r/Altium•
JCDU

Rotation direction & P&P coordinates

Questions

Altium version 24.6.1

Is it normal that rotating something on the PCB +90 degrees causes it to be rotated 90 degrees counter-clockwise?

This feels at odds with every other coordinate system I've used and is about to cause us confusion when transposing pick & place data to suit boards that are travelling sideways through the p&p machine.

I'm knocking up a small script to transpose the pick & place output into the correct format for our machine and when I perform a rotation calculation on the output it disagrees with what Altium thinks - if I rotate everything +90 as basic trigonometry suggests is normal I get coordinates that match with what Altium thinks is -90 degrees rotation.

Here's some example data:

|| || |Altium Original|Altium Rotated -90|Script Output +90| |X|Y|Angle|X|Y|Angle|X|Y|Angle| |23.6309|12.25|180|12.25|-23.6309|90|12.25|-23.6309|-90| |92.5|-0.5|90|-0.5|-92.5|0|-0.5|-92.5|180 |

|| || |57|-0.376|180|-0.376|-57|90|-0.376|-57|-90| |50.25|15.5|90|15.5|-50.25|0|15.5|-50.25|180| |18.75|13.3492|270|13.3492|-18.75|180|13.3492|-18.75|0|

Posted Aug 4, 2025, 4:35 PM UTC

18
Loading comments…