Still exploring the Festool's DOMINO.
Since this thing looks and sort of works like a biscuit joiner I assumed the presets for the fence were the distances from bottom of fence to the center of the mortise. Lacking a metric ruler or caliper I didn't notice that the center of the mortise for each of the presets was actually be cut at half the expected distance from the fence.
Then I realized that I was going at things all wrong. The Fence to Mortise Centerline was designed to work with specific stock thicknesses - and THAt is what these presets are for - given stock of the corresponding thickness, each preset will cut a mortise centered on the stock thickness. This is in keeping with the DOMINO's "symetric" approach
- reference your mortise of either built in, retract- able "stop pins" and you cut a mortise with the long axis center exactly at 45mm from either stop pin. That means you can reference off the right side of a part and one reference face, flip the piece around to reference off a mortise on the face 90 degrees away - from the LEFT end using the left stop pin.
So if you start with the stock thickness that matches one of the presets they will automatically center your mortise in the center of the thickness. That means that if you accidently reference off the face opposite the one you wanted to reference off of - you still get the mortise in the same place WITH NO LAYOUT LINES - NO CENTERLINE, NO MORTISE STOPS.
These fence to mortise centerline also comes in real handy when you want to do a "step back"/ "reveal". Imagine a 1 1/2" x 1 1/2" square table leg and you want to mortise and tenon the 5/8" (16mm) thick so the outside face of the apron is set back from the outside face of the leg by about 1/8" (3.5mm). It is not only easy to use the DOMINO to do this - but with just the two necessary presets written on the inside (non visible area) of the two parts - you can do it exactly the same - an hour later, a day later or a year later. Imagine trying that with the Leigh FMT jig or a dedicated mortising machine. Your layout lines are inside the joint.
If and when I can restore ftp uploading to Adobe GoLive I'll be putting up some more pages on things I haven't seen anywhere about the built in capabilities of the DOMINO. Have posted two illustrations to alt.binaries.pictures.woodworking that may make the text description above a lot clearer. Subject line is the same as this message.
Questions, suggestions etc. to improve the two illustrations will be appreciated.
charlie b