Is This the Correct Method for Mounting Hole Placement?

[rayan]

I need to verify if I’m using the correct method for positioning mounting holes. Here’s my process:

1. Measure the distance from the mounting hole to the nearest edges (length and breadth) from the available reference.
2. Create a rectangle in F.Silk using these measurements.
3. Position the edge of this F.Silk rectangle at the predetermined mounting hole position.
4. Place the mounting hole at the intersection point where the length and breadth meet, using the full window crosshair for accuracy.

I’ve searched for tutorials on this but couldn’t find any, so I did it myself. Is this a valid method, or is there a better approach?

[eelik]

Certainly there are better methods.

For example, select the largest possible grid which can represent all needed coordinate points (in your case 1 mm would be good). Go to the zero point (your reference). Press spacebar. Select the item for moving so that you grab it from the center point. Move it while looking at the dx and dy coordinates in the bottom status bar of the view. Drop it to the wanted coordinates.

Or, again using the “local origin” with the spacebar. Select the item and use context menu → Positioning Tools → Position Relative to… and Use Local Origin as the reference. Write the coordinates, OK.

[paulvdh]

In my personal working method, I try to incorporate (127, 127) as an “important” coordinate on the PCB. It can be a fiducial, pin 1 of a THT connector (preferable) or else some other part. It could even be the corner of a PCB, but those are less well defined during PCB production and I tend to avoid doing that. I use (127, 127) because it’s also 5 banana units, so whether you align things to absolute (0, 0) or (127, 127) and either metric or banana units, it gives you the most chance of keeping all your grids aligned with each other.

PCB outline I usually draw on a metric grid. I am living in (mostly) civilized Europe, and we agreed upon length measurements some 200 years ago. THT connectors ans other footprints I usually place on a 100mil grid, to maintain breadboard compatibility. The atrocious arduino kludge would never occur for me. I’d rather throw the boards away and respin the boards. Mounting holes depend on the situation. Sometimes it’s convenient to drill existing holes in matrix PCB bigger, and then I put the holes on a 100mil grid. In other situations I keep things metric and in whole mm for anything mechanical.

eelik already mentioned the space bar to reset relative coordinates, and Context menu / Positioning Tools / Position Relative To. Another method is to select your hole (or hover over it, and press e to edit it’s coordinates. You can then directly enter numbers or simple formula’s in the entry boxes either in the properties window of your hole, or in the properties manager on the left side of the screen (if that is enabled).

[Piotr]

@rayan

is there a better approach?

To create Silk rectangle you have to find right positions so why not find it when at once placing the hole.

In KiCad V4 V5 it was not possible to work with absolute origin other than in top left sheet corner so I decided to place my PCBs having this corner inside PCB at my 0,0 position (if my description is not clear - see here: Resize page to all what was plotted when plot PCB without drawing sheet. (#18496) · Issues · KiCad / KiCad Source Code / kicad · GitLab ).
I have changed frame at PCB editor to contain only small cross at 0,0 position.
I place holes simply looking at absolute x,y at status bar.