Delta X-Axis Accuracy issues
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@joergs5 it theoretically could be warped, but it's a circular mirror, and happens on all areas on the bed. And a G29 produces a pretty nice grid.
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@joshc4566 I searched for "delta printer different x y" and found some information interesting:
comments of hercek:
https://reprap.org/forum/read.php?178,380688,381527comments of Doug LaRue:
https://groups.google.com/forum/#!topic/deltabot/q65tcjykI4kFound additional possible reasons, e.g. that the J-Head must be mounted straight and you should calibrate with autoleveling off.
Maybe you find something.
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@joshc4566 a very interesing calibration guide, with Duet3D correction codes:
http://www.sublimelayers.com/2018/03/musing-how-to-print-accurate-parts.html
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@joergs5 that's a pretty awesome article. I might try that, but since my issue isn't consistent across the print bed, I think it will only help on smaller objects. I'm going to re-print some parts, tear it down and rebuilt again. Just to eliminate any discrepancies in the adapters for my magball ends I may have. Also, how important is 100% even belt tension?
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@joshc4566 as far as I know, it is not important, because every belt has its own stepper and they are independent. It is important to have enough tension to avoid backlash.
At CoreXY printers it is important because the XY steppers are correlated.
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@joshc4566 my main bet is that the aluminium extruders are not perpendicular, i. e. they are not parallel to each other. The difference of the printed object is in the whole object, but is small enough to not being visible in the middle (because the rods are in middle height position), and at the edges one of the rods is at high position and error is maximized.
To measure parallelity of the aluminium extrusions, you could use your linear guides: connect them pairwise with a horizontal shaft where the rods are connected, and move the guides up and down. If this stucks, you know that they are not parallel. Repeat it for all three combinations.
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@joergs5 sorry for the huge delay! It's been a crazy busy month. I went and got married and had my honeymoon band have been out of the game for a month, but I'm ready to come back at it strong! I can't really seem to find much I'm the way of the extrusions being off from each other. I can't really connect the carriages to see if they bind, but using my metric tape and digital angle gauge, everything seems to be super square. I've even replaced the vslot wheels and bearings.
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@joshc4566 Congratulations for you marriage, I wish you all the best!
Regarding the printer, I would search for differences first:
- is there play (backlash) in the connections
- something not flat
- lengths, even if sub mm
- stepper speed settings (you can slow down printing in case one of your steppers looses steps). You can exchange the steppers (I mean exchange the existing ones) in case one is defect or inaccurate a bit
- every pulley, belt etc. fixed
- belt tensions
Maybe this link and their sublinks are helpful:
https://www.3dhubs.com/talk/thread/delta-printer-printing-dimensions-wrongThere are Tevo Little Monster specific calibration on thingiverse:
https://www.thingiverse.com/thing:2722557
esp. the forum links with some additional ideas.And Duets own know how page:
https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printerHope something helps, as I cannot help you directly.
PS I forgot: please make sure by using one of the calibration tools on thingiverse that your stl file is not the cause.... this would be a bit annoying.
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@joshc4566 This user had problems on one side of the print also:
https://forum.duet3d.com/topic/5119/tevo-little-monster-mesh-grid-results
Maybe you find your reason in this thread. -
@joshc4566 Here is another interesting blog:
https://tevo-3d-printers.com/viewtopic.php?t=295
Even differences of 0.1 mm matter!
