DT Sizes on D4R

[Burt Alcantara]

I'm giving thought to the D4R. I have a number of cabinet projects for the house that will entail a number of blind dovetails. After these are built, the main use of this jig would be for small boxes.

One of the big attractions for me is the variable joinery pin/tail sizes on a single board. What I don't know is how many or how small can they be.

How many dovetails could I fit into a board that is 2" wide? I'm not looking for the world record, but good solid joints.

Also, when making joints, does one need a backer board?

Thanks,
Burt

[Jim Becker]

Here are the charts posted on the Leigh Industries site that details cutter and dovetail sizes.

Through Dovetails:

http://www.leighjigs.com/images/TD_BitChart_Web1.gif

Half Blind Dovetails:

http://www.leighjigs.com/images/HB_BitChart_small.gif

BTW, you don't need a LOT of dovetails to facilitate a strong joint. One of the advantages of a variable spacing jig like the D4 and D4R is that you can us less dovetails on a joint... ;)

[Burt Alcantara]

Jim,
Great chart. The reason I've stated maximum joints is purely decorative. For small boxes, glue would probably be plenty strong.

Thanks for great info!
Burt

[Jim McFarland]

<snip>
Also, when making joints, does one need a backer board?

Thanks,
Burt

I cut 25+ end-to-end dovetails on walnut a few months back and had chip-out on 3 of the 50+ cuts. I had to trim and use a backer board in those few instances. In this application, trimming the bad joint and re-cutting wasn't a problem -- if I was making the last cut on a expensive drawer side I would use a backer/front board just to be safe. Also be sure to follow the tips in the Leigh manual re minimizing chip-outs. 1/4" MDF is a cheap backer board IME (although may be a bit abrasive on the router bits over time).