Incra Jig / Dovetailing Question

[Jeff Wright]

I have an Incra Jig with all its fences and want to cut some dovetails in some drawers I'm making. I will use through dovetails at each corner (the front will have an applied face since I will be using Blum undermount slides).

Question: The Incra manual says to FIRST determine the bit depth of cut from the chosen template. THEN, plane the drawer sides to that thickness. It explicitly says to NOT first cut the pieces to a thickness and then raise the bit to that height. But I want to use 5/8 inch thick drawer sides and the Incra manual shows NO templates using that thickness . . . they are all 1/4, 1/2, 3/4, etc.

Why can't I simply dimension my drawer sides to my desired 5/8 inch thick and raise the router bit to match that dimension?

[Jason Beam]

Because the spacing on the templates is for a given depth of cut. If you cut deeper, the indexes may have to be moved further apart or closer together to land in the right spots for clearing out the other half of the joint. Since one side is done vertical and the other is done laying flat, being consistent is a bit more critical.

[Dewey Torres]

Jeff,
One thing you can do is lay out your increments without the template. It will require a bit of time and layout but once done you can just reference your sliding rule for perfect spacing.

I might also PM Bill Wyko if I were you! Heck, he has projects on the INCRA website.

[Jeff Wright]

I called Incra with my question and their technical department suggested I try a simple Excel spreadsheet they have that allows you to input your router bit geometry (diameter, etc) and it solves for either depth of cut or cut spacing. You can then either select one of Incra's provided scales to match the spreadsheet's answer, or create your own template. Pretty cool and it's free!

[Dewey Torres]

Jeff,
Can you post the file here? I want it too.

[Myk Rian]

Yes, please post the file or a link to it.

[Greg Hines, MD]

I would be interested in that spreadsheet too.

Doc

[Jeff Wright]

Send me an email and I will send it to you by personal email. My email is jkwright60 @ gmail.com (without the spaces). I didn't ask for (or receive) permission to post publicly and I don't want to raise the ire of Incra.

[Gary Muto]

I sent an email for the info as well. Thanks in advance.

[Mike Thomas]

Thanks Jeff. I too will be interested in the spreadsheet and will follow with an email. BTW, I have been using my INCRA TSLS set up to do through dovetails in 5/8 maple drawer boxes for some time now. I was able to get it done by trial and error the first time and then with a set of set up blocks from there on.

[Brent Ring]

Thanks Jeff. I too will be interested in the spreadsheet and will follow with an email. BTW, I have been using my INCRA TSLS set up to do through dovetails in 5/8 maple drawer boxes for some time now. I was able to get it done by trial and error the first time and then with a set of set up blocks from there on.


This was my experience as well. I used it for some christmas serving trays I built this year, and loved the joints it produced. I have the INCRA Ultralite System and it has been perfect for the drawers and boxes I have built. I have done box joints, and both half-blinds and thru dovetails. I like it! I have also sent a private email for the spreadsheet.

[Jeff Wright]

Thanks Jeff. I too will be interested in the spreadsheet and will follow with an email. BTW, I have been using my INCRA TSLS set up to do through dovetails in 5/8 maple drawer boxes for some time now. I was able to get it done by trial and error the first time and then with a set of set up blocks from there on.

Curious if you recall what you used for spacing if you used the 5/8 inch 7-degree dovetail bit. The incra spreadsheet calculates it to be 1.097 inches which is one inch and 3 32nds. How would you handle the fact that there is no precise mid-point for that spacing?

[Mike Thomas]

Curious if you recall what you used for spacing if you used the 5/8 inch 7-degree dovetail bit. The incra spreadsheet calculates it to be 1.097 inches which is one inch and 3 32nds. How would you handle the fact that there is no precise mid-point for that spacing?
Jeff, I am writing this from my hotel room on the road, that work thing you know. I don't remember which dovetail bit I used but can check when I get home and let you know. As far as the mid-point I use the INCRA method in the manual. From my experience it is very critical that this be done precisely.

[Jeff Wright]

Jeff, I am writing this from my hotel room on the road, that work thing you know. I don't remember which dovetail bit I used but can check when I get home and let you know. As far as the mid-point I use the INCRA method in the manual. From my experience it is very critical that this be done precisely.

Thanks Mike. I, too, at one time spent a lot of time on the road (and in the air). My wife says one year I was in 43 states. I used to fly three times a week. Made for a tired fellow coming home on a Friday night. I used to visualize my arms stretched from carrying luggage and a computer as I dragged both along the airport terminal floor. Travel safe.

[Ralph Barhorst]

Jeff,

Download this file. It might help, but I think that it only does half-blind dovetails.

http://www.internetwoodworking.com/w5/dovetail.html

[Jeff Wright]

Jeff,

Download this file. It might help, but I think that it only does half-blind dovetails.

http://www.internetwoodworking.com/w5/dovetail.html

Ralph . . . thanks. Yes, I did have that file and I agree . . . it appears to only output templates for doing half-blind joints.