A kind person has pointed out that the 1P3T switch in the BOM for the RGB Matrix Input module has a collar that is slightly larger than the panel hole, which makes it difficult to correctly fit the module together.
Solution 1: different switch
If you haven’t already purchased switches for your boards then please get this one instead: 118-1MS3T1B1M2QES (Mouser code). According to the datasheet it doesn’t have collar. Alternatively a suitable switch (much cheaper) is available from Tayda (part number A-3187).
Solution 2: enlarge the hole
If you have the switches already then you can use a ‘stepped drill’ to gently widen the panel holes until it’s wide enough for the collar. Drill each one out slowly, from the rear side of the panel, and keep checking and working slowly until the switch body is flush with the panel.
Sorry about this - originally I used Tayda switches, but early feedback was to provide the BOM with single-source of parts, so I found a Mouser part that I thought would be compatible instead
I’ll make the panel holes slightly larger on future designs, so if you bought these switches then hold on to them and they won’t go to waste.
As always if you have any questions then please get in touch.