Here is another “dial indicator on a stick” idea. This one is for making measurements when using a tenoning jig.
BTW, click on the images to see the uncropped originals.
The commercial tenoning jig that I recently bought from Rockler looks like this:
Notice that the sliding base remains above the sub base that is fixed to the miter slot runner. The cut line of the saw blade can be referenced to the edge of this fixed sub base and will not move nor be obstructed regardless of the position of the sliding base.
Here is my typical setup for a tenon. I like to make my shoulder cuts first, but don’t want to play golf, so I use a spacer block to keep the end of my tenon off the table top. This tenoning jig on my saw requires this anyway if the sliding base is more than 3/4” away from the saw blade.
Here is my tenon jig measuring stick.
The end “step” in the stick is thin enough to slide between the table top and the sliding base of the tenoning jig. It is a bit wider than the distance between the edge of the fixed base of the tenoning jig and the cut line of the table saw. The middle “step” in the stick thins the 3/4” scrap I used for the stick so that it is thinner than my spacer block and will clear under the end of the work piece. The fence along the right side of the stick positions the stick consistently relative to the operator side of the fixed base.
A side view of the stick.
I used a #12 flat head wood screw to attach the dial indicator to the stick. A 1/4” wood screw (#14 I believe) might have been better, but I didn’t have one.
Here is the tenon jig measuring stick in use
The dial indicator is zeroed by making a cut with the tenoning jig, positioning the measuring stick like this for a measurement, and then adjusting the dial on the indicator to read “zero”. From that point on you can use the measuring stick to precisely position the cheek of the tenon relative to the face of the workpiece. Since my dial indicator is calibrated for decimal inches, I use a digital caliper with decimal readout for my measurements of the mating workpiece and do the subtraction.
I still get a bit confused reading the “rotation counter” on the dial indicator, so I’m thinking of actually calibrating the generally useless ruler/pointer on the tenoning jig so that it tells me the nearest 0.1”.
It might also be helpful to add a sufficient number of rare earth magnets to the end of the measuring stick to hold it in position during a measurement.
Today I used this measuring stick to cut and fit 16 tenons in mostly fir stock that was thicknessed last week but this week is a variety of thicknesses. Nevertheless, this measuring stick made quick work of fine tuning the tenoning jig for each tenon. I typically spent more time rounding the ends of the tenons to fit into the plunge-routed mortises than I spent getting a snug fit on the tenon thicknesses.
-- Greg D.