Novice at dovetail joints. What do adjust to get the perfect fit?

[David Tolsky]

I have a Porter Cable dovetail jig and router. I'm at the stage where I'm ready to cut the dovetail joints on my boxes. The sides of my red oak boxes are 1/2" thick. I'm making 4 boxes at a time and I can't mess them up so I made 4 extra boards of the same thickness to make practice cuts on. So far, I've made 2 passes. The first pass did not cut deep enough into the horizontal piece and the pins stuck out a lot. The second pass, the cuts were deeper into the horizontal piece so the pins fit in better but still stuck out a little and the joint was not tight fitting.
Is there a rule of thumb to get a perfect fit on dovetail joints? My stock is 1/2" thick as mentioned. Is there an article on this or a youtube video and how to cut perfect dt joints? Thanks

[Lee Schierer]

You have to adjust the depth of cut to get the fit you want. What I do is once I figure out the best setting for my dovetail jig I accurately measure the height of the bit from the router base and record that dimension for a given thickness of stock. Then the next time I need to make dovetails, I have a good starting point and only need to adjust a few thousandths up or down to get the fit I want.

With respect to the router base plate, you need to "heighten to tighten" or "Lower to loosen".

[Earl McLain]

When i was using that jig, i had trouble getting proper light to the little pad used to set the bit depth. So, i started scribing a line the thickness of my stock on a piece, which i then mounted vertically on the jig. Set the bit depth to the scribe line, started getting real close if not right on on the first try once i started doing that. Was much easier to see the depth of cut for me.

earl

[David Tolsky]

My jig is a bit older and does not have a bit depth gauge on the side. What is the best way for gauging correct bit depth? I

[Martin Wasner]

My jig is a bit older and does not have a bit depth gauge on the side. What is the best way for gauging correct bit depth? I

How the joint fits. You have to make test cuts to get the fit to determine the depth.

[David Tolsky]

Ok thanks e

[Al Launier]

Good topic David. I have a brand new PC 4216 dovetail jig I received for Christmas a few years ago that I've never "gotten around" to using. Your post brought up a question that resulted in answers that will be helpful - if I ever get to use this jig.

[George Bokros]

When i was using that jig, i had trouble getting proper light to the little pad used to set the bit depth. So, i started scribing a line the thickness of my stock on a piece, which i then mounted vertically on the jig. Set the bit depth to the scribe line, started getting real close if not right on on the first try once i started doing that. Was much easier to see the depth of cut for me.

earl

Ed can you expand on this a little. It could also help me and I am having a little trouble following what you said.

Just figured it out.

[David Tolsky]

Al it's a lot of fun to use once you get the hang of it. For me it might be a little more trial and error than most but it is rewarding when the pins fit into the tails like a glove.

[David Tolsky]

Al it's a lot of fun to use once you get the hang of it. For me it might be a little more trial and error than most but it is rewarding when the pins fit into the tails like a glove.

Ok so is bit depth generally equal to the thickness of the stock being cut?

[Doug Hepler]

David,

Since you wrote that your jig is an older one, I'm guessing that you did not get the rather extensive manual that comes with the jig. Possibly, yours is also missing a few parts(?) In any case, unless you feel that it spoils the fun to read a manual, you will find it very useful. You can find one online. Rockler has a pdf online.

Doug

[David Tolsky]

David,

Since you wrote that your jig is an older one, I'm guessing that you did not get the rather extensive manual that comes with the jig. Possibly, yours is also missing a few parts(?) In any case, unless you feel that it spoils the fun to read a manual, you will find it very useful. You can find one online. Rockler has a pdf online.

Doug

It is possible that there are some parts missing but I don't think so. I've seen the relatively new PC jig that has the big levers for clamping down on the stock. Mine does not have the levers and I don't think it has any type of depth stop anywhere. I am going to go with a little less depth on the bit as I think I will be more in the ball park. I'll also look online as I don't know if I still have the manual laying around somewhere. As the rest of my tools that have finally come out of my storage locker after 8 years, I am jumping back into woodworking as fast as I can. Divorce had forced me into an apartment where I lived without woodworking for that long and I really missed it. I'm blessed to have a new start now and my shop has been rebuilt. I'll be asking a lot more questions...

[Earl McLain]

Sure George--since the cut needs to be the as deep (or a few thou over) as the thickness of the stock, i use the actual stock thickness to scribe a board--usually a piece of the project stock. After the rest of the set-up is done, i mount it vertically in the jig--as if it were going to be cut with pins or tails. Set the router on the template, then raise or lower the bit to the scribe line. Still run a test cut, but usually if i had to make any adjustment, it's very minor.

The new versions of the jig have a little pad under the left end of the template to set the proper depth, but it's black and in a shadowy area for me to see. Scribing was faster, and more accurate as far as i was concerned. I suppose one that instead of scribing one could use a piece of stock thickness (like the backer used to set the template height) and use the horizontal as a depth guide--but i found that almost as hard as using the little depth gauge.

earl

[Doug Hepler]

David,

Oh, you meant OLDER older. Mine is a few years old, and I was not aware that the design had changed that much/ Evidently it has if yours does not have the cam clamps. That might mean that I don't know anything that would help you.(Gallic shrug) Have a look at the current manual anyway, who knows? It does discuss how to tighten/loosen half blind dovetails.

Welcome back to WW and to this forum. I'm an occasional visitor but IMO the quality of discourse here is usually pretty good, compared to some others.

Doug