|Project by rwyoung||posted 01-06-2009 02:27 AM||10922 views||25 times favorited||15 comments|
Been reading about ski jigs for routers over at www.routerforums.com and decided to make one and see if I could use it as a thicknessing jig. Worked out great.
The idea is to secure the workpiece to a known flat surface. In this case I am using a sheet of 3/4” melamine laminated particle board (not shown). The workpiece is trapped on all four sides using some 1/2” plywood with sandpaper on the edge. The ski jig is adjusted so the router base is just above the surface of the workpiece. Then the bit is dropped down to mill off maybe 1/8” or 3/32” of material. This is done by guiding the skis so the router floats above the workpiece. Go with the grain if possible. Next pass can take a little more off and so on working both sides until you have the thickness you want. Just like a “real” plainer, last pass should be slight. The key is a light touch and not letting the jig flex during the routing operation as this will change the bit height.
Ski jig can be used to mill slots, route signs, all kinds of stuff.
3/8” truss rod used to suspend plunge router base. 18” long each. Note, router is fixed to the rod, it will not be sliding along the rod.
Skis made from two layers of 3/4” plywood. Started out as about 11-1/2” by 7” and then I made them into trapezoids. The seperation of the slots is a function of the router base.
The jig can flex under the weight of the router but by adding a 3rd rod near the top of the back slot, I can stop the flex. A future modification to the jig will be to add two blocks, one to each ski, near the top on the “back” side for this re-enforcing rod. Right now I can insert one into the slots but at some heights it will hit the router base.
After several discussions with members over at www.routerforums.com I have ordered some different threaded rod that should be much stiffer than the craptacular stuff from HD.
New new ACME threaded rod arrived and it is much more stout than the cheap stuff from HD. I now have a 3’ capacity between the skis. I won’t replace the photos for the jig but I did add a photo of a special bottom cleaning bit I bought from SuperCarbide on eBay. This bad-boy is about 1-3/4” diameter and should clean things up a lot faster than a 3/4” straight bit!
-- Don't sweat the petty things and don't pet the sweaty things.