I have also found even though I use it a lot, that Blender is a better character modelling tool than CAD tool. I know there has been work done in this area and improvements made, but be careful about numerical manipulations. In particular I have seen rounding issues where vertices positions change slightly.
Are you able to print a 120mm circle that comes out at 120mm before post cure?
Obviously Blender is not an engineering CAD tool. It’s just the only tool that I found that will do this type of deformation. Unfortunately their numerical inputs are vague at best.
I do like the idea of a Gcode transposer.
I’m measuring geometry without post cure. Shrinkage is a uniform scale that can be applied any time and would only confuse things at this stage.
My expectations are that I can make dimentionally accurate prototypes for injection mold parts for my clients just like we have been doing with outside services to this point. The Form labs printer does a fine job. This one can be out almost 2 mm on larger objects.
I think if this got out, peopoly wouldn’t be selling so many units and might actually finish the software for their machine.
I will eventually want to print dimensionally accurate parts so I’m quite interested in the topic. I will look at some GCODE to see what paradigms are used in the Moai profile for Cura.
Have you looked at the GCODE in Reptier Host by chance?
I would love to know the results of your concentric ring tests.
What tolerance can the Form Labs hold?
Personally I don’t need that print size, but I know of people here having the same issue. I haven’t tried with firmware 1.16 though that is supposed to fix exactly that kind of aberration. Unfortunately I’m fighting with over issues that are actually affecting my work
@peopoly Does the printer’s coordinate system zero at the center of the bed or on one of the corners?
You can edit the P_yuan-test gcode file by hand and see where the laser goes.
zero is not in the center (it’s bottom/left in the coordinate system)
…but the galvos are centered on the build plate correct? At the very least there is likely an intensity difference across the plate due to variable path length with fixed lenses. There is also spherical positional distortion i.e. one degree of mirror rotation may yield 1mm of linear travel at the center and 2mm (made up numbers) at the edge. None of this is rocket science though…
which is compensated by the software. even camera lenses distortion is often corrected in post production. How good or how bad the algorithm is I’m not sure.
zero in gcode starts at the bottom left corner as @matt3o said.
What do you mean by “post production”? How the control board interprets and acts on the gcode?
When the laser path length changes the spot defocuses spreading the energy over a larger area. The controller could move the location of the spot to correct position of the “edge” of the cured resin. I don’t know enough about the photopolymer chemistry to say if the lower energy density (but same total energy) affects cure time. If so, the controller may also slow the travel down or turn power up.
One could argue that the Moai SHOULD do all of this under the hood and that a user should not have to care about how it happens. The proof is in the results though. Has anyone done a systematic evaluation of dimensional accuracy across the build plate?
Here is a library that could be easily modded to scale the gcode. It is also compatible with Cura.
Has this really not been solved yet??. I really need the dimensional accuracy. Parts near the edge of the build volume are about 1mm off. If it was 0.1mm off it wouldn’t be a big deal but 1mm is too much for me. Even if someone has a solution that makes it even slightly more precise please let me know as i wont be able to continue with my project till this is solved.
Please let me know if there is any improvement at all. Thank you
…unfortunately, the problem of distortion (high inaccuracy in the four corners of the print area) in the Moai 130 and 200 are still not solved.
Obviously, accuracy does not seem to be a high priority for PeoPoly.
I have provided Peopoly with my measurement data (Moai 200) for correction in Asura 2.2.3. However, to my knowledge, no information about that has been published so far.
That´s bad news, I´ve been following these threads for a long time, I´m starting to work with projects that require more accuracy and the corner´s distortion is starting to make it impractical to do some projects with Moai.
Damn this is a bummer.
This level of distortion rules this machine out for my application…And here I thought I was all done researching
I guess we can safely assume that this is why the work volume on higher end home units are so much smaller.
I dont care about massive work volumes, I care about having an accurate, repeatable, USEABLE work volume.
Looks like MSTL is back on the menu…
Have you tried the new Moai 200 calibration @ad_fontec
That is based on your scanned data
The Moai 130, many users have reported quite high tolerance under 0.02mm using the current Asura method (with customization) There are reports here and in the facebook about it. Have you test it yourselfs?
meine Antwort siehe bitte hier:
Mein Angebot für eine konstruktive Zusammenarbeit steht noch.