DWX5 51D

Discussion in 'CNC Machines' started by padano, Apr 11, 2019.

  1. padano

    padano Active Member

    My machine is not enough accurate. I tried to mill a regular shape like a cube and every time i had different measurement in X and y direction.
    EX: for a cube x=10mm y=10mm z=10mm
    i had x=9.86mm y=9.85mm z=10.03mm

    I use the Millbox with last milling strategy : 14g_Master_default_rev16g and the machine is well calibrated.


    Thanks in advance.
     
  2. cadfan

    cadfan Moderator Staff Member

    @padano what material have you milled ?? try wax and pmma and maybe zirkon with no shrink faktor to check if its a specific problem with one material vs. set burs and so on. Z value is in the range what could be expected 30 micron the rest is way off . What do you use to measure ?? is it calibrated which repeatability ?? i use a Mahr microscrew calibrated 2 micron repeatability around 160 Euro or so . I would although mill the shit a few times to see how about repeatability
     
  3. DMC

    DMC Scott Hudson

    Me too, that is why I owned a Roland for about 6 months, and sell it. (2008)

    Never had good repeat results. Impossible to hold calibration to my standards.

    Everytime you power off, and home axis again.....the coordinates shift and now machine lost calibration.
     
  4. DMC

    DMC Scott Hudson

    Home axis and go to a position......turn off machine, then home again and try to go to same position.....not possible.
    I see +/- 100um difference.

    No closed loop-encoders, home switch not accurate.
     
  5. DMC

    DMC Scott Hudson

    I use a physical dial indicator gauge.

    Mounted to chassis.

    Jog axis to a coordinate and get reading from gauge. (Dial Indicator I have touch the spindle mount surface)

    Power-cycle and home axis again.....jog to exact same coordinate and now gauge read different by +/-100um

    Roland use to post specs of repeatability being also +/-100um !!! But they remove this spec data from all literature years ago.

    No need to mill anything to see this in a few minutes.
     
  6. cadfan

    cadfan Moderator Staff Member

    one is position repeatability in space but even non encoded steppers are able to reproduce less than 30 micron even with a bit backslash or to make it simple it doesnt matter where you start milling 100 micron left or right your steppers have only to count 1 cm
     
    Last edited: Apr 12, 2019
  7. DMC

    DMC Scott Hudson

    The home switch/sensor not accurate

    The motion control system running rubber belts is not accurate.

    Yes, recently One axis changed to screw/ball and that helped the One axis.

    If we had encoders, then that would fix the sloppy drive system.

    Have you owned One of these and taken it apart??

    It is more like a paper printer, with no chassis. Missing proper rails and bearings, missing screw to drive moving parts. It is not a CNC mill.
     
  8. 2thm8kr

    2thm8kr ɹotɐɹʇsıuıɯqA Staff Member

    But you may be able to repair an old foosball table with some of the parts.
     
  9. padano

    padano Active Member

    I mill PMMA and zirconia.
    I tried to mill the same file but every time i have different result in X and Y but Z still good.
    I noticed that I have a big backlash in X an Y ball screws.

    I don't have the Jog option in my machine to perform the the repeatability check.



    upload_2019-4-12_9-57-38.png
     
  10. cadfan

    cadfan Moderator Staff Member

    @ Padano than i would say backslash is your problem ask reseller or maybe someone here knows how to repair vs preload.
     
  11. mill3d

    mill3d Well-Known Member

    Is this what causes crowns to have open proximal contacts, when there are many crowns side by side (I have 52DC)?
     
  12. padano

    padano Active Member

    who has the service manual for this machine?
     
    Last edited: Apr 15, 2019

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