Solved Corner mismatch

Usually very small deformities like this are the result of the jerking motion trying to decelerate or accelerate the head when it changes direction. The Robo used defaults from Marlin in these areas which are just too fast for the hardware provided, you can experiment with the acceleration values if you are usb connected with the M201 command. I recall, but might be mistaken that both X and Y default to 9000, and the number should probably be closer to 900, you could set X and Y with a single code like this

Code:

M201 X900 Y900

Once you find a values you are happy with, change the following lines in Configuration.h from:

Code:

#define DEFAULT_MAX_ACCELERATION      {9000,9000,100,10000}    // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

to this:

Code:

#define DEFAULT_MAX_ACCELERATION      {800,800,100,10000}    // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

replace the 800 parameter with the ones you find are okay for your machine.

 

What silcer?

 

You should ping their support people with these details. There are a lot of settings to play with and they can point you in the right direction.
For completeness, try another slicer and see what the results are.

 

I am sure you can get it tweaked to what you want.

 

Since your two sample are a bit different (filament wise) it is hard to compare apples to apples. but your image may be showing an ever so slight over extrusion, what happens if you lower the extrusion multiplier by .01 or .02?

 

Is your extruder properly calibrated? Is the Robo defaults still in effect?