Porter Cable 4215 Mini Dovetail Template

[Doug Hepler]

HI

This post is deep in the weeds, for folks that have experience making half blind DT with the PC jig and 4215 mini template.

I have a bunch of shop drawers to make so I thought that it would be fun to try the 4215 mini dovetail template on my 4200 series DT Jig. It wasn't fun.

The joint wouldn't close completely. When the DT fit well, there was a gap between the boards, that is, the DT were about 1/16" too long or the sockets in the pinboard were about 1/16" too shallow. The manual says that I should extend the depth of cut to correct this. I did that, in about 1/32" increments (one revolution on the depth gauge). As the depth of cut increased, the joint got tighter and tighter just like the manual said it would. Finally, when the gap had disappeared the joint was so tight that I couldn't assemble it.

The work-around I found is to cut a reasonably snug joint and then trim the DT to make them shorter or to put a spacer between the template and the tail board before cutting. This seems like a kludge. When you set the tail and pin boards in the jig they line up and the DT bit should cut them to a precise matching depth but that does not happen when I do it. I suppose I must be doing something wrong, but I cannot think of what it would be. Also, I found a post on Lumberjocks from a guy that had a similar problem.

So -- if you have had success cutting half-blind DT with the 4215 mini template please let me know that, and how you did it.

Doug

[Cary Falk]

Doug,
I used to have the PC and the mini DT template. I used it once to make some small jewelry draws. That was probably 10 years ago. I don't remember any struggle to get them right. Setup was not any different then the standard DT. I know that doesn't help you with your current problem. I would go out and make a couple if I still had the jig.
Cary

[Doug Hepler]

Hi, Cary

I have confidence in the PC jig, and your post is encouraging enough for me to try again. Maybe the necessary precision for depth of cut is less than 1/32". My plan now is to shorten the depth of cut until I get snug joints I can assemble. If the DT still seem too long I will use my workaround to shorten them. I'd like to see if this is a practical means of cutting miniature half-blind DT but frankly, even hand cut DT or lock miter joints would have been much quicker (so far).

Thanks

Doug

[Dave Anthony]

I have this jig, and my experience has been it's very sensitive to depth of cut. I suspect a precision granularity of 1/32" is too coarse. Once I get a test cut that's perfect, I save the test pieces and use them to set the router depth the next time (I've had mixed results using the depth measurement setup on the jig, it flexes too much).

[Doug Hepler]

Thanks Dave & Cary. I'm going to tweak it some more and see what I can accomplish

Doug

[Doug Hepler]

OK, just for the record. (I don't suppose this will ever be interesting to most people but I'll finish this thread.) I have adjusted the depth of cut by quarter turns (1/128") and less. By trial and error I got a joint that I could assemble (barely) after the PVA was applied. The joint would not quite close, because the DT were about 1/32" too long. I worked around that by spacing the tail board 1/32" below the template before locking it in place or by trimming the ends of the DT. I still do not understand the cause of this problem.

Although I am happy with this jig to make normal sized half-blind joints, through DT and box joints I don't expect to use this setup again with the miniature template and bit to make half-blind. Almost any other joinery method would be preferable.

Doug