# DT Bit Setup Blocks



## RoyBullets (May 26, 2008)

Spent some more time in the garage tweaking the fit for my HB dovetails and I got the 17/32" bit where I want it on the Porter Cable jig. The depth guide works pretty well on the jig but I wanted a better setup up block. After a little trial and error I came up with a block in the attached photos (sorry for the blurry photos).

Since this jig uses a guide bushing I ended up taking a forstner bit and cutting slightly off the edge of a small block just deep enough to clear the bushing. Then I clamped the block in the vise and ran the router over the top. Not super elegant or pretty but worked really well when I re-setup the cut again.

Just wondering what others do for setup blocks? I saw a picture of one that uses a screw similar to what I do with a stop block on my table saw but that had the same problem as the depth guide in that the bit is never really flat.

Thanks.


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## BowlBit (Nov 2, 2009)

I have scrap pieces of 1/4", 1/2" and 3/4" Corian. I just glue them up for what I need, using exopy, and then cut up what I need. Pretty much the same as what you did, but I found over the years, they can take quite a bit of abuse. I also use Magic Markers to color code the edges for set ups.


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## jlord (Nov 16, 2009)

That same setup block for half-blind dovetails will work for material thickness's of 1/2" to 1-1/8" as the joint is referenced from the inside. Once you've found your sweet spot you can use that same setup & the joint will all fit the same.


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## RoyBullets (May 26, 2008)

jlord said:


> That same setup block for half-blind dovetails will work for material thickness's of 1/2" to 1-1/8" as the joint is referenced from the inside. Once you've found your sweet spot you can use that same setup & the joint will all fit the same.


I thought that was the case but the manual was not really clear on this point and have not had a chance to try on other stock.

With this roughly 3/8" depth of cut it is half the thickness of the 3/4" board so it looks nice. If I use this same depth on say 1/2" stock, will the DT still look as nice or do I not really have a choice due to the sweet spot?

Here is what my test joint is looking like (sorry again for my crummy camera)

Thanks for the help.


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## jlord (Nov 16, 2009)

Once you have your sweet spot it will not matter the thickness of your material as it is machined from the inside of the joint. Here is a pic of a blind-dovetail on 5/8" material. The only measurement that will change is the amount of material on the outside of your joint (face of the drawer or box), but you do not need to change your setting as it will not matter. Theses were done on the same PC jig as yours.


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## RoyBullets (May 26, 2008)

jlord said:


> Once you have your sweet spot it will not matter the thickness of your material as it is machined from the inside of the joint. Here is a pic of a blind-dovetail on 5/8" material. The only measurement that will change is the amount of material on the outside of your joint (face of the drawer or box), but you do not need to change your setting as it will not matter. Theses were done on the same PC jig as yours.


Awesome work! 

Thanks for the confirmation. I am going to work on the Mini HB setup next but I need to pick up some thinner stock.

I appreciate the help.


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## jlord (Nov 16, 2009)

RoyBullets said:


> Awesome work!
> 
> Thanks for the confirmation. I am going to work on the Mini HB setup next but I need to pick up some thinner stock.
> 
> I appreciate the help.


Thanks,
The mini will use different setting & measurement width of stock to center your joints with 1/2 pins top & bottom. But still one sweet spot.


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## allthunbs (Jun 22, 2008)

Hi James:



jlord said:


> Once you have your sweet spot it will not matter the thickness of your material as it is machined from the inside of the joint. Here is a pic of a blind-dovetail on 5/8" material. The only measurement that will change is the amount of material on the outside of your joint (face of the drawer or box), but you do not need to change your setting as it will not matter. Theses were done on the same PC jig as yours.


Thanks. This bears repeating. In essence what you're saying is that "sweet spot" changes only when the pin size changes, not the thickness of the material or how far the sockets are cut. Therefore, setup for dovetails entails a lot of trial and error until you find that sweet spot. From then on, you're sailing, but until then, you're tearing your hair out.


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## jlord (Nov 16, 2009)

allthunbs said:


> Hi James:
> 
> 
> 
> Thanks. This bears repeating. In essence what you're saying is that "sweet spot" changes only when the pin size changes, not the thickness of the material or how far the sockets are cut. Therefore, setup for dovetails entails a lot of trial and error until you find that sweet spot. From then on, you're sailing, but until then, you're tearing your hair out.


Yes that's true. For half-blind dovetails using the stock bit that comes with the jig (17/32" - 7º) a close setting will be 5/8" depth the base of the router (1/4" template thickness, 3/8 cutting depth = 5/8"total) that should be in ballpark. Some like their joints to fit tighter or looser then the next guy also considering glue or no glue in joint. The same setting will fit the same in stock thickness of 1/2" to 1-1/8" as all machining is done from the inside of the joint. Thinner than 1/2" you should use the small template. Through dovetails the bit is set for each thickness but blind dovetails will use same setup.

Using this bit in the PC jig will also determine your drawer sizing as the PC uses 1" increments for the larger template (some other jigs use 7/8" increments). It goes by 1" + 1/4" so your drawer or box heights will be 2-1/4", 3-1/4", 4-1/4" etc to end up with even half pins top & bottom. 

In the pics I have a 5" opening in top drawers & used a 4-1/4" height for drawer parts. With the under mount slides this leaves very little gap on top for clearance. If using side mount slides I would have more room as I could drop the drawer down.


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## RoyBullets (May 26, 2008)

jlord said:


> Yes that's true. For half-blind dovetails using the stock bit that comes with the jig (17/32" - 7º) a close setting will be 5/8" depth the base of the router (1/4" template thickness, 3/8 cutting depth = 5/8"total) that should be in ballpark. Some like their joints to fit tighter or looser then the next guy also considering glue or no glue in joint. The same setting will fit the same in stock thickness of 1/2" to 1-1/8" as all machining is done from the inside of the joint. Thinner than 1/2" you should use the small template. Through dovetails the bit is set for each thickness but blind dovetails will use same setup.
> 
> Using this bit in the PC jig will also determine your drawer sizing as the PC uses 1" increments for the larger template (some other jigs use 7/8" increments). It goes by 1" + 1/4" so your drawer or box heights will be 2-1/4", 3-1/4", 4-1/4" etc to end up with even half pins top & bottom.
> 
> In the pics I have a 5" opening in top drawers & used a 4-1/4" height for drawer parts. With the under mount slides this leaves very little gap on top for clearance. If using side mount slides I would have more room as I could drop the drawer down.


Thanks for all the detail. It is great to hear first hand experience after reading through all the manuals.

I was hoping to get a couple of boxes built today but the tropical strom blew in and dashed my plans. Back to planning and not doing for today


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## dutchman 46 (May 23, 2007)

Very nice job on the dovetails James! I could do nothing at all to improve those. I don't think there is anyone that can find an imperfection on those. Super


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