Replies

1. 
   4DThinker | Mar 15, 2004 10:16pm | #1

   Is it a jig for the table saw, router table, hand held router, or what?

   We make reliable finger joints with a jig composed of a 12" piece of key stock (3/8" square or whatever size finger width you want) screwed to a piece of plywood that has some laminate glued to it's top.  We use a tall push fence that slides on the keystock to hold the stock upright.  A 3/8" carbide spiral straight bit in the router table gets set through a hole in the plywood, the plywood gets clamped to the table, the bit is set 3/8" from the keystock and at whatever height your boards are thick. 

   Picture attached.  It takes a little fussing with to get the space between the keystock and the bit just right, but I use a smaller piece of the same keystock+a piece of paper as a spacer, and the fingers slip together perfectly every time with just enough room for glue.

   4DThinker

   
1. 
   Ron6978 | Mar 16, 2004 03:17pm | #5

   THanks for reply. It is for my table saw.

   Ron from Pittsburgh

2. 
   scooter1 | Mar 16, 2004 04:14am | #2

   Ron, this is one of the hardest joints to make consistently good. Let me give you my tips. First of all, the problem is with your spacing between the key (finger) on your jig and the saw blade. This needs to be adjusted ever so much. This will take some trial and error. Once you get it right, keep the jig attached to your miter guage and don't re-set it.

   The best advice that I can give you is some I got here. Get a good dial caliber and assuming you are doing quarter inch fingers, make your fingers .249 and make the spaces .251.

   Adjust your dado set for a cut that's .001" wider than the joint fingers (.251" in my example). With stackable dado sets you can place commercially made shims between the cutters, or make your own shims from various papers (standard tablet paper measures .002-.005" thick, some tissue and waxed papers measure .001" thick). With your calipers, check the width of the fingers. They should be .001" under your desired finger width. (For my 1/4" fingers the calipers should read .249".

   There is a good article on what I am saying at.

   http://www.woodmagazine.com/default.sph/wcontent_user.class?FNC=BottomPageLink__Astory1_html___7___47___129___146___6

   Try this, it worked for me. Now go get a good set of dial calibers.

   Regards,

   Boris

   "Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934

1. 
   BG | Mar 16, 2004 02:15pm | #3

   Ron,

   Just to echo what others have said and add a coupla points from my vast array of mistakes.  I use the dial calipers all the time and use the Incra miter on both the TS with dado blades and the router table with the upspiral bit...to cut the box joints.  Also, after your measurements are set...make sure your TS insert is flat...and use a fresh piece of stock as a backer for every cut to prevent tearout...  

2. 
   Ron6978 | Mar 30, 2004 04:40pm | #6

   Got going after a bit. Have to mix in work, family, etc. with my woodworking. I do in fact have an excellent set of calipers that I got from my Dad. He was a tool and die maker and has some neat tools. Finger joint is hit and miss to a degree, but the calipers did there job. Box came out pretty good, and think my next stab will be better. Jig is touchy/feely type deal. Saw the one in Shopnotes, but wanted to keep it a bit simpler. Use tap/tap method of adjusting spacing.

   Thanks for input and reply to question

   regardsRon from Pittsburgh

1. 
   brulew | Mar 30, 2004 04:55pm | #7

   The nice part about the ShopNotes jig is that with minimal effort when building it, you can build the jig for as many different sized finger joints as you need.  I cranked out 1/4", 3/8", 1/2" and 3/4" even though I need only the 3/8" at the time. 

   The best part is that once you go through the trial and error (with or w/o calipers) and set the screw, you never have to play with it again -  and that goes for any of the jig templates.  Take one off, use another, come back to the first and the set up is there. 

   I had a 'tap-tap' jig for my router table that served me well albeit a little tearout regardless of backerboard (I did dovetails on it, too).  But when I bought a dado set and built this jig, my wife got sick of 'appreciating' the quality!

3. 
   brulew | Mar 16, 2004 03:08pm | #4

   I built the finger jointing jig from the ShopNotes article a year or 2 back.  It has a built in adjusting screw for the spacing between blade and registration finger which is what makes the joints fit just right.  A little trial and error to get the fit just right. 

   ShopNotes # 62 March 2002.  You can back order it or depending on your skills, figure it out from the picture.