Making the Precision Router Base
7/30/08: I have made five more of these jigs and have them available for sale should you not want to make one. Have one shipped to your door for $115.00 + $10.00 shipping. Just send Paypal to sylvan@sylvanwells.com (paypal address). As soon as I receive notification from Paypal I will ship the unit as I presently have them in stock! Enjoy! 9/24/07 - Only two left of this run!!!!
This router base is based on a design by Tony Karol which he so graciously posted on one of the forums sometime in the past. However, his photos did not delineate a step by step procedure for making the base. If you were not familiar with jig making, the base could have been a formidable project. No parts were sized or specified for the beginning guitar maker. I thought it would be useful to give a step by step description of building the router base.
The base is primarily designed for cutting rosettes. It has a fine adjust feature (in this instance, the Telecaster knob), that is, you can set the exact distance within .001” merely by turning the fine adjust knob clockwise or counterclockwise and thereby moving the locating pin a set distance. The fine adjust knob moves the locating pin .050” for each full revolution of the knob. Therefore, if you need to enlarge a rosette cavity by .012” merely turn the knob a quarter turn. For example, suppose you measured a rosette with your dial calipers and its’ width is .210”. A 3/16” bit is .185”. Make the first cut. Now you know that you need to widen the slot by .025”. Turn the fine adjust knob ½ a revolution and the rosette will fit perfectly. If you need a little more space adjust the knob accordingly.
As you can see, this is very handy for guitarmaking. Here is exactly how to make it.
Parts:
¾” UMHV Material
13” ¼” Steel Rod
4” ¼” x 20 threaded rod
2 Locking Screws ¼ x 20 x ½”
1 ¼” lock nut
2 ¼” nuts
2 1 ½” wood screws
2 ¼x20 knobs ½”- ¾” length
1 screw tighten knob (telecaster knob)
1 1” ¼ dowel
1 1” x 1 ½” UMHV for circle cutter attachment
Cut UMHV to a length of 5 ½”. Then drill 3 holes about 3” deep. Two of the holes should be ½” in from the sides and drilled with a “F” drill bit (slightly larger than ¼”). Drill one in the center with a 7/32” drill bit. This hole should be slightly elevated from the center of the piece (for adjustment knob).
Using masking tape mark the piece into three distinct pieces (1”, 1” and the rest) so you can reassemble after cutting apart. Cut this piece into two 1” pieces and the rest is the base.
Cut one ¼” threaded rod to 4”.
Cut two ¼” rod to 6 ½” pieces.
The center 1” piece should be drilled out from 7/32” to “F” bit in the center hole. The outer 1" piece should be threaded with a 1/4 x 20 tap.
Drill locking holes in all three pieces (two for the rods in the base and one each for the parts that move). Thread all locking holes with a ¼ x 20 tap.
In the second piece closest to the router base drill a ½” hole over the “F” hole so that the locking nut will be countersunk into the piece.
Assemble the 4” threaded rod with the locking nut. Insert into the second piece so that the locking nut is countersunk. Spin two nuts on the threaded rod from the other side locking them against the second piece. Attach the threaded first piece on the length of threaded rod that is now attached to the second piece.
Drill a ¼” centered. hole in the 1” x 1 ½” UMHV. Drill two 5/32” holes along the edge of the piece so it can be screwed to the second piece. Attach this piece to the second piece with two wood screws.
Attach the 6 ½” rod to the base with two locking knobs. Slide the assembly onto the rods. Attach the two locking knobs to the moving assembly.
Attach the telecaster knob to the threaded middle rod. Congratulations! You have finished the project.
To use your new precision base, merely adjust the main unit by loosening the two black knobs and sliding the unit into position. To fine adjust, tighten the black knob closest to the telecaster end of the jig and turn the telecaster knob (1 turn = .050"). I use it in conjunction with a dial caliper. By measuring the width of the rosette to be inlaid and choosing a downcut router bit just under the right size, I will make a cut. Then I will fine adjust and add the thousandths of an inch necessary to make the width of the rosette plus .005". I find this gives a great fit! Have fun!