XY resolution for large WSF printer

Discussion in 'General Discussion' started by rusalkin, Feb 17, 2013.

  1. rusalkin
    rusalkin New Member
    It says in the material page that the powder layer is roughly 0.12mm stepping (Z) but what are the dimensions on a minimum XY dot ?

    I assume because it is a laser it can theoretically be infinitely small, but in reality lets imagine we have just one layer of powder what is the smallest "dot" we can create ?

    I assume it will be round, if so what is the distance between two of these dots where some form of fusion between the two will occur, and what is the distance between these two dots where they would no longer be even slightly fused ?

    Is there an accuracy margin for XY ? ( i know it says 0.15mm, but i assume its for 3d objects, to account for stepping etc...)

    Would the same properties propagate if we add layers but not move the dot, as in just building up a straight line (cylinder) into Z ?
    I know it would instantly break once the powder is removed, but still...
    TOM_TOM_TOM Well-Known Member
    Has anyone found the answer to this question?
    What's the resolution of the laser in millimeters?

    I want to make the shaft for bearings just 1 step tighter, but I don't know how much more to reduce the diameter of the shaft. Ideally I want to just shrink it by 0.05mm, but I don't know whether the laser controller would actually pick up this change.
    Last edited: Jul 5, 2013
  3. mkroeker
    mkroeker Well-Known Member
    Interestingly i do not even find this information on the EOS website - probably the absolute minimum depends on too
    many outside factors such as calibration, material grade, humidity, or even vibration damping.
    In the context of Shapeways, the paramount issue will probably be print orientation, which as you know you currently
    do not have control over. (Unless your model falls in an easily recognized, relatively high volume category where the
    SW engineers know that they have to use a specific orientation to get it to print without ugly stepping artefacts)
  4. The theoretical limitation is quite a lot larger that "infinitely small" due to powder particle size. Even with extremely fine powder, the laser limit would be defined by wavelength of light and thermal dissipation into adjacent material.

    The practical limitation is most likely the resolution and repeatability of the axis drives for the print head. Maximum distance for assured fusion would be dependent upon absolute orientation and alignment of adjacent powder particles and is therefore a bit (for lack of a better term) fuzzy.
    TOM_TOM_TOM Well-Known Member
    I read from the PA 2200 data sheet that the average powder size is 60 microns (0.06mm).
    How is the laser applied? Is it by moving mirrors, or is it running on stepper motors and tracks?

    I would assume it's by mirror, but a stepper motor / rod seems to run about 0.005mm per step.

    Maybe if I imagine the powder as a honeycomb, 0.03mm would activate the next half row of 0.06mm powder.
  6. AmLachDesigns
    AmLachDesigns Well-Known Member
    Is this not related to what distance the build platform moves in each step?

    Only true in the vertical direction for sure but since the question relates to a (circular) axle, possibly still relevant.
    Last edited: Jul 6, 2013