Dovetail jig too tight
I have reviewed this post https://www.finewoodworking.com/forum/porter-cable-dovetail-jig-problem
and still struggle with my half blind dovetails being way too tight.
I come from a hand tool background and can cut half blind dovetails with a fine toothed saw and chisel no problem. I am new to using router jigs though.
I have the PORTER-CABLE PORTER-CABLE 4216 Super Jig and am using the provided dovetail router bit and template. I have 12mm plywood I am trying to join via half blind dovetails. I followed the instructions, however the pins are so tight that I cannot even hammer it in. So I decreased the depth of cut of the router, eventually it fits but the dimension of my dovetail is then off. Meaning the piece left over on the front of the drawer is very thick.
So my question is – how do I control the thickness of the “blind” part of the pin board? Or is this predetermined by the jig and router bit used?
I'll start by saying I love that jig. but it can be a bit finicky and my biggest complaint is that there are a few things in the instructions that should be printed in big bold letters and highlighted in yellow. I know you read the instructions, but read them again. Including the part about initial set up of the jig. If your depth gauge isn't set right it can throw off your cuts. Mine is set for imperial, if yours instructions are in metric, the rounding may be your culprit. Also try putting a pencil line on the jig in the groove used to line up the jig front to back. I find it hard to see the groove and get the alignment just right. Look at all the simple stuff that is easy to get wrong; correct bit (the straight one), jig facing the right way, correct bushing, etc. Other than all that, it's all about practice and test cuts. Good luck, IMHO the results are worth the effort.
Thanks for your thoughts. Sadly I followed all those steps precisely. My depth of cut is about 1mm less than the 3/8” mentioned in the book as that was too tight. But alas… regardless of my depth of cut on my router bit it always is just way too tight. The only way I can make it fit is spending 1 hour per dovetail and a chisel which is pointless.
The problem for me is that changing the depth of cut on the router bit does nothing for how tight or loose the fit is, only how thick the blind part of the pin board is, when cutting once. Only if I cut the dovetails at say 3/8” depth, then recut them all at 1mm less do they begin to fit. I was hoping I did not need to cut all my dovetails twice to get them to fit. By then it is faster to do them by hand.
What am I missing?
So I took some scraps and repeatedly tried to cut half blind dovetails on a 3 1/4" wide piece of plywood, 1/2" thick. I started at the recommended depth of 3/8". I measured the tails and pins with a vernier calliper. The tails were 4.00mm; the gaps in the pin board were 3.30mm across - clearly the reason they do not fit.
I tried again and again, decreasing the cut depth. Only when I reached 2/8" did it work. The fit was tight but good. That seems like an awful long way from 3/8". I am using the correct dovetail cutter (17/32", 7 degree) and template guide (3/4" OD).
I also repeated the centering of the base plate on my router. It was not out and I confirmed it is still good.
So is this normal?
Definitely not normal. Mine go together by hand, sometimes a tap with the heel of my hand. But rarely do I need to tap with a dead blow or anything. I teach the class using this jig at the local Woodcraft store. Usually it's something very simple like having pin and tails boards reversed or using the wrong height gauge and you are just searching for your "Duh Moment". Sometimes it helps to have somebody else watch. Sometimes it helps to set it aside for a week or so and start over with fresh eyes. i wish i had something better for you, but without being able to see what you are doing, I got nothing. Sorry.
If I make a short video of what I am doing would you try to help me?
I am having a similar problem. Was there ever a resolution to this issues?