|Project by senomozi||posted 07-16-2010 02:22 AM||7501 views||24 times favorited||8 comments|
This is a router template I recently built and used to make 12 mortises to house 6 SOSS #208 hinges. It worked so nicely and the hinges are so smooth and strong I figured I should share with fellow woodworkers who might be tempted to use these hinges. The #208 sells much cheaper than the other sizes at Lee Valley (item 00H02.16) so I made sure to build the doors thick enough to use that size.
How to build it:
1. Each half of the hinge requires two concentric mortises. A long shallow one that is 5/8” wide x 2 3/4” long x 1/4” deep. Then a shorter one that is also 5/8” wide but 1 3/8” long x 15/16” deep.
2. The jig is meant to be used with a 3/8” bit and a 5/8” outside diameter collar for a 1/8” offset. Hence the through mortise in the 1/2 baltic birch top piece is 3” long x 7/8” wide with the spacers (A and B) removed. With the spacers inserted it is 1 5/8” long.
3. I made the through mortise using a 7/8” Forstner bit. Doing the two ends first and then the center part. I squared the sides using a chisel, rasp and sandpaper with a very small block. At this stage it is critical to be precise and square otherwise the hinge won’t fit or will be too loose in the mortise.
4. Mark the center of the long side of the mortise on the wall of the mortise. This line will be used for alignment.
5. For the spacers I ripped a strip of 1/2 baltic birch ply just over 7/8” wide x about 6” long (oversized at this pont) and hand-planed the sides so it fits in the through mortise with moderate pressure. Too loose a fit and the spacers will move during the routing operation. At 6” long the blank is large enough to be held securely for the next operation, which consists of rounder off the extremities to a 7/8” diameter using the sanding machine of your choice. Finally cross-cut each end of the blank to obtain a 11/16” long spacer.
6. Next make a couple of 1 1/4” long x 1/8” wide slots with counterbores in the top part of the jig. These allows the fence to attach to the top with a couple of pan-head screws and it makes adjustments possible.
7. The fence is a piece of solid wood milled perfectly square. 7/8” thick x 3” wide x 11 1/2” long.
How to use it:
8. Remove the spacers from the jig.
9. Set the fence so it is parallel to the long side of the jig’s mortise and at a proper distance to locate the hinge mortise where it needs to be. Remember that the hing mortise is offset by 1/8” around the entire perimeter of the jig’s mortise. The fence setting is the same for the door and the frame hence it only needs to be set once. The #208 is meant to be use with 1” thick doors but one can cheat and use slightly thicker doors (I used 1 1/8”) as long as the mortises are slightly offset towards the front of the door/door frame. This allows the door to swing 180 degrees without binding on the door frame. Do a test with scrap pieces of identical thicknesses if unsure.
10. Clamp the jig fence to the door or door frame and align the centerline (step 4) with the layout line. These hinges have no adjustment so it is imperative to have matching layouts lines in the door and frame. Make sure the fence references the front of the door or the front of the door frame. This way even if it is not perfectly centered on the thickness of the door (step 9), the mortises in the door and frame will still align.
11. Make the shallow mortise first.
12. Insert the spacers
13. Make the deep mortise.
14. Unclamp the jig
15. Test the fit with a hinge.
Wood chip extraction is often an issue with this type of jig. Wood chips can get stuck between the collar and the template causing mortises to be milled improperly. I usually blow compressed air in the mortise after steps 11. and 13 then repeat the step.
Hopefully this is useful and clear.
-- Senomozi - Gatineau, Canada