Brief Description: My Formblock System - A how to (part 2)
The shaping blocks are traced off of the master rib form + flange width. Flange width is 9/16" to 1/2" depending on rib location. 1. First clamp the master rib to piece of MDF 2. Trace the flange around it using the marking tool as seen on page 5 of "The Bearhawk Book" 3. Carefully drill (transfer) all jig pin holes and lightening hole centers a. Drill one hole b. Insert bolt (AN3 or equivalent) into hole to stop any misalignment (ask me how I know about this) c. Drill other hole i. NOTE: exact jig pin hole placement is important to my system as the router blocks and the lightening hole jigs all use these holes d. Each of my ribs has two 3/16” jig pin holes with bushings i. My Center Rib actually has three jig pin holes as I made a seperate oval “E” hole lightening hole jig e. Lightening hole centers are 1/4” holes to account for the 1/4” drill bit on the circle cutter 4. Remove Master Rib Form 5. Rough cut MDF with a jig saw staying about 1/8" from the line. 6. Using a stationary belt sander carefully sand to the line. Ensure belt sander table is perpendicular to belt surface 7. Using drill press and circle cutter, cut all lighting holes a. Clamp your work securely to drill press table, hand pressure is not enough b. Holes are sized per plans for this block (do not add flange dimensions yet) 8. Repeat steps 1-5 one more time using piece created in step 6 in place of master rib form. This creates the backing block 9. Counter sink at jig pin locations on “lower” layer of router block to allow 2” long bolt head to sit below surface of MDF while routing. 10. After bolting these two new layers together, use a flush trim router bit, shape rough layer to match finished layer.
