Panel rail spacing error

Prerequisites

[X] I have read FAQ
[X] I have searched existing issues (including closed ones)
[X] I use KiKit at least version 1.6.0 (older version are not supported)

KiKit version

1.6.0

KiCAD version

8.0.5

Operating system

Windows 11

Description

While panelising a design I usually use these frame settings as required by PCBWay:

type = railstb (top and bottom) vspace = 1.6mm width = 5mm

I would then expect that the space between the rail and the boards be 1.6mm. However, when looking over the panel I discovered that actual vertical spacing between the rail and the board was 1.601mm as shown. actual_spacing

The offset error is also observed within the .pos file for component placement. pos_file

This erroneous behaviour also appears with the frame type set to left and right rails, but does not appear when whole frame is selected. I have confirmed that an older revision of this board from October 2023 doesn't exhibit this error, I am unsure what version of KiKit was used at that time.

I am aware this is a wee bit pedantic, but whole metric number make brain happy :)

Steps to Reproduce

Kikit JSON preset:

{
    "layout": {
        "hspace": "1.6mm",
        "vspace": "1.6mm",
        "rows": "6",
        "cols": "4"
    },
    "tabs": {
        "type": "fixed"
    },
    "cuts": {
        "type": "mousebites",
        "drill": "0.55mm",
        "spacing": "0.9mm",
        "prolong": "0.9mm"
    },
    "framing": {
        "type": "railstb",
        "vspace": "1.6mm"
    },
    "tooling": {
        "type": "4hole",
        "hoffset": "2.5mm",
        "voffset": "2.5mm"
    },
    "fiducials": {
        "type": "3fid",
        "hoffset": "5mm",
        "voffset": "2.5mm",
        "opening": "1.7mm"
    },
    "text": {
        "type": "simple",
        "voffset": "2.5mm",
        "text": "RAZFL-244HMCF - LEVEL SHIFTER PCB R2.1 - 4 X 6 = 24"
    },
    "post": {
        "millradius": "0.8mm",
        "origin": "bl"
    }
}

Input board: input_board.zip

Generated Panel: panelised.zip

yaqwsx / KiKit