Technique for Ripping Plywood

Procedure

When mass producing 16" wide strips of plywood - or a sheet of OSB divided into 3 strips - the technique is to cut right from the full pallet of OSB. A full pallet (brick)weighs about 1.5 tons, and it is shaped like a cube. In this form, all the edges line up. To divide into 3 strips:

1. Use a 6" screw and connect the top 12 layers together for cutting. Use 2 screws, one at about 16.5" on the 4' side, and another one opposite. This will prevent the OSB from twisting on you, since the 12 layers weigh over 500 lb and will not shift when acting as a monolithic block because they are screwed together.
2. Take a circular saw - corded preferably due to batteries running out - and with a 16" edge guide, cut one side. Then cut the other side. A typical 7-1/4" saw may cut 4 layers at one time.
3. Once cut, remove the 2 outer strips - 8 strips total. Note the middle strip is screwed down. To free the screw - just drill further through 2 inches - thus use a drill bit of 2" length. This liberates the layers of OSB through which the screw punched through. You will be left with a small hole through the cut OSB - which is ok.
4. Once all 4 top layers are removed - repeat the process starting from step #2. Keep drilling the screw through after cutting to liberate the OSB as above. Continue this until you go through the whole pile.
5. Stack the strips on pallet halves (semipallets) right next to the pile. After stacking about 40 strips - move the pallet away into position for truss assembly (assuming these strips are for trusses) - under the working table so that a person does not have to walk away to pick up OSB material. Put a semipallet under the mid section between the saw horses for 24' truss fabrication - and move one more to each side - so there are 3 stacks of 50 under the work jig. Move the semipallets using pallet jacks.
6. Continue stacking piles of 40 - so that means prepare a 3 pallets ripped in half - which means 3 pallets of 40 strips, and 3 pallets of 28 strips. A full pallet = 68 sheets = 40 + 28

Time Calculations

• Total number of strips generated is 204 (68*3)
• A 7" circular saw goes through 2" thick wood at about 100 IPM (inches per minute). This means we are cutting 12 strips (2 cuts) every 2 minutes. This assumes no measurement time - hence a saw with an edge cutting guide is key. Such as Rip-Cut
• A pile of 68 sheets of OSB requires 17 steps in depth (204 strips/12 strips=17)
• Just the cutting time is 34 minutes.
• If pallets are laid in place, stacking time should be 30 seconds - just taking the strips and moving them off to the pallet.
• The screw-through may be more tricky - but that should take 30 seconds to screw down both screws, so that the mid strips are liberated.
  • Thus screw-down/strip liberation and stacking should be a minute per course - adding 17 minutes for 17 courses.
• Moving the pallets into position, should be a minute each. 5 pallets - means 5 minutes.
• Thus, total time should be around 56 minutes for cutting and stacking OSB sufficient for 68 of the 24' long trusses.