Mechanical layer, automatic change between top and bottom? - Page 1
Forum section: electronics / general

author: Korken
author_rank: Regular Contributor
timestamp: August 14, 2015, 09:03:08 pm
content: Hi all!When I make components I always add a "mechanical drawing" and a .Designator to get the outline and name of the component for when I mount the board.But there is a problem, when I place these on a board and move a component to the backside I want it to have its own mechanical layer some how.Else I get the top mechanical drawing and the bottom mechanical drawing in the same gerber file, making it impossible to use.Is there an easy way to fix this?Thanks in advance!

author: ajb
author_rank: Super Contributor
timestamp: August 14, 2015, 10:51:16 pm
content: Set the top/bottom layers as a mechanical layer pair, the menu for this is in the PCB layer dialog IIRC.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 14, 2015, 11:11:13 pm
content: Yeah, on the layer stackup dialog, you can set mechanical pairs. What happens is you get the next sequential layer assigned for the opposite layer. That is, if you have layers 1, 3 and 15 present in the footprint, the opposite side will use 2, 4 and 16 (assuming you assigned them all).It's usually okay to print assembly outputs with components only on top / bottom layer, but pairs usually gives better results. Worst example is when making a composite print, all the shapes and pads of components on the hidden side are omitted fully, even if they affect the layer of interest! So you get what looks like traces running to nowhere, when actually there's padstacks and a connector there.Tim

author: Korken
author_rank: Regular Contributor
timestamp: August 16, 2015, 12:37:10 pm
content: Thanks for the help, but I must be blind.I was able to create a layer pair for it, but the components are still all visible in one layer.It there something more that must be done?

author: exmadscientist
author_rank: Frequent Contributor
timestamp: August 17, 2015, 02:42:43 am
content: Altium doesn't change components you've already placed to conform to your new rules. You'll need to delete and re-place them, or go to Tools -> Update from PCB Libraries and replace the changed footprints with their current library versions, which Altium will place correctly on the layers using the new rules.

author: Korken
author_rank: Regular Contributor
timestamp: August 17, 2015, 06:46:27 pm
content: Ahhhh! Thank you!Works perfectly now

author: Paul Rako
author_rank: Newbie
timestamp: December 31, 2016, 05:21:37 pm
content: Quote from: exmadscientist on August 17, 2015, 02:42:43 amThank you a million times over. I just bought CircuitStudio, the stripper Altium. I was trying to get a top and bottom assembly drawing set up _before_ I imported or made my footprint libraries. I kept checking I had the two layers paired and was wondering if the layers literally had to be named "mechanical x" as opposed to Assembly Top and Assembly Bottom. I re-placed components as you suggested and it finally worked. Next I will try an update for the board I already laid out.

author: technotronix
author_rank: Regular Contributor
timestamp: January 02, 2017, 02:33:47 pm
content: You can not edit or change the components in Altium, delete it and place them again.

author: exmadscientist
author_rank: Frequent Contributor
timestamp: January 02, 2017, 09:11:20 pm
content: Quote from: Paul Rako on December 31, 2016, 05:21:37 pmGlad to have helpedNote that updating PCB footprints from libraries can be kind of buggy. I've seen several instances where some part of the footprint just doesn't update properly (particularly text strings in the library footprint). Pushing from the PCB library to the PCB (have the library open, right-click the footprint in the library list, press the Update option) seems to work better than pulling from library into the PCB (the method described above, having the PCB open and going to Tools->Update...). Deleting the footprint and letting Altium re-add it always seems to work properly.Quote from: technotronix on January 02, 2017, 02:33:47 pmHuh? Of course you can. Just uncheck "Lock Primitives" on a footprint and you can edit all you want. (It's only rarely agoodidea, but you can certainlydoit.)