• 0 Posts
  • 12 Comments
Joined 1 year ago
cake
Cake day: June 15th, 2023

help-circle






  • It doesn’t help that, by the power of marketing, people can mean multiple distinctly different things when they say “bed leveling”.

    What you’re referring to is Z offset. This is the difference between where the endstop or probe triggers versus the actual Z coordinate of the nozzle. This is generally what you’re trying to set with the paper test. The paper test is only mostly accurate, though. A set of feeler gauges will do the same job with better accuracy.

    It can also mean tramming, which is making the bed itself planar to the printer’s gantry. This is what you’re doing when you adjust the ‘bed leveling’ screws on a printer or what happens automatically if you have triple lead ‘bed leveling.’ It pretty critical that Z offset is set correctly for autotramming. Manual tramming is essentially setting Z offset to be consistent at each of the bed adjustment points.

    Finally, mesh compensation also gets called bed leveling. Even if you have a perfectly trammed bed, the reality is that real, physical things (like beds) are never perfectly flat. Mesh compenstation probes multiple points along the bed, registers the difference between Z0 and the probed point, and builds a mesh that the printer uses to compensate for variations in the bed surface. The denser the mesh, the better the printer can compensate for small variations in surface flatness.

    All of these things are complementary and will have an impact on each other. The fact that they all get lumped into “bed leveling” causes a lot of confusion for folks when understanding what each is and does is pretty important to get the most out of a printer.


  • That’s inconsistent extrusion.

    As others have mentioned, the first thing I’d look at is thoroughly drying the filament. TPU is very hygroscopic and will become nearly unprintable within a couple of days of coming out of the dryer.

    Beyond that, you may be trying to run it faster than your hotend can melt it. TPU is pretty resistant to melt and cranking temp doesn’t help a whole lot. Actual flow can vary pretty wildly between brands depending on their exact blend but I’ve seen TPUs that refuse to flow more than around 2mm³/s through a standard 0.4 nozzle. (Volumetric flow is roughly layer height * width * linear speed).


  • A 2.4 will be better than an Ender 3, but there are better options out there. The flying gantry is a solution in search of a problem, the gantry is heavy and not particularly rigid, Voron toolheads don’t cool particularly well, the rigid bed mounting is a recipe for bed taco, etc.

    Which isn’t to say that V2s are bad printers – they can turn out great prints. But if you’re starting fresh today, I’d seriously consider any number of printers over it.

    If you want to stay within the Voron ecosystem for whatever reason, the Trident’s a better design. It still lacks things like kinematic bed mounting that are standard fair on other designs today, though. I’d stay away from Tap on any of them – I’m still baffled that thing gets promoted as being a good idea.

    In terms of bang for your buck, it’s incredibly difficult to beat the VzBot kits. It’ll be a less expensive and more capable machine than a V2.4. There are panels available to enclose it. I don’t love the Z stage on it, but I can overlook it given the value the rest of the printer gets you.

    The Annex K3 is an absolutely killer little machine, but is only 180x180 build volume. The small build volume is free rigidity, though, and K3s can be made true high temp capable with less relative effort than a lot of printers. I’m not as big a fan of the larger Annex printers (K1/K2), personally.

    The Rat Rig v-Core was probably the best value CoreXY before the VzBot kits came around. Enclosing them is more of a challenge due to all the PETG parts, though. The EVA toolhead provides a ton of flexibility for mixing and matching parts, if that’s your thing.

    In terms of take it out of the box and print, nothing beats the Bambu X1 and P1P. They’re great units. They’re a closed ecosystem though, and not modification friendly if that’s what you want.

    My main workhorse printer’s a Railcore II. Great machine, but the design’s aging and I generally wouldn’t recommend a new build today outside of a few very specific applications. It was cutting edge when the design was released in 2018, but, as with the 2.4, the wider community has learned a lot since then about fundamental printer design and there are better options now.


  • Restricts Freedom to Use the Software

    I’ve always found this particular one somewhat frustrating. It’s essentially the intolerance paradox repackaged into a software licensing analog:

    “You are restricting the freedom of users by taking away their ability to close the code and restrict the freedom of other users!”

    It’s always read very “I got mine” to me.

    That said, while I lean copyleft, I also don’t find just barring commercial use entirely interesting. The goal is to ensure source code remains available to users; I think there are better ways of addressing that than trying to delineate and exclude commercial use.



  • @galaxi

    @zipsglacier

    Drying is part of the process when raw plastic pellets are used in injection molding. The only reason it’s not more common in 3DP is that common materials like PLA and ABS arent particularly hygroscopic. PETG is slightly more hygroscopic, but materials like TPU, PET, nylons, etc are highly hygroscopic and definitely need drying to print well.

    Also remember that PETG needs more room between the nozzle and the build plate (higher z offset) so that the filament doesn’t stick to the nozzle and make a mess

    This is one of those pieces of 3DP lore that isn’t correct. If Z offset is set accurately, it doesn’t need to be changed for any material, but extrusion multiplier/flow does.

    The reason why bumping z offset bandaids the problem is because PETs are highly incompressible, i.e., they don’t respond well to being squeezed and will displace under pressure. Raising the z offset means you’re putting the same amount of material into a larger physical volume. This effectively lowers EM for the first layer, but introduces accuracy issues in the rest of the print.

    Instead, it’s better to make sure z offset is dead on accurate and then adjust EM down so that flow is correct throughout the print.