Domino 500 connector rotation

[nvalinski]

I have a design for a relatively straight forward nightstand that I've been attempting to turn into a flat pack, shippable piece. I've been exceptionally excited about the new 500 connectors coming out, only to realize that they don't actually prevent rotation. They're certainly more robust than your typical camlock RTA connectors and appear to have better pullout strength than the Dominofix connectors, but the need to have a second domino on every joint to prevent rotation seems like a missed opportunity.

My question is, for any owners of the system (700 works too for comparison, is the lack of rotation control actually a problem, or do these tighten up enough on their own to not need it? If they need rotation control, have you seen any ways to do it without the addition of another dowel/domino? The rails for my piece are only 1.5"x0.75", so there's not exactly much room for a second piece. Perhaps there's a better solution than the new Domino connectors.

 

[peter halle]

In this video Peter talks about the need for a second domino for anti rotation at around the 4:00 Minute mark:



Peter

 

[Birdhunter]

I’ve used the 700 version of the connectors on a bed frame. Even tightened, rotation can occur. A traditional Domino tenon in parallel with the connector acts to prevent rotation.

Is there enough room on your rails for a connector and a dowel? The connector draws the parts together and the dowel prevents rotation. Even a 1/4” dowel should suffice.

Another possibility would be to use the connector centered on the rail and attach something on the leg behind the rail that would block rotation. I’m thinking of a small strip of wood glued to the leg. Even a 1/4” strip would be enough.

 

[nvalinski]

Thanks Peter, that was the video that made me realize that they don't work on their own for an application like this.

[member=15289]Birdhunter[/member], that was certainly a thought, but I guess an 8mm domino has a width of ~0.82". In a 1.5" piece, there's only 0.43" left for space on the shoulders and in between the dowel and the connector. Round that to about 1/8" between the edge and both pieces and 1/8" in between the dowel and domino, that's probably not enough to have some strength. The board behind is maybe a good idea. Would have been nice if you could almost sink the fastener in a little further so that the matching one could nest in as well, but that would bring the hole in closer. I may end up swapping the sides that get assembled too, so that the panel insert on the side prevents rotation.

 

[Cheese]

Have you considered using 1/8” steel/stainless dowels? They’re commonly available in lengths up to 2”. They’d work well if the material is maple or oak.

 

[Birdhunter]

I think that if I were doing this, I’d go with a single Festool connector in the rail and some form of rotational blocker external to the rail.