Domino cutter slots too tight for dominos.

[ChuckM]

I, too, use glue in every domino project even if the dominoes are for alignment purposes as in the case of a panel joint and not for strength. When there're too many mortises (the last project saw me using over 250 dominoes) for me to handle by myself, I grab a helper.

 

[onocoffee]

I used a micrometer and measured the thickness of the dominos I have and they are the correct thickness, about 0.001" smaller than the size listed.  This means the cutters (5mm and 6mm), that came in the the Festool Assorted Domino Beech Tenons and Cutters in T-Loc Systainer, are undersize.  I need to sand the dominos a lot in order to insert them in the slot.  Is this common?

I haven't experienced swelling of my dominos like the others have noted. I will find that the dominos can feel like they're too small when I'm cutting on the tightest setting. In those cases, I will take some sandpaper and sand down the ribs on the side. I'm actually not paying that close attention to how much. I usually grab my ETS EC 150, turn it over and strike the rib on each side with a few strokes (I'm not turning the sander on) - and I'll use whatever grit happens to be on the ETS at the time. That has solved any concerns I have about fitment.

*I did get that tip from Festool Sedge in one of the videos. He also says not to sand the flat sides of the domino because those grooves are what gives the domino the gripping power, and sanding those would weaken the joint.