All the subsequent operations require that the parts remain in what will be their final positions relative to each other. I started this process by aligning the bed block by touch with one cheek piece so that it was flush with the bottom and back corner. I clamped these to the bench, and then moved on to the ramp block. I wanted it positioned so that the plane iron would not quite clear it when in position as shown above. This would allow me to sneak up on the ideal mouth opening during final tuning. Once I was satisfied, I clamped it in position while I penciled the edge of the ramp’s location onto the inside of the cheek.
The next step was to clamp all four pieces together with the bed and ramp in proper alignment with each other. Take the time at this point to recheck the relation between the iron and mouth opening, just to be safe. Once I was satisfied with my alignment, I bored holes for dowels in both sides of the cheeks and blocks as shown. Finck only uses one dowel per block on each side, but I liked the idea of using two to lock everything immovably together for the following steps. Short lengths of dowel are tapped into the holes and trimmed flush. They don’t have to go far into the blocks – 3/8 – 1/2″ is more than sufficient. They aren’t glued in – they just provide alignment during subsequent disassembly and reassembly, and will be trimmed away completely when the body is given its final shape.
The next step is location of the crosspin that the wedge “wedges” against. Finck recommends that the holes in the cheeks be located 1 1/4″ up from the sole, and 7/16″ above the chipbreaker. This last measurement is made at a right angle to the bed. I did this by setting the blade of a small combination square flush with the end, and then directly measuring up from the top of the chipbreaker.
I opted for a traditional crosspin for my first plane. This is a piece of wood that is 1/2″ square, D-shaped in cross-section, and has a 5/16″ round tenon on each end. This allows the pin to pivot so that the flat surface bears against the wedge for proper friction. The fit in the holes should be loose enough for the pin to pivot, but not rattle.
I have noticed that Ron Hock and others have used simple dowels in place of this arrangement. I don’t know if this approach is as effective as the traditional pin or not. It seems instinctively that the smaller bearing surface of a circle would make it easier for the wedge to slip, but I haven’t tried it to say for sure. If someone has knowledge of the relative merits of these approaches, I would appreciate a comment on the subject. A dowel would certainly make this step easier.
After cutting the piece square, I made a saw kerf 1/2″ long on each end, allowing 2″ length for the actual pin section in the middle. I then used a knife and file to bring the tenon to round, being careful to keep it centered and straight. To create the “D” shape. I clamped a block plane inverted in the vise, and passed the pin over it as shown above. The rounding makes it easier to clear shavings from the throat of the plane in use, as space is at a premium in front of the pin.
Once this is done, glue is applied and all the parts are reassembled. You can see how the dowels ensure that everything stays in alignment during the glue-up. Also note the layout marks on the cheek piece that show the relative placement of the bed and ramp blocks. Be sure that you don’t put glue on the crosspin. This mistake will render all your work so far worthless, and you will find yourself repeating the entire process. At this point, it’s simply a matter of applying clamps and waiting for the glue to dry.
Next time, we’ll finish things up and make some shavings. Stay tuned!