Brief Description: My Formblock System - A how to (part 3)
11. You should now have two identical pieces a. NOTE: some pieces (nose rib, center rib, back rib) have different lengths depending on where they are installed. See my kitlog for more information on the 0.125” shims I installed on my formblocks. 12. Now a radius must be put on the forming block. I used a 1/8” radius router bit in my router table and did both sides of the forming block. 13. The backing block must be about 1/8” smaller than the forming block to allow room to hammer over the rib radius. Here’s my trick: repeat step 12 but then take this backing block over to the stationary belt sander carefully sand to the edge of the radius. Ensure belt sander table is perpendicular. Now your backing block is exactly 1/8” smaller.
The Lightening Hole Blocks (or Lightening Jig 3000™ aka LHJ3K) are sized from the Master Rib BACKING block. The backing block is 1/8” SMALLER than the Master Rib Block. This allows the rib (after flanging) to sit flush on the LHJ3K. Also, my LHJ3K has 3 layers. A bottom (backing) layer, a middle (forming) layer, and a top (alignment) layer. So that means that 3 shapes will be needed. 1. First clamp the master rib BACKING block to piece of MDF 2. Trace around it 3. Carefully drill (transfer) all jig pin holes and lightening hole centers a. Use same procedures as above 4. Remove Master Rib backing block 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 lightening holes in piece now designated Middle layer a. Clamp your work securely to drill press table, hand pressure is not enough b. Holes are sized per plans for this block 8. Repeat steps 1-5 two more times using piece created in step 6 in place of master rib form
