|Project by Lumberpunk||posted 11-29-2014 10:44 PM||2204 views||10 times favorited||3 comments|
Last year I built the Smart URB (Ultimate Router Base) http://lumberjocks.com/projects/98167
I have a large bookcase project with 104 mortises (and 104 tenons) so I decided it would be a good idea to build a jig to speed up production. Since the Smart URB already has micro adjustablilty I thought it would be a good idea to incorporate it into the design.
The jig is based around a piece of 1 3/4” Birch with router t-track on the top edge and two routed into the work face. Sliding stops on the top edge limit router travel and overhang the edge by 1 1/2” on the work side to aid in leveling the workpiece Pic 2. The stops have blocks glued to the back edge to keep them square to the face when they are screwed down. A stop can also be fixed to the face for repeat cuts.
Once the stock is leveled and clamped (home made hold downs… something with cams coming soon) the URB sits on top and two accessory fences trap the router around the jig and the workpiece.
The bit can then be aligned with the mortise walls by using the micro adjust on the URB to dial the bit into place (pic 4 shows my new quick release system for rough adjustments. There are half nuts embedded at the end of the arms of the curvy piece, a bolt tightens and releases it from the threaded rod and a spring lifts it when released.)
After that is done the stops are set for the end of the mortise by lining up the bit with the layout lines and setting the stops on top of the jig.
Here it is set up and ready to route.
The whole jig rests on a wide plywood base for clamping to my bench and providing a flat surface for the anti-tip foot on the URB (pic 5)
Kerfs in the bottom of the jig provide clearance for extra clamps if needed (bottom of pic 2)
Pic 6 shows the results :). I cut two test mortises so far, (1/4” spiral upcut) 1 by going down 3/16 at a time and routing back and forth, which gave me a pretty sloppy mortise (.263 +/- .005), and one by repeatedly plunging full depth and then clearing out the waste which was much nicer (.251 +/- .002).
I think it would be pretty easy to convert the jig to cut tenons also but I am pretty happy doing them on the TS at the moment.
Please excuse the poor light. I am working on it :)
-- If someone tells you you have enough tools and don't need any more, stop talking to them, you don't need that kind of negativity in your life.