I've been using my domino for a few years now and have got to admit, I think I'm absolutely terrible at using it. It's gotten to the point where I typically dread pulling it out and do everything I can to avoid it, and I'd like that to stop.

My issue is one thing and one thing only. I can never get consistent depth on the mortise location. Left to right alignment is always perfect. Everything assembles without issue. Nothing, however, ever ends up flush on the face.

Example: I was making a screen door today and I dry assembled everything prior to marking out for dominos. The stiles and rails met perfectly flush on the front and back of the door. As you'd expect since it was all planed to the same thickness. With everything clamped up I go through, mark out all of the domino locations, then disassemble.

Next I clamp all of the rails, make their cuts, set them off to the side. Then, clamp the stiles, make their cuts, set to side. Grab dominos, dry assembly. Every single rail sits proud the exact same amount on both sides, probably 2mm. Disassemble, reclamp the rails, sure enough the cutter now will not insert into the previous mortise and wants to cut higher.

So the question I'm dumfounded by is this: Is the fence somehow slipping 1/2 way through the process? If it's slipping, it would be slipping down, towards the cutter, not up (otherwise the rails would sit recessed, not proud) which doesn't seem right, I'd expect the fence to slide up due to the way the machine sits. Or, am I somehow consistently recreating a repeatedly accurate mistake on a large scale? 16 in a row that are off by 2mm and then 16 in a row that are dead on...

This is essentially the same experience I have every time I use the domino, and it's been that way since the day I got it. Occasionally things come together flush, but more often than not I end up double drilling and wondering what the point was in the first place.

I would really appreciate any advice on what I'm doing wrong here.