Delta Calibration Assistance

Eddiie

Hi,

I have read many pages on the www, worked to correct tower errors, worked to ensure everything is as straight as possible.

Before moving to diamond head, this printer has printed many objects OK.   Moved to Repetier firmware.

I have calibrated the printhead so there is perfect pressure on the printing plate and even on all three axis.

When I send the command to go to 0,0,0  There is about a 3mm difference between the center of the print bed and the outside towers.

I know the bed is flat, at least flat enough where a 3mm dip would be noticeable.  I have used squares, levels, and measurements, the bed is flat.

Why does the hotend sit 3mm higher in the middle than the edges?  More important, how do I fix this?

Distortion?

#define DISTORTION_CORRECTION 0

#define DISTORTION_CORRECTION_POINTS 5

#define DISTORTION_CORRECTION_R 100

#define DISTORTION_PERMANENT 0

#define DISTORTION_UPDATE_FREQUENCY 15

#define DISTORTION_START_DEGRADE 0.5

#define DISTORTION_END_HEIGHT 1

#define DISTORTION_EXTRAPOLATE_CORNERS 0

#define DISTORTION_XMIN 10

#define DISTORTION_YMIN 10

#define DISTORTION_XMAX 190

#define DISTORTION_YMAX 190

Also have baby stepping enabled mupltiplcator 1

and #define ALLOW_QUADSTEPPING 1

 

EEPROM,

Corr diagonal A, B, C,   set at 0

Delta Rod Radius A, B, C  set at 0

Tower endstop Offsets A,B,C  set at 0

Where should I look to understand what is hapenning here?

Eddiie

Bump....

UniversalRemonster

It sounds like your Horizontal Offset When Centered value is wrong. This setting effects the "dishing" of the effector as it moves around. Please see the attached screenshot.

Note that it could also be a Endstop that is offset or trimmed poorly. This is easy to recognize since the 3mm difference would only be local to a specific post. 

tierod

In my quick notes(jotted down when reading some where) it says if nozzle good on edges of bed but too high in the center, lower "horizontal print radius when centered" (see above diagram ).
NOTE: Always readjust/check z height after doing this because as middle goes down, out edges will go up changing starting print height. This can be found and changed in eeprom. Start wilh a little change in case I have it backwards.

tierod

Sorry, " horizontal radius when centered"