Thread: Alignment Problem With PC 4212 Jig

G'day All,
I would like to explain a problem I am having with the Porter Cable 4212 jig. I am now using my third template for the jig ( bought one and exchanged one ).
I noticed the problem doing through dovetails - the tails cut perfectly but after flipping the template around to cut the pins it is obvious that the pins workpiece does not align correctly. In other words the pins board is about 1/32 (or a little more) farther to the left than it should be ( or the template is further to the right than it should be ). This alignment makes the pin on the far right ( the last one cut ) slightly smaller than the others. So once the pins are cut the joint fits nicely but the board edges are not quite in line.
Of course I followed all the directions and triple checked everything - I do not want to waste anyone's time with this. I have spoken at length to PC tech support and others about this problem but no real solution. Here is a quick checklist ( to save time ):
1. the outside face of the board against jig for tails, away from it for pins, 2. left alignment bracket replaced with more recent version and checked for 90 deg and firmly against board, 3. all stock flat, straight and square, 4. the "forks" that hold the template onto the jig adjustment rods are installed on the template at about 90 deg but they are not spot-on but they measure out about the same distance from the edges of the template bottom, 5. the template goes down fairly smoothly over these rods and there is no movement from side to side after being pushed down.
Anyone can test the alignment by mounting and centering a board, say 2 1/4" wide and then setting the left bracket against it. Then flip the jig, remove the tails board and mount your pins board against the left bracket. Now instead of routing, just mark the end of the pins board along the lines of the template fingers. Of course these lines are not where the cuts would be because of the guide bushing but the lines will show the relative positioning of the pins. Now remove the pins board and, with the outside of the board still facing you, measure the distance from the left edge of the board to the first finger outline on the far left. Then measure this same distance from the far right edge. You will see the right one is slightly smaller.
This difference causes the alignment problem at the egde of the boards.
So far my solutions is to center the pins board on the pins side the same way I did the tails board on its side. Then I drilled a hole in the jig's side farther to the right and installed the right alinement bracket there for convienience. Then I establish the true center alignment for my pins board and I can cut nice dovetails repeatedly with no problems.
I have searched a lot of forums, etc. and have seen many questions about an alignment problem like this and I am begining to think there is a problem with this jig. I saw a video on Youtube "reviewing" this jig and the novice poster had a visibly obvious alignment problem at the board edges - of course he did't mention it in his video! Sorry to be so long-winded but if anyone is still awake a little help would really be appreciated.