Tablesaw Miter Jig
Are you ready for on-the-money miters? Here's the solution.
To build this jig, first place one miter-slot guide into each slot on your saw table. Align the 1/2" plywood base on top of the guide, long edges perpendicular to the miter slots. With the plywood resting on the tablesaw surface, drill 5/32" shank holes through the plywood and into the guides just far enough to mark their positions. Remove the plywood and guides and drill 7/64" pilot holes through the guides. Reposition these pieces on the tablesaw, and attach the guides with countersunk #8x1" brass wood screws. Drive the screws about halfway through the guides, and lift the assembly off the table. Drive the screws completely, and sand off their protruding tips. Again, place the jig onto the tablesaw surface, turn on the saw, and cut a kerf about halfway across the width of the plywood.
The key to this jig's accuracy is installing the miter fences precisely at 90°. The drawings below take you through the first two alignment steps. Use this process to temporarily attach each fence with two #8x1" screws. Test the fences for accuracy by cutting four sample pieces, each about 1" wide and 4" long. Hold them together with a rubberband and check for any gaps at the miters. Adjust the position of the fences as necessary by tapping them with a hammer. Once you're satisfied that the fences are in exactly the right positions, attach each of them with two #8x1" screws. Finally, to help hold your workpieces steady against the fences during cuts, attach adhesive-backed 100-grit sandpaper to the fence faces where shown in the photo above.
If you like this project, please check out the hundreds of shop-proven paper and downloadable woodworking project plans in the WOOD Store.
Comments ( 5 )
Add your comment
How about using a drafting T-square for an accurate 90-degree measurement?
3/19/2010 08:36:37 AM Report AbuseThe big problem is that I have never found a square framing "square". The trick of using a punch in the corner will not correct (or even move) a steel square.
3/14/2010 03:27:33 PM Report AbuseI have some picture frames to build for the new grandbaby, and this will without doubt make the miters truer and easier to mill, thanks for making it available
3/11/2010 01:42:39 PM Report Abusefor safety add some filler stock to the backside of the fences. keeps thumbs away from the blade and reenforces the fences. I user some scrap 2x4 to make mine.
1/28/2010 04:56:55 PM Report AbuseI built one for each of my saws. Works great.
12/10/2009 05:05:46 PM Report Abuse