# Dovetail jig question: please mansplain me



## nickbatz (Mar 7, 2018)

I just made my first dovetailed drawers. Half-blind dovetails.

The test joint, using douglas fir, was fine, but then the real walnut and oak joint was too tight - meaning I had to do too much work with the mallet to get it to sit. Yes, I get why, and it came out great after sanding.

But I'm confused. The jig and its instructions tell you to retract the bit and/or adjust the stop so you make shallower pins to loosen the joint.

Say what?

The pins needed to be longer. So that doesn't make sense.

And - here's the part I really need mansplaining about - how does retracting the bit make the joint looser? Is it just because the tails don't fit in as far? Or is it because the fatter part of the bit's cone is higher up?

This is the jig, by the way. Other than that the included bit is total ********************e (I bought a better one), I'm happy with it and am surprised at how easy it is to use:

https://generaltools.com/e-z-pro-dovetailer-ii-dovetail-jig

I also have a new old stock Leigh jig that I haven't used yet, but I got it for larger things. It only does through dovetails, but it's a lot more solid.


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## Loren (May 30, 2008)

With half blind dovetails with an equal spaced jig it can be easy to get pins and tails mixed up. Perhaps you're doing that or perhaps the person who wrote the instructions got turned around themselves.


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## nickbatz (Mar 7, 2018)

I think so!

On this jig it cuts tails with rounded fronts.

It's the pins adjustments that are confusing my brain.


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## RichT (Oct 14, 2016)

> On this jig it cuts tails with rounded fronts.
> 
> - nickbatz


The pin board goes horizontal and the tail board vertical. There's nothing to get mixed up.

Half-blind tails are rounded. That's how they fit into the pin boards which have rounded cuts by virtue of the dovetail bit being round. The depth is equal for both boards due to the fact that both are flush to the template, and changing the depth to affect the joint tightness will change the cut depth in both, equaling them out. The depth of the inset of the tail board into the pin board is controlled by moving the template forward and backward. Its setting will depend on the thickness of the tail board.

Once you have the cut depth dialed in, it won't change for different board thicknesses. Only the front-to-back position of the template would change if you used a different thickness tail board.

I made a simple jig for setting the depth of the router bit.


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## 1thumb (Jun 30, 2012)

Whats a good idiot proof dovetail jig for a potential idiot to purchase and use? Asking for a friend


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## SMP (Aug 29, 2018)

If its any consolation i had that same jig and ended up selling it on ebay cause I couldn't get consistent results with it. Maybe i didn't break through the learning curve for it, but i ended up frustrated more times than not.


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## RichT (Oct 14, 2016)

> If its any consolation i had that same jig and ended up selling it on ebay cause I couldn't get consistent results with it. Maybe i didn't break through the learning curve for it, but i ended up frustrated more times than not.
> 
> - SMP


It's a strange one for sure. I was picturing one of the Porter Cable 4200 series type of jigs, since that's what most clones are based on. That's what I meant by the tail board being vertical and the pin board horizontal, since they're mounted that way in the jig and both are cut in one pass.

If all you want to do is half-blind dovetails, the PC 4210 will do the job nicely. It's super easy to set up and get repeatable results with.


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## nickbatz (Mar 7, 2018)

Rich, the results I got are remarkably consistent, and the drawers look awesome. The jig works well, and I've never cut dovetails before.

If anyone had inconsistent results, dollars to donuts it was because of that criminally lousy bit that comes with it. I replaced that right away.

Walnut fronts and oak sides. Gorgeous!

What confuses me is the adjustable stop that shortens the depth of the pins - and doubles as a bit depth gauge - being labeled… what seems backward.

I'd just like it to fit together a little more easily, but I was able to bang it in there with enough room for the glue.


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## Arcola60 (Nov 16, 2011)

When I first bought mine I didn't use the height gauge built into the machine. I used an adjustable parallel. I had one. It was dead on the first time. I also used it to set the depth of the router bit. No tweeking needed to get consistent results.

Ellery Becnel


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## LittleBlackDuck (Feb 26, 2016)

*batzy*, let me make an offering out of left field…

While I appreciate you are not using a *Leigh D4R* jig, *Leigh* instruction manuals are recognised as a cut above the rest.

Maybe looking at *Chapter 8 Through Dovetails* in their manual 








may clear up some of the confusion… looks heavy but actually make sense and is quite thorough… good detail in how to fix issues.


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## nickbatz (Mar 7, 2018)

That makes sense, LBD. Thanks.

I was thinking of the pins as sockets and the tails as pins - which is what they are with a half-blind dovetail joint.

Those instructions explain it by saying deeper pin cuts remove more wood between pins. Okay.


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## nickbatz (Mar 7, 2018)

And those instructions are a lot more detailed than the ones for my old Leigh jig!

But I'm going to use it for large pieces, as I said. The General Tools one is fine for drawers, and simpler (since there are no bit changes).


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## RichT (Oct 14, 2016)

> The General Tools one is fine for drawers, and simpler (since there are no bit changes).
> 
> - nickbatz


There are no bit changes when doing half-blind dovetails using the Leigh or the Porter Cable jigs. The Porter Cable can do both boards in one pass. So can a Leigh if it's been upgraded for that ability.


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## nickbatz (Mar 7, 2018)

> There are no bit changes when doing half-blind dovetails using the Leigh or the Porter Cable jigs. The Porter Cable can do both boards in one pass. So can a Leigh if it s been upgraded for that ability.
> 
> - Rich


My Leigh jig isn't * the * Leigh, it's a new old-stock one that uses goldenrod cardboard shims and only does through dovetails. But it accommodates up to 18" wide boards, which I need for the frame of the custom desks I make (if I'm going to dovetail them, and up until now I haven't).

TD-514L. https://leightools.com/wp-content/uploads/2017/04/TD514-instructions.pdf

But once again, I used the other one for these drawers. In addition to being simple to use, it happens to fit nicely into the middle of my Black & Decker Workmate - no fooling around with clamps on my bench, etc.


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