changing footprints - Page 1
Forum section: electronics / general

author: Lyndsay_Doyle
author_rank: Contributor
timestamp: July 13, 2023, 07:32:00 am
content: Can anyone give me an insight as to why Altium AD22 decided that it should change the footprints on my design?I had placed components from a library.I added a few components as a result of a design mod.Nothing spectacular just adding some ESD chips.I then updated the design to PCB. Nothing in that.New components appear.So far all expected.To my horror I notced that some inductors have the footprints changed to some random footprint and library that is not what is on the schematic.WTF. I only noticed when I was routing near the inductor and wondered why a track was off the pad.Why would Altium do this?Only wasted half a day and good job I have a backup.I wish I had never bought Altium. I have said that a few times over the past six years.

author: Pseudobyte
author_rank: Frequent Contributor
timestamp: July 13, 2023, 12:37:24 pm
content: It's always best not to blindly approve ECOs when pushing changes from your schematic to layout.No matter what CAD tool I'm using I trust it about as much as I trust a stranger. That being said always do the needful and review the ECO for unexpected changes.

author: ajb
author_rank: Super Contributor
timestamp: July 13, 2023, 04:46:43 pm
content: Having just responded to your other thread and then seen this one, everything I said there applies here as well. The PCB footprints changing is likely a symptom of the symbols in the schematic getting updated somehow. If the components in the sch are replaced with different ones with different footprints assigned, then the footprints are going to get updated in your next SCH->PCB ECO, unless you specifically uncheck them.

author: thm_w
author_rank: Super Contributor
timestamp: July 13, 2023, 09:12:02 pm
content: Yeah, 99% chance you've named some footprint the same as another library and not specified in the symbol which library it has to come from. So it grabbed a part from somewhere else.Just opening a file or project in AD will never make any changes to it. You always have to do something first.

author: asmi
author_rank: Super Contributor
timestamp: July 17, 2023, 02:50:13 pm
content: That's why you are supposed to pay attention to what you see in a ECO window instead of simply clicking "Execute". If you see something that should not be there, you don't execute an ECO and instead go and investigate what caused this unexpected change.

author: mengfei
author_rank: Regular Contributor
timestamp: July 19, 2023, 09:56:01 am
content: clear out your library & just use the one you know that footprint is the right one, multiple libs with same footprint name but different shapes can mess up your work

author: Psi
author_rank: Super Contributor
timestamp: July 19, 2023, 11:30:36 am
content: I dunno about modern altium, but older versions had the option for the footprint of a components which set if you wanted to use a specific footprint in a specific library, or use any footprint in any installed library with the correct name. If you had it set the latter and used a common name I can see it getting confused and picking something other than what you had intended.Also FYI, if you update SCH to PCB and then notice your PCB is all messed up you can always just undo that change like you would undo anything. The PCB update is part of undo history. Obviously you need enough undo-history to get back to the change if you didnt notice right away.I use that from time to time, Update SCH to PCB, ops that's wrong, CTRL-Z