Re: [Machinekit] Linear Delta dimensional print failures

[schoone...@btinternet.com]

On 24/06/16 10:58, Bas de Bruijn wrote: On 24 Jun 2016, at 11:12, Ed van den Enden <evde2...@gmail.com> wrote: My Delta Printer with BBB rev C, BeBoPr++ and pepper board print in a very consistent way dimensional failures. The slicer I use is Slic3R Test parts of 40x80x3 mm or 100x100x5 mm all do endup with the same dimensional failures. Print speed has no influence on the dimensional failures. (Printed at 80 mm/sec) Mechanical variables I did I eliminate or minimized: Renewed the arms; Arm length (292) tolerance Center to Center within 0.03 mm Real play in joints is near to "0" (Magnet joints) Bearing blocks play, near to "0" Build Bed Leveling within 0.03 mm  The poles are dead square to the build bed What is exact the failure I can observe: When printing a straight line that is centered on the bed plate, just over the center of the line the line seems to make a jump of 0.25 mm; printing a rectangular shape mean that exact the same happens again on the opposite side of the first straight line. (See picture 40x80x3mm) It happen only along the X-Axis, the Y-axis is nicely straight. In general holes are not round. (~0.3 mm) Has anyone an idea what is going on here? Is it the linear delta algorithm that fools me or is it me doing something terrible wrong here? My guess is that it’s something mechanical. Seconded If you have parallel tracks, screws, slideways or whatever, and there is the slightest divergence from absolute parallel, there can be a pinch point along the length of the track where is binds slightly What people often do is have one slideway rigidly fixed and allow the other to 'float' slightly by loosening the fixings If that cures it, you know what your problem is. Sometimes the last fractional turn of the fixing bolt, is enough just to skew things slightly. Good luck Looking at your picture, your nick that your point to (arrow) is guesstimated at x,y of (20,10). I think I see the same nick at (-20,-10) Have you checked the other dimensions of the parallelogram? the center distance between the 2 arms in one parallelogram. Those dimensional tolerances are _as_ important as the arm length. You mention holes being not round, in what respect? are the x dimensions off, or the y dimensions? Need help, please   -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.