Confusion over the Festool Domino and widening the mortise...

[Robert Mayer]

I have a domino coming in tomorrow, after drooling over it since it came out. I was watching some YouTube videos on operating it and noticed you can make the mortise wider to keep the joints from becoming too tight.

From the videos it looks to me like even on the 2nd setting the tenon is very loose from side to side. Doesn't that really affect the strength? Does it make a full cure take longer?

Do you guys actually use that feature or just leave it on the tightest setting? Seems to me that careful fence usage and technique would eliminate the need to widen it.

[Jim Becker]

When there will be a whole bunch of Domino tenons used across a joint, it can take some really careful "perfection" to be able to do them all on the "tight" setting. So it's common to set the center one on "tight" and the rest with slightly wider settings so you can actually get the assembly together. The Dominos are still tight vertically...the only wiggle room is width. Once things are glued, it's very strong.

You absolutely "can" do all the mortises on the "tight" setting if you are extremely careful with lining things up, of course. You can always revisit a cut if it's off just enough to inhibit putting things together. The "tight" setting really is just that..

[Clark Hussey]

I cut all my mortises the same size. There will be a learning curve to getting them to line up. So do a lot of test cuts before, using it on a project.

[Ralph Okonieski]

After first acquiring my Domino, I used a wider settings for a short time. After reading the supplemental manuals, I calibrated the machine to make sure it was cutting true. After that, only the tight setting has been used successfully. I can not remember the last time a wider setting was used. It has been more than 10 years since it was calibrated and the tight setting is still true.

[glenn bradley]

The wide size can also be handy for wood movement similar to slotted dowels. The Domino excels in sheet good cabinetry but has found a home in solid wood construction as well.

Kellogg Inspired Wall Cab (139).jpg

[Jim Becker]

The Domino excels in sheet good cabinetry but has found a home in solid wood construction as well.

I don't believe I've every used my Domino 700XL with sheet goods to-date, even though I do have the DF500 cutters, Dominos and the Seneca adapter that would permit it...I actually bought it for solid stock construction!

[johnny means]

I almost always just go with a tight fit. But, it can get difficult if you've got a 14' edge with 30 Dominos. At this point a few small discrepancies become a joint that just won't go together.Sometimes with really complex glue ups, that last joint needs some flex to be able to "close the circle". Also, sometimes I'm not using store bought Dominos at all, but doing regular tenons. Not to mention the times when a certain length slot is just what the doctor ordered. I recently had to build several drawer units to bolt into structures that I would never see. The Domino was the perfect tool to cut mounting slots for easy up and down, on site adjustability.

[Mike Henderson]

As Jim mentioned above, you can do one mortise "tight" and the rest at the second width. But for most things, I only use the tight setting. It's not that difficult to get the mortises in the right place.

I have used the wider setting for a few things. One project was to accommodate wood movement. I glued the center domino into both pieces and then the rest of the dominoes only on one side. Other times, I made a regular tenon and made the mortise to fit. You just move the domino after the first plunge to widen the mortise. That allows you to make a mortise as wide as you want.

Mike

[Jacques Gagnon]

The approach used for marking can also play a role in this equation. Lining up the Domino on a knife line perpendicular to the edge will generally result in better accuracy than when drawing an approximate tick mark with a lumber crayon that is 1/8 inch wide (sorry for the « slight » exaggeration).

[Andrew Hughes]

I make my own dominos making them slightly smaller then the mortise does the trick.

[Dan Friedrichs]

Jerry Work's Domino manual is an excellent read as you're first getting familiar with the tool: http://thedovetailjoint.squarespace....%20reduced.pdf

[Kevin Jenness]

If you are careful laying out and aligning the center marks with the machine in use you can do multiple mortises on the tight setting. Using the wider one will not detract much from the glued joints' strength, but the mechanical strength of a tight fitting tenon in a door frame or the like should not be ignored. You can gain a little wiggle room at the tight setting by shaving the spines off the domino edges. A 0.5 or 0.7 mm mechanical pencil makes a consistent fine center mark.

One excellent use of dominos in cabinetwork is to plunge through a partition and run a domino through it into a shelf on either side for perfect alignment. This works well with a Domino 500 on 3/4" material as the baseplate can be registered to the shelf face with no offset just as you would use a biscuit joiner for a tee joint.

[Prashun Patel]

I use the wider setting often on large panel glue ups where I want flush joint alignment but am relying on the edge to handle the glue.

On joints that many get stressed in the longitudinal direction of the mortise, I try to use the tight setting .

[Johnny Barr]

If I can reference of the paddles or use the trim stop accessory or some sort of stop block or spacers then all my mortises are set on tight. Even if I use a pencil line I still use the tight setting and if its slightly off then I re cut that mortise on the wide setting. The bottom line given the comments here is use the tight setting wherever possible.

[George Yetka]

Just did a 5 board table top glue up. After marking it up I ranthe domino in the #2&4 boards on the middle setting. It makes assembly a bit easier