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cosmology

Dormant
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  1. Makerbot My printer which cost 5,227 usd True.. Good point, I forgot about the new Gen of makerbot. I had written them off after the smart extruder fiasco. Is it reliable? Does it use the same very inexpensive motion components as, apparently, all other inexpensive machines use?
  2. Uhm Yes.. I dont have a deep set hatred for 'cheap 3D printers' - I just have watched the market develop into a utter crapfest of lowest common denominator behavior, typified by patenting open source ideas, providing subpar equipment, breaking cardinal rules of open source by creating forks only for branding purposes, and so on. After I ranted above, I did think about the fact UM releases ALL of their materials open source, even for their flagship products. Of course, they have to in most cases, given the licenses of the projects they use. But they do a good version of commercializing open source. I agree. My real frustration is thus: having been asked by the lab leader to get a 3d printer to make spectrometer component enclosures and mounts, I sighed deeply knowing what was going to happen, all my time would now be spent justifying the inability of a cheap ass 3D printer to make parts. So I convince them to get a UM2 even though it is fairly expensive compared to what they wanted to get based on another lab's "positive" experience with cheap 3d printers. Sigh. I knew what was about to happen though, having been around and used lots of hobby 3d printers. So we got the UM2 - immediately the Z axis is grinding. So we try it out, it prints ok sometimes, other times appears to be under extruding, except the grinding sound and shuddering z table give away the real issue. The silver fillament we have seems to be somewhat odd, so we try our white stuff, big improvement - except the table is now shuttering and grinding in the downward direction. The rest is history - it is the plight of the owner of a $400 microcenter machine, or a $200 self built machine... Cheap linear motion components and reliability issues. "This is normal for 3d printers", some say - having a now misplaced pioneering spirit influenced by the early rep rap experience and ethos. It is normal for r&d to go through these troubles, which is what rep rap was doing, iterative self determined improvements and tinkering.. Flash forward 14 full years, and we have proliferation of 3d printer makers - all of them using the same style of low-end parts as the original rep-rap users were using to keep costs of their experimentation down. I know it is normal for a product to retail for roughly 10x the mfg cost. This is normal, and necessary for a company to survive. But using parts that are not up to the task just because 'it is normal to struggle with these machines' is sad. Maybe I got a bunk bearing by accident.. I suppose it is possible. But the quality of the components belies the real purpose these bearings were manufactured for: non-precision motion in things like food packaging equipment destined for the domestic chinese market. Ive digressed a lot. Sorry. I will try to get the reseller to send us replacement bearings and rails. If they cannot or will not, we may purchase appropraite components from sources known for quality. This will cost some $100 or more, and take half a day of my time. Lovely. "Just send it back" some will say - but we already have invested X time into this. Sending it back for a new machine is a possibility, perhaps, but repackaging and sending back a machine, receiving a new one, and so on... Time consuming. Sorry for being so ornery. I was just deeply disappointed, like a kid fully realizing his x-ray specs will never see through anything, and barely work as a demonstration of diffraction.
  3. UM2 = $2500. It contains roughly $300 of materials and parts. First off, 1) The entire 3D printing market DOES border on a scam - most of the companies involved STOLE open source projects and contribute nothing back to them at all. Meanwhile "3d printers dont just work" is a foolish mantra. What printer costs a lot more than $2500 UM2 without going into the $25-$50K range? Is there any? UM2 was supposed to be the one that 'actually works' The failing Z bearings in my UM2 likely cost less than $4 each.... I am sitting here considering replacing them with the cheapest legit linear bearings which cost around $25/each from McMaster Carr. These will be 'real' linear bearings, that come in an actual SKF package. These 3D printers all relied on brilliant people's work - and they contribute back with tepid self-branded modifications of the slicers and hosts. 2)
  4. There are two ways to ship a product: 1) With easily identified quality control issues 2) Working The bearings are not 'simply making a sound'. I spend all day designing equipment and tools - I know what linear motion components are like at different price points. Our machine came with obvious rejects.. They literally seize up completely when changing direction, they make grinding sounds, their finish looks suspect at best. A 3D printer that comes with $4 linear bearings, that are failing new.... That is not what I expect for $2500. And yes, the cost absolutely does matter.
  5. If it has the same problem our UM2 has (almost new machine) - the Z axis bearings bind\stick - the grinding sound would be the motor struggling and failing to step.
  6. This isnt a remotely unique problem - it appears to basically be a common experience for UM2 owners... Poor saps that we are.. Expecting the massive increase in cost to have better quality was foolish... Deep down I knew this would happen, of course... The entire 'consumer' 3D printer market borders on a scam... Bulk purchasing QC-failed chinese parts and then rebranding open source hardware is.... One way to try and make a buck, I guess...
  7. Hello! Recently when faced with buying a 3D printer for the busy astrophysics lab I work in, I recommended a UM2 because they are supposed to 'just work'. Our printer arrived making weird grinding sounds when the table moved downward, but not upward. After some good and some bad prints, the table began violently shuddering on downward motions, and print quality became terrible. I spend hours carefully taking the machine apart, put the bearings into an ultrasonic cleaner, and still the machine makes grinding sounds. It has always made grinding sounds, it has always had layer issues. Why is a $2500 machine relying on the absolute cheapest chinese parts available? The rails and bearing look like they were polished by dragging behind a car.. Why do I now have to spend another half day of our projects budget on trying to fix a $2500 machine that has like 75 hours of use on it? Why didnt quality control stop this machine from being shipped? The problem happens on every print - you can hear it grinding... Why was this allowed to happen? I am afraid i will not be able to recommend Ultimaker products to anyone, nor is our lab able to use the machine we bought. I dont have time to do this.. We spent the $ to avoid this... And for what? To have to go through a distributor who then tells us to contact ultimaker? Sigh.
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