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Joined 1 year ago
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Cake day: June 17th, 2023

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  • I don’t think I’d really view it as a typical first gen product; Kralyn has been working on it for quite a while and first showed it off 3 years ago. I saw a demo of LDO’s V3.2 at a RepRap Festival and it looks pretty solid.

    I haven’t watched the videos in quite a while but I’m sure there are demos of bed leveling, which would be my only real concern with unpacking and repacking it frequently.

    That said, since I haven’t owned one myself I can’t say “you should buy this!!1!”. Do you have the budget and time to start with another less-portable model at home to confirm you’re really into printing enough to spend the money on a positron? You don’t need a ton of space to store a Prusa MK4 when it’s not in use, and the robust frame plus fantastic bed probing mean there’s no calibration required after moving it.


  • If you think about bed adhesion, the forces on a light plastic part from gravity are negligible. Think of how much force it takes to pop a finished part off the bed compared to the weight of the part. When you have adhesion problems, I’m sure the plastic shrinkage is causing pretty large forces (or on a tall part the nozzle bumps the top of the print and has a long lever arm to pry the part off the build surface).



  • Are the test models ones that come with the printer, or models you’ve found online? If they’re from online, does the printer ship with any you could try? Something sliced by the manufacturer is most likely to work. If those fail, I’d contact customer support.

    I have no experience with resin, but is the resin coin stuck to the screen or the build plate? Are you angling the chess piece or trying to print it straight / vertical? My understanding is that resin prints need to be carefully aligned so they’ll peel of the screen, and big flat surfaces like the bottom of a chess piece won’t.


  • It’s because of the “lift to drag ratio”. Airplanes in level flight at ordinary speeds generate about 15x as much lift as drag meaning if the engine spends 1 unit of work moving the plan forward, the wings give 15 units of work* upwards. So flying level needs about 1/15th the engine power of going straight up. (I’m using “work” very sloppily here, not in a precise physics sense.)

    You can see this in sailboats too, which can travel faster than the wind when they’re sailing at an angle to the wind. Efficient boats travel faster when they’re going almost perpendicular to the wind, not straight downwind! This is because the “lift” of the sail pulling the boat forward even more strongly than the push of the wind in the downwind direction.

    While I can’t give an intuitive explanation for why this is, there’s a very easy demonstration that it’s true: kites. If a kite had a lift-to-drag ratio of 1, then it would fly at 45° up. It would fly 50 meters downwind of you when it’s 50 meters up. But any decent kite can fly at a much steeper angle than that; sometimes they look like they’re right over your head! That’s because with a lift to drag ratio of e.g. 10, the 1 unit of drag gives 10 units of lift; if it’s 10 meters downwind it will be 100 meters high.


  • If you want to tinker with the printer a lot, sure. If you want something that reliably Just Works, you’ll probably need to increase your budget. I’ve heard consistent stories from friends that their various Ender 3’s required lots of tinkering or upgrades to make them happy (one who found it so frustrating he gave up twice before finally getting it working ok, and this was with help from our “expert” friend who had lots of experience with Ender 3’s). And consistent stories from friends that their Prusa MK3’s Just Work and they don’t understand what the Ender 3 friends are talking about for how to solve various problems, because they just didn’t happen.

    My personal suspicion (owning neither) is that the QA on the Enders is probably not great, so some of them work pretty well and others are miserable. Any given user has no way to tell whether they are doing something wrong, or just got a machine with really poor tolerances. Ender 3’s are really common on support forums like this one, but I’m not sure how much comes from the low price leading to high sales volumes vs. users on average having more trouble getting jankier machines working well. But Ender clearly has many fans so…?