[SOLVED] Differentail Pair thickness is wrong when routing USB

[mameco3798]

Hello All,

I am trying to route a differential pair and it always seems to pick the wrong thickness to start.
Here is what I am doing:

1. Set up the differential pairs in board setup:
   
2. Assigned nets to that named class:
   
3. Set kicad to use the net class width:
   
4. Start a diff pair routing with keyboard short cut 6:
   
   

No matter what I do in step 4, the default track width is 0.12mm (and not the 0.247mm as expected)
What am I doing wrong?
Thanks.

[paulvdh]

That’s because “Differential Pair” is “DP” and those have their own settings in the Board Setup

[mameco3798]

Thank you. That solves the immediate problem.
But I still don’t get what the point of assigning the nets to a class is if reverts to “Default” class’ DP width and Gap
Or maybe it is just a workflow I need to get used to.
But once again, thanks. That solves my problem.

[paulvdh]

@mameco3798

But I still don’t get what the point of assigning the nets to a class is if reverts to “Default” class’ DP width and Gap

I think you missed something. Each class has two settings, one for “normal” tracks, and one for differential pairs.