Centering Dominos

[jbasen]

I'm building a new dining room table and thought that it might be easier to use my Domino 700 for joining the cross members between the legs to the legs instead of cutting traditional mortises in the legs and tenons on the ends of the cross members.  But, I'd like the cross members to be perfectly centered where the attach to the legs and this is where I'm having an issue. 

With the traditional mortise and tenon method you simply cut your tenon on the end of the cross member and cut your mortise on the center of the leg. 

However, when I go to use the Domino to cut the mortises in the end of the cross member I run into a problem because the fence on the domino only adjusts to specific stops.  The stops won't allow me to perfectly center the mortise cuts on the end of the cross member.  So, to make sure my cross member is centered on my leg I believe I have to either:

1) Do the math to figure out how far off center on the cross member my mortises are cut and then offset the layout line on my leg this distance so I can line my Domino up and create offset mortises that match the offset on my cross members.

2) Create a custom shim for the fence that shifts the Domino so it is perfectly centered in the cross member

Either of these adds a bunch of extra work that is a bit fraught with the possibility for error.

Is there a better way or am I drinking to much green Kool-Aid and should just go back to traditional mortise and tenon joinery for this. 

Thanks

 

[Sparktrician]

You might want to take a look at Rick Christopherson's SCG-10 Self-Centering Guide. 

 

[jbasen]

You might want to take a look at Rick Christopherson's SCG-10 Self-Centering Guide.

Thanks for the idea.  Unfortunately it is the other direction I am having a problem with.  The dimensions of my cross members are, for example 1" x 4" and my leg is 3 1/2" wide.  The cross member will attach to the leg, for lack of a better term, vertically so the 1" height of the cross member is centered on the 3 1/2" width of the leg. The Domino then has to be centered on the 1" portion of the cross member.  To me, it looks like Rick's jig would allow me to center the Domino on the 4" portion of the cross member.

I hope this makes sense.  Some things just seem to be a bit hard to explain in a clear fashion.

 

[Sparktrician]

You might want to take a look at Rick Christopherson's SCG-10 Self-Centering Guide.

Thanks for the idea.  Unfortunately it is the other direction I am having a problem with.  The dimensions of my cross members are, for example 1" x 4" and my leg is 3 1/2" wide.  The cross member will attach to the leg, for lack of a better term, vertically so the 1" height of the cross member is centered on the 3 1/2" width of the leg. The Domino then has to be centered on the 1" portion of the cross member.  To me, it looks like Rick's jig would allow me to center the Domino on the 4" portion of the cross member.

I hope this makes sense.  Some things just seem to be a bit hard to explain in a clear fashion.

Got the picture now.  Just make yourself a clamping jig and set it back 10mm from the lateral axis of the domino.  The centerline of the domino bit is exactly 10mm from the baseplate bottom.  Does this make sense?

 

[ear3]

Just to clarify, you're talking about the depth adjustment on the fence?  Can't you just offset using the scale?  Meaning, once you've made the mortise in the cross-piece, you calculate how much a reveal you want on the leg, and factor that into the scale setting in milimeters.  You don't have to use the plastic step with the predetermined depth settings, btw.

 

[jbasen]

Just to clarify, you're talking about the depth adjustment on the fence?  Can't you just offset using the scale?  Meaning, once you've made the mortise in the cross-piece, you calculate how much a reveal you want on the leg, and factor that into the scale setting in milimeters.  You don't have to use the plastic step with the predetermined depth settings, btw.

Thanks.  I have always just used the stepped depth adjustment along with a set of the Seneca shims when setting the depth adjustment.  Until now that always met my needs for general cabinet construction.  It wasn't until I read your post and pulled my Domino out that I realized that you can pull the stepped depth adjuster out of the way and that the Domoino depth is really infinitely adjustable [doh]

All I need to do is mark a center line on my cross member, use that to line up the center mark on the side of the Domino, and lock the fence in.

THANKS!

 

[Rick Christopherson]

From the context of your question I get the impression you haven't seen the DF700 Supplemental Manual. That may have a few things in it to further help you out.

 

[jbasen]

Thanks Rick.  I've used the supplemental manuals for a number of Festool products but wasn't aware there was one for the DF700.  I'll definitely take a look.

Thanks again

 

[clark_fork]

I found this four part New Brit Workshop video (Table Project), absolutely essential for learning a method of joining legs to the apron. The principle is based on a reverse trim stop set with shims. One helpful tip is to make a template of the Domino plate and mark the center point of that template. Having a template the exact width of the plate helps with the setting up the shims and will give you a visual when attempting to set your center. One other tip is to make the leap and start measuring in metric. Learn the width of the plate and the base height of the guide, and handling things like centering is just a lot easier in metric. A tape is ok but I have better results with a metric folding rule.

This is  part 2 of four but it is the shim system. Understand that and you will be on your way to a faultless system on joining legs and the apron.



Good Luck

 

[grbmds]

If I understand the question the concern is about centering dominos within the thickness of the wood. If that is correct the dominos don't need to be exactly centered. Based on videos and other FOG posts I do not necessarily worry about this as long as the appropriate face of the wood is always referenced with Domino. If this isn't the issue, ignore me.

 

[jbasen]

Interesting video.  Thanks!