|Project by james3one||posted 05-29-2013 04:05 AM||1990 views||4 times favorited||12 comments|
This is the largest jig I’ve made so far. It’s made with two pieces of 3/4”, cabinet grade plywood. Each one measures 12”wide by 60” long, and offset by 8-1/4” – the distance from the side of the table to the blade. Currently set at a 33.125” radius, I drilled a hole through both boards with a 1/4” Forstner bit, added 1/4” bolt, two washer and two nuts(to lock in place). I drew a center line down the board from the end with several perpendicular lines for reference. Made two handles from a chunk of 2×4, set 10” on either side of the pivot point. I attached a 1”x4”x42” piece of poplar with a large hinge for the leg. Made my first 6 cuts and have 18 more to go. Have made more arched cornices than I can count, all with a jig saw. This is soooo much better. More precise and so easy.
In practice what I’ve found is that I use the handles to get the cut started, then about a third of the way through I grab the board itself and pull it slowly the rest of the way through the cut. I can support the weight of the board and make sure I have a smooth finish to the end of the cut. Its very comfortable, controlled and I never get near the blade. I took the pic from the sharp side of the saw, I stand on the other side when cutting.
As a side note: The top of the arches won’t be seen so i only have to clean up the bottom. I tried a shinto rasp, cabinet rasp, and card scraper, but best by far was a spoke shave. I have a Stanley 151 and 51, both tuned and honed. They make short work of those tool marks. Use 120 grit paper to break the edge, done.
Additions: I’ll be adding a support leg on the jig, up next to the saw. That or adding a small shelf under the table of the bandsaw to keep the jig supported from underneath. This will keep things stable while i’m getting this clamped to the saw and will prevent the jig from slipping down during use. Also take the first cut-off, secured to the table, to support the next boards as they travel through the cut.
I’ve used this jig for two different projects now. Saved so much time and added a level of precision that made installation of the second project almost effortless.
-- James, Tulsa OK,