I built a delta 3d printer (like a mini Kossel) and now I'm trying to calibrate it. I made all the horizontal and vertical bars myself with wood and I bought angle joints (between bars) made with 3D printed ABS.

It passes all tests in Z correction tools calibration. I used a z-probe (with manual deploying) to calibrate it with G32 and G33 commands.

Now I'm trying to calibrate the distortion that takes place on the x and y axes.
Basically what happens is that in a test cube of 10x10x10mm it is translated on x and y axes at some points in the corners.

Below an explanatory image:

The dimensions are good (less than half of a mm) but got this bad visible distortion (about 1 mm or less).

There is a tool or a command in Repetier-host/firmware that corrects this issues?

$\begingroup$i myself find same problem with my machine after searching i found out my frame of printer is bend at 2 degree angle at x axis so my all printed object are printed at that angle of 2 degree in x axis. so we need to straight our frame but it is impossible to do for me. So if you found something please inform me as well.$\endgroup$
– Akshay RautSep 10 '18 at 7:24

$\begingroup$Not an answer as specifically requested to use Repetier, but please note that Marlin Firmware has skewness compensation implemented. This is implemented in the configuration file, and found under header Bed Skew Compensation. You basically print a square and measure the diagonals and insert these measurements into the configuration file. This should be used as a last resort, it is better to fix the geometry of the hardware.$\endgroup$
– 0scar♦Sep 10 '18 at 8:05

1 Answer
1

Skew distortion in deltas means there is something physically wrong with your printer build, such as the towers not being evenly spaced or being tilted. The first thing you should do is confirm the mechanical build -- measure the distance between towers, angles between towers, parallelism of all three towers, and perpendicularity of all three towers to the bed. If you post photos of your build, we might be able to provide more specific advice.

If you can't get the mechanical issue sorted, it's possible to calibrate out some specific build errors (like skew due to uneven tower angle), but that's nearly impossible to do "by hand." You really need to use a Z probe and auto-calibration sequence such as in Rich Cattell's Marlin fork or dc42 RepRapFirmware.

$\begingroup$Hello, i update the question with more info. I know that there is something wrong in my build (nothing is perfect) but what i'm trying to do is to correct this imperfections in some way (preferably via software).$\endgroup$
– xxxJul 7 '16 at 18:36

$\begingroup$The way you describe your build, it might not even be possible to get all the errors calibrated out. Deltas require fairly high fabrication precision to produce dimensionally accurate output -- auto-calibration can fix moderate errors but not big ones. This is simply the reality of the deltabot architecture. Cartesian printers are much more tolerant of low-precision construction.$\endgroup$
– Ryan CarlyleJul 7 '16 at 19:49

2

$\begingroup$And to answer your main question, Repetier doesn't currently have a full-fledged delta auto-calibration technique that can fix skew distortion. It can only do bed tilt and bed grid mapping to my knowledge. You'll need to switch firmware or use David Crocker's manual calibration tool. See my answer to this question: 3dprinting.stackexchange.com/questions/1460/…$\endgroup$
– Ryan CarlyleJul 7 '16 at 19:52