Why does print time go up when I rotate the print 90 degrees?

[TomniSells 0]

Hi, I'm running into a case where if I simply change the orientation of a rectangle, it adds a few minutes to the print. I don't see an x/y acceleration or speed setting anywhere for separate axes. Is it hidden in some other setting panel? I can only understand this through a difference in the x vs y speed. Is there something else afoot that I'm not seeing?

[gr5 2,210]

I'm thinking it has to do with the corner of your print where it changes layers.  Instead of rotating the print try changing the corner.

Layer Start X

Layer Start Y

 

If zero I think it defaults to back right corner?

[GregValiant 1,330]

@gr5 I think it has to do more with the "Line Directions".  When you spin any model in Cura you do not spin the skin pattern or infill pattern.  If the infill (especially Lines or Grid) and Top/Bottom are printing at [45,135] and a rectangular part is square to the world then although it is filling the same area, some lines are shorter, some longer, and there are 41.4% more lines which means more short index movements at the end of each extrusion.  If the part is spun to an orientation of 45° then it would be aligned with the skin and infill at [45,135].  All those lines are of equal length and you have limited the number of index moves.

 

Within Cura your Accel and Jerk are set the same for both X and Y.  You can alter the Accel by adding a line to your Start-Up Gcode

By setting a different Accel limit on the Y axis than the X axis:

M201 X500 Y300

Then in Cura if you set the Print setting for any feature to 500 the printer would limit the Y to 300.  Some people do like to put a lower limit on the Y because of the weight of the table.

Jerk is different because there is no "limit" command.  You would have to alter the line that Cura puts into the gcode.  F'rinstance, Cura might put in M205 X10 Y10 and you would need to change that line like M205 X20 Y10 or something.

 

I'll stick in Greg's Accel and Jerk Tool.  It's a little Windows app and a sort of calibration tool for accel and jerk.  You can separate the axis for both Accel and Jerk and see how it affects movement of the print head at various speeds and around circles.  There is a utility for leveling, and also for printing from the SD card as well.

Greg's Accel and Jerk Tool.zip