the final days before members of the European Parliament vote on the Copyright and the Digital Single Market Directive, home of the censoring Article 13, and the anti-news Article 11. Europeans are still urging their MEPs to vote down these articles (if you haven’t already, call now, and stepping up the visibility of their complaints in this final week. Take Action Stop Article 13 The first salvo drawing attention to the damage the…
Six Vermont representatives have introduced HB 444. It provides for ranked choice voting for all non-presidential primaries, and also in general elections for Congress. Thanks to Mike Drucker for this news. … Continue reading →
It’s been a few years since my reprap’s journey began, and I think it has reached the conclusion, before a total overhaul and replacement of the frame (3.0?).
I replaced the 45° rear frame brackets with slightly better ones (used a bit off-label — I’m just bolting the frame part to a table) that mount to where I had originally intended the supports to go, decided to see if the hype was real and swapped my worn out three year old belts for real, live Gates GT2 belts, replaced the original y-axis mounts that made it impossible to remove the y-axis without getting under the printer with metal brackets that are accessible from the top, and swapped the y-axis parts for the Wilson II y-axis.
This resulted in some slight improvements in print quality (mainly in y, since the original belt was really worn out and there was a ton of backlash… not helped by my super misaligned belt line), but nothing major. Worth the effort if only for the y-axis not being awkwardly mounted and impossible to remove, and the control board being in a better position.
At this point it’s clear that the 2020 frame is too flimsy for a printer of this size… as such, I’m planning to design a new frame inspired by the Prusa i3 MK3 Bear Frame Rebuild, but in openscad instead of a proprietary cad program that doesn’t run on GNU/Linux (still debating continuing hacking on the pre-MK2 community version of the Prusa i3 or just re-forking the mainline Prusa i3 MK3).
Original frame braces for the TS … I sized the rear extrusions for mounting to the top of the frame but never go around to making my own mounts so the extrusions went way past the edge of the table…
Replaced the idler-side frame brace. Not messing with the brace the control board is mounted to until rebuilding the y-axis.
cat tax
new y-ends! In addition to having adjustable tension without adding backlash like the old tensioner did, they give me ~6mm more z height.
Just before the overhaul
y-axis mounts from hell
you can’t get a screwdriver into either of these except from below the machine which makes working on the y-axis a major pain, especially since my frame has to be bolted to a table for rigidity.
After much struggle, these replaced the y-axis brackets. The attachment to the xz frame uses ball spring t-nuts so they stay in place when removing the brackets for easy alignment on re-assembly. These also feel way stiffer than the plastic mounts (and the screws can be checked/tightened regularly).
Was a bit messy under the printer after getting the y-axis off.
All clean now. And the plastic corner brackets I couldn’t get out (without much suffering) before have been replaced with metal brackets, matching the top of the frame (I had to learn the hard way how much stiffer the metal brackets are)
What have I gotten myself into?
Y-axis back together, with the fancy GT2 belt (and original 10mm hardware from the TS, not taking the entire print bed apart this time…)
All together again. Much nicer looking I think! Still needs some cable management redone (not that it was ever done very nicely before)
Back and ready for action.
A quick and probably meaningless rough history of changes to the machine, that I want to expand into a page on my actual website eventually (more naval gazing?):
1.0: Straight Wilson TS, with a 300x400x300 mm frame, an itty bitty double flex extruder, and 10mm linear rods for the y-axis.
1.1: Swapped the threaded rod for a lead screw on the z axis
2.0: Upgraded the linear rods on the x and z axes from 8mm to 10mm
2.1: Upgraded to a Panucatt Azteeg X5 GT running Smoothieware (great hardware, adequate firmware).
2.2: Fixed bug in z-axis that was causing the motor mount to shift 2mm vs the x-axis parts (perils of using two different source trees for different parts)
2.3: Swapped the y-axis for the Wilson II y-axis, replaced the rear frame braces.
DURHAM, N.C.—The Durham-Orange Light Rail Transit project, or DOLRT, is a planned 17.7-mile line linking Durham and Chapel Hill, North Carolina. The plan is two decades in the making—born of an ambitious 1990s scheme to stitch the state’s booming Research Triangle region together via rail.Since then, DOLRT has consumed more than $130 million in public money. In 2011 and 2012, voters in Durham and Orange counties approved half-cent sales taxes to fund transportation improvements, including…
Democrats and progressive groups across the state of New York are pushing back hard against an effort to ban fusion voting, a system that allows multiple parties to nominate the same candidate. The assault, according to those on the receiving end, is being driven by Gov. Andrew Cuomo’s ongoing hostility toward the Working Families Party, which has been a primary beneficiary of fusion voting in the state. A majority of Democrats in the state Senate,…
Introduction When I first got involved in managing a Postgres database, I was quickly introduced to the need for replication. My first project was to get our databases up on Slony, which was the hot new replication technology, replacing our clunky DRBD setup and allowing near-realtime read-only copies of the database. Of course, with time and scale, Slony had a hard time keeping up with the write traffic, especially since it ultimately suffered from write…
Following months of protests from its employees, Google announced last summer that it would not renew its contract with the military on Project Maven, an initiative to use artificial intelligence to improve the targeting and surveillance capabilities of drones on the battlefield. In an email sent this week by Kent Walker, Google’s senior vice president for global affairs, the Silicon Valley giant appeared to hedge on its commitment to fully cut ties with the drone initiative. In an…
Earlier this month, security researcher Victor Gevers found and disclosed an exposed database live-tracking the locations of about 2.6 million residents of Xinjiang, China, offering a window into what a digital surveillance state looks like in the 21st century. Xinjiang is China’s largest province, and home to China’s Uighurs, a Turkic minority group. Here, the Chinese government has implemented a testbed police state where an estimated 1 million individuals from these minority groups have been…
For our latest “Voices & Choices” podcast, Lawrence Lessig and Adam Eichen of Equal Citizens sat down with Nancy Lavin, FairVote staff writer, to talk about their efforts to bring ranked choice voting to New Hampshire’s presidential primaries: how it works and why it matters. The pair also share the origins of their interest in electoral reform, and Lessig looks back on his own presidential run in 2016. The following is an excerpt from that…
When activists in New York get together to send letters to their elected officials, they pool together money to pay for postcards, stamps, and even pizza to chow on as they do their work. Printing out flyers to advertise their events can also cost a pretty penny. These efforts are almost always volunteer-funded, but if Gov. Andrew Cuomo gets his way, activist organizations will have to register as lobbyists if they spend $500 a year on…
After months of investigations and media reports into possible absentee-ballot fraud, we finally have a decision in the disputed election in the North Carolina 9th Congressional District: There will be a new election. This will be the first time that a congressional election has been redone since 1975. On Thursday, the North Carolina State Board of Elections voted 5-0 to hold a do-over election after hearing evidence that an illegal absentee-ballot scheme cast doubt on…
Law enforcement agencies love their automatic license plate readers. ALPRs do what cops physically can’t: scan millions of plates a year and run them against a number of shared databases. The systems are black boxes. The public is often given little information about how many plate images databases store or for how long. Law enforcement agencies rarely audit the data, providing zero insight on the number of false positives ALPRs return. Non-hit photos are sometimes…
Beware of Using Young People’s Blood to Halt Aging:”There is no proven clinical benefit of infusion of plasma from young donors to cure, mitigate, treat or prevent these conditions, and there are risks associated with the use of any plasma product,” the FDA said in a statement from Commissioner Scott Gottlieb and Peter Marks, head of the agency’s biologics center.The idea of infusing young blood to fight aging has attracted technology entrepreneurs like billionaire Peter…
Bernie Sanders is running for president again. His message is simple: there’s a class war raging and working people need to win it. Bernie Sanders speaking at an event in Phoenix, Arizona on July 18, 2015. Gage Skidmore / Wikimedia It’s finally happening. Bernie Sanders just announced that he’ll be running for president again. Judging from its early entrants, the politics of this upcoming Democratic presidential primary will be the most progressive in decades. All…
San Francisco’s iconic Anchor Brewing Company is now the scene of a unionization fight. We spoke with Brace Belden, one of the organizers. Yumi Kimura / Flickr Anchor Brewing Company is often called the first craft brewery in America. It operates the largest factory in San Francisco, and the company has deep historical roots in the City by the Bay. But then, so does the International Longshore and Warehouse Union (ILWU). Last week, workers at…
President Donald Trump admits he’s making his move because he didn’t get his way with Congress, and in the process, he hurts American communities. After more than a month of threats, a government shutdown, and bipartisan action by Congress, President Trump has finally declared a national emergency to spend billions of taxpayer dollars on his border wall obsession. In response, the ACLU will file a lawsuit early next week challenging this blatantly illegal executive action.…
Charter schools are like tree roots growing into cracks in the building of public education. If not stopped, they will bring it crashing down. Teacher’s strikes are weakening the political support that charter schools have obtained in the plutocratist system.
