Using A New Dado Technique...New To Me...

[Derek Arita]

OK...So I was trying to figure out a different way to do some dados, other than on the TS. I liked some of the jigs I've seen, but didn't want to buy another jig. I already have a Festool OF1400 and guide rail, so I figured out a way to do the same thing that jigs do, without the jig. The technique can be done with other routers using guide rails. I'm sure a lot of you have already figured this out, but this is new to me, so I thought I'd share...
I set up the router as usual, using the router "Guide Rail Stop", which is Festool's name for the router guide rail adapter. Since I'm using a 1/2" upcut bit for a 3/4" dado, I use a 1/2" gauge block to space the router exactly 1/2" from the rail edge.
http://imageshack.us/a/img189/2222/img0610cx.jpg
http://imageshack.us/a/img217/2565/img0611lp.jpg
I then run the first pass. For the second pass, I replace the gauge block with a piece of the actual material that's going to fit into the dado, along with a .008" feeler gauge piece, for glue spacing and plywood imperfections.
http://imageshack.us/a/img145/6910/img0614z.jpg
http://img5.imageshack.us/img5/5953/img0612wc.jpg (http://imageshack.us/photo/my-images/5/img0612wc.jpg/)
After making the second pass, I get a dado that is consistently just the right size for that piece of plywood.
http://imageshack.us/a/img829/4439/img0615hm.jpg
Comments?

[Matt Meiser]

Like!

Cool idea. Beats hoping your bit is "close enough."

[Bobby O'Neal]

I haven't seen it exactly this way. Cool stuff

[Matt Meiser]

So how do you set the exact position of the rail to get the dado where you want?

[Bill Huber]

That is cool, that is working just like the Accurate Guide did when it was out there.

You can use the same method to make sliding dovetails.

[Derek Arita]

So how do you set the exact position of the rail to get the dado where you want?

I did a test cut and measured the distance, 3 3/16", from rail edge to dado edge. That will remain constant for me as long as I use the same equipment. Of course, that 3 3/16" is very particular to my setup, so yours will be different, I'm sure.
As for sliding dovetails, I don't know for sure, but I think it should work the same. All I can say is, give it a try...I'd love to know too. And yes, the Accurate Guide was part of my inspiration. I can see this adapted to other sliding router/rail setups. You could even use a straight edge and a couple of sheets of hardboard to make this work.

[Jamie Buxton]

I don't understand how the guide rail adaptor works. I'm seeing the two rods coming out of the router, and they run through two black plastic things which are hooked on to ridges on the guide extrusion. I'm seeing what looks like a micro-adjuster wheel -- the green thing -- which would tweak the distance between the two black plastic things. However, the distance between the two black plastic things is already set by the guide. So the microadjuster can't do anything. Why does Festool put it there?

[Erik Christensen]

man that is very clever - thanks for the great tip

[Jeff Monson]

I don't understand how the guide rail adaptor works. I'm seeing the two rods coming out of the router, and they run through two black plastic things which are hooked on to ridges on the guide extrusion. I'm seeing what looks like a micro-adjuster wheel -- the green thing -- which would tweak the distance between the two black plastic things. However, the distance between the two black plastic things is already set by the guide. So the microadjuster can't do anything. Why does Festool put it there?


The micro-adjuster lets you fine tune the distance from the router to the guide rail. You would have to see a photo of the underside to get mechanics of it, but it works.

[Derek Arita]

I don't understand how the guide rail adaptor works. I'm seeing the two rods coming out of the router, and they run through two black plastic things which are hooked on to ridges on the guide extrusion. I'm seeing what looks like a micro-adjuster wheel -- the green thing -- which would tweak the distance between the two black plastic things. However, the distance between the two black plastic things is already set by the guide. So the microadjuster can't do anything. Why does Festool put it there?

Normally, only one of the black things is on a rail, the other floats free and can be adjusted by the green wheel thing. In this case, I put both on rails just for added stability...the adjuster does nothing.

[Michael Mayo]

And how do you get the rail square to your intended cut line? How does the spacer and feeler gauge stay put when moving the router while cutting the dado? Looks like a great solution!

[Steven J Corpstein]

Or you could invest and go this route. With this setup, you eliminate having to use a spacer and can dial in the dado position within .001".252938

[Derek Arita]

And how do you get the rail square to your intended cut line? How does the spacer and feeler gauge stay put when moving the router while cutting the dado? Looks like a great solution!

From a reply above...
"I did a test cut and measured the distance, 3 3/16", from rail edge to dado edge. That will remain constant for me as long as I use the same equipment. Of course, that 3 3/16" is very particular to my setup, so yours will be different, I'm sure.
As for sliding dovetails, I don't know for sure, but I think it should work the same. All I can say is, give it a try...I'd love to know too. And yes, the Accurate Guide was part of my inspiration. I can see this adapted to other sliding router/rail setups. You could even use a straight edge and a couple of sheets of hardboard to make this work."
In answer to, "And how do you get the rail square to your intended cut line? How does the spacer and feeler gauge stay put when moving the router while cutting the dado?" I measure for the dado, but I guess you could use your MFT guide as well. Once the router is locked down on the rods, I remove the spacer and feeler gauge.

[Gary Herrmann]

Yet another reason to keep asking the boss for Festools.


Hey, at least I have a hat...

[Brian Kincaid]

Nice setup! The only downfall I see is that the adjustments would have to be made every time you wanted to move the rail.

Here is an instruction video for a simlar jig (EZ)
http://www.youtube.com/watch?v=_Go6RdfL288
Or youtube search 'EZ SRK Dado Setup'
They have a new router carriage that works the same way.
The idea is:
1) Set up the stops for the size of the material
2) Remove the size of the bit
3) Make repeat cuts using the stops, move the rail and the stops stay in position.

-Brian

[Derek Arita]

EZ SRK looks great, but then I'd have to buy the rail and the SRK...right? I wanted to try and use what I had. Lot's of great jigs out there for doing this. You just made me think of something...a way to do just what you're talking about. Thanks!

[Brian Kincaid]

...You just made me think of something...a way to do just what you're talking about. Thanks!

Cool! Be sure so post your new idea! I'm very DIY where it makes sense. If you can modify a jig you already have why not?

-Brian

[Todd Brewer]

Or you could invest and go this route. With this setup, you eliminate having to use a spacer and can dial in the dado position within .001".252938

And your route is...? Not enough information...

[Derek Arita]

Or you could invest and go this route. With this setup, you eliminate having to use a spacer and can dial in the dado position within .001".252938

Again...lots of neat jigs out there...didn't want to have to buy one to do these dados. I wanted to figure out a way to do precise, tight dados without a specific jig.

[Sam Murdoch]

Again...lots of neat jigs out there...didn't want to have to buy one to do these dados. I wanted to figure out a way to do precise, tight dados without a specific jig.


This is my non Festool way - http://www.sawmillcreek.org/showthread.php?198249-Bookcase-Joinery-Simple-Method-Secure-Joints Though I do use the Festool too, using Steven's method in post # 12 in this thread. I think the sled is more foolproof though.