.15 fit clearance mistake. Excess on cab interior ?

[TonyGiunta]

I made the mistake, again, of making my fit clearance .15 instead of .015. PS shop running batch has told me that the excess is in the dado (blind dado) for a DECK, for example, is on the top side towards the cabinet interior. How can that be?

Why wouldn't the excess be towards the bottom of the end panel where you would not see the gap? Wouldn't the material thickness setting dictate where the top side of the dado be cut so that the bottom of the deck flushes out with the bottom of the end panel? I don't get it. 8 sheets out of 12 were run already and this mistake was picked up. Now trying to determine what to do. Thanks

[TonyGiunta]

Does the fit clearance come off the tenon or dado on blind dado joint?

[Clint Buechlein]

Tony,

Fit and Depth Clearances are applied to the mortise. The fit clearance is divided by two and applied to the two sides of the mortise. So if you have a fit clearance of .01" and a mortise that is supposed to be .375" wide, it will now be .385" wide with .005" being taken off each of the two walls.The tenon thickness is based on your percentage of material thickness setting. The length of the tenon is based of the depth setting. Depth clearance is added to the mortise.

-Clint-

[TonyGiunta]

Thanks Clint. I never knew that. So in an extreme case error like mine i.e. .15 fit. then double insult of visual gap/ non alignment to top/bottom of end panels.