I have some custom components built. Some of the components are showing as off-grid in schematic. I am attaching the screenshot of the component designer and schematic designer. Can someone please tell me how this can be fixed?


This is the component


This is the schematic. Few pins are off-grid.


2 Answers 2


Let me elaborate on @DanMills suggestion:
(a little too long to fit as a comment)

Altium SCH historically used a unit-less grid spacing for schematic (DXP Units).
All SCH symbols were made using the default pin spacing of something like 10-units. All was well.

Then a awful decision was made to add units to SCH drawings. Nobody can really justify why this would be a "Good Idea"(tm).

DXP-units became 'mils' and an option of 'mm' was added as an alternate grid.

Now whenever a new unsuspecting user chooses 'mm' as their SCH or library grid, everything breaks when trying to connect wires. The root cause involves rounding errors when switching from metric to Imperial grid settings.

Use only the Imperial grid in SCH and SCH libraries! Otherwise you are on your own, and all previously made SCH libraries, and most previously made SCH parts, will be off-grid.

  • \$\begingroup\$ "Error due to rounding off during unit conversion", that made my day... Thank you very much! I rechecked the units in all the schematics and libraries and made sure they are using the same unit system and they are just fine now. Thank you again. \$\endgroup\$ Nov 29, 2018 at 4:27

Move pin 1 up, so it is on a solid grid line, and move pin 3 down likewise - so the pins are 3 full grid spaces apart.

  • \$\begingroup\$ You need to redraw that particular symbol in the library as Peter Bennett mentioned. \$\endgroup\$
    – stowoda
    Nov 28, 2018 at 6:58
  • 2
    \$\begingroup\$ Usually this happens because of a metric/imperial units setting difference between the library designer and the layout sheet. You will find that most AD libs use an imperial grid for schematics and it is generally easier just to go with that. \$\endgroup\$
    – Dan Mills
    Nov 28, 2018 at 10:25

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