Custom footprint for vacuum tube based on connector

I hereby certify that I am not simply asking someone else to design a footprint for me.

Let me start by saying this is my first kiCAD project and first post here but this is not my first rodeo.
I thought I’d try a schematic and PCB layout for a guitar amp with tubes. My goal is to create a schematic that looks like it should with custom connector footprints assigned to those components that are off-board. Ought to be easy enough…

( The triode is actually a 9-pin device but the other 3 pins do not connect to the board.)
I want pins 1,2,3,6,7,8 of this triode to assign to a 6 pin “connector”:

that looks something like this:

However, when I go to the PCB layout, it’s not wanting to connect to the pins I’m calling 8 and 7:

It most likely has something to do with skipping pin numbers, but this doesn’t seem like an unreasonable thing to do. Is this even possible?

There can be several reasons for this. The most logical would be that you did not update the PCB after a schematic change. KiCad does not automatically synchronize between the schematic and the PCB, and you have to Schematic Editor / Tools / Update PCB from Schematic [F8] to do that.

Analyzing from some screenshots is also mostly guesswork. If the above does not work for you, it helps if you just zip up the project and post it here.

Hello and welcome @clark

Did you create your own footprint, place it in your personal library, then assign that footprint, in your library, to your tube?

Yes, I did. My first attempt used a copy of a stock “wire connector” from the library, modified to omit the middle pin. This seemed to connect okay but the size and spacing were all wrong. So, I downloaded a footprint from Mouser for a standard 6-pin connector of the proper size, modified that, replaced the footprint in the schematic, updated the PCB from schematic, and everything went sideways.

The Kicad footprint (loaded into your personal library) worked (the ratlines were all there), but the Mouser doesn’t, is that correct?

If you want to generate a row or two of pads, try using the S-DIP footprint wizard. You have to watch out for third-party symbol and footprints. Often they waste more effort than they save.

Yeah… I modified the pad size a little and the numbers. Maybe I’ll try again to decipher the wire_connector naming convention and use one of those.

Sorry, didn’t understand your reply… did the Kicad footprint work properly… just the wrong shape/size?

I thought it did; now I’m not convinced. I just took another look at it and the pins are numbered 1 - 6. I don’t see how it could make the right connections.

This kicad connector is in your personal library now, or is it in the kicad library?

Affirmative. And modified…

It is just the wrong size/shape?

@clark What I’m trying to find out is if the the kicad footprint works, but doesn’t fit, and if the Mouser is a dud footprint.

Why even do something with some mouser library?
KiCad has quite capable editors for either creating footprints from scratch, or modifying existing footprints.

If you already have a footprint on the PCB, then just select it and press [Ctrl + e] to edit it in the footprint editor. When done editing, just close the footprint editor, and KiCad asks you to push the changes back to PCB. You probably already know part of this as you write you already modified some existing footprint.

But this is now the 14th mail or so in this thread, and with not much progress. It’s much easier to have the project itself to diagnose what is going on.

It’s not that. I just tried to change the footprint back and it wouldn’t even change it. Also every other time I update the PCB I get a slew of errors about “Pad not found in Connector_Wire…” This is getting old fast.

The footprints are not part of the project,. So there’s that. I downloaded the footprint for a connector that I knew had the right footprint for my application since I can’t find any explanation for the naming convention for stock connectors, namely “Connector_Wire”.
None of this addresses why it won’t connect a pad numbered 7 any components that are connected to pin 7 in the schematic. Does it?

We’re getting nowhere fast.
Back to the beginning.

  1. You took a kicad footprint from a kicad library and placed it in your personal library?
  2. You modified that footprint (now in your personal library) by changing the pad numbers?
  3. You associated that now modified footprint in your personal library with the tube symbol?
  4. That footprint was the wrong shape/size but you had correct ratlines on your PCB?
  5. You went searching in Mouser?

Could you give a yes or no for each number?

That is essentially correct except I’m no longer convinced the rat lines were correct and I can’t get it to change back to that footprint to verify. I guess the root question here is whether or not there’s supposed to be a one-to-one correspondence between pad number and pin number. Seems like it should be so but I’m not seeing it.


I edited 2 above, please check.
You say essentially… is that yes or maybe or no?

Yes. I modified the pad numbers to correspond with the pin numbers.