Sunday, February 1, 2015

Ancient Knowledge Task Model #2

Finished the layover valley sleeper task model. The hip rafter fit better than I expected. The canted rafter on the left hand side of the task model was almost a perfect fit. It's fun when the geometric lines on the drawing board are drawn correctly and produce the results you're looking for. It's not so much fun when the the lines don't work on the timber. Here's some pictures of the completed task model and pictures of the tools it took me to build the task model. At this point the witches cut, Hexenschnitt, for the hip rafter is a no brainer. The witches cuts on the layover sleepers aren't that hard, as long as I'm paying attention to what line does what. The hardest part of the building the task model for me was using the draw knife and hand planes to edge bevel the layover valley sleepers and hip rafter.

I bought a new Japanese 2 13/16" smoothing plane. I still need to work on setting it up. The Japanese planes are not functionable until you set them up. Besides shaving down the side of the plane when the blade sits, you suppose to plane the bottom of the plane to make it perfectly flat. I'm hesitant on planing downing the bottom of the new plane. I could really screw that up. Oh, yeah, you're suppose to sharpen the blade 500 times at the same angle on the 5000 grit water stone. I got to about 100 strokes, before I thought it was sharp enough. I sharpened the new Barr Framing chisel on the 5000 grit water stone. It made the tip of the chisel shine like a mirror and is pretty sharp. I tried cutting the hair off my arm with the chisel and it removed the hair easily.  I also sharpened the Barr bench chisel Billy gave me and it's pretty sharp as well.





I bought a new Barr draw knife, but it's a little big for task models. I'll use it on a real hip rafter. I sharpened my old draw knife on the 5000 grit water stone as well. It's a long process to sharpen the draw knife. I use the Diamond Whetstones® fine 600 grit, coarse 325 grit, before I used the 5000 grit water stone. I still need to get a 2000 and 4000 grit water stone.


Here's a picture of the 3 saws I mainly use. The one on the right has about 28 teeth per inch. I start all the cuts with this saw. The one in the middle has about 25 teeth per inch and it has a wider blade. The one one the left has about 24 teeth per inch and dose not have a reinforced top arm for most of the blade. It's good for finishing off the cuts that the other two saws can't complete.



One of the main reasons I wanted to study this task model was to make sure I could develop the seat cut on the valley sleepers. The cuts are not perfect on the valley seats. I'm not sure if was my cutting or the geometry wasn't perfect enough.










This was great. The two valley sleepers edge bevel and the hip rafter edge bevel aligned perfectly. Each time I used the draw knife and plane to edge bevel the rafter it wore me out.











Drawing showing the geometric development for the lower claw on the canted jack rafter to layover valley sleeper.







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