Woodworker's Journal winter-2009, страница 69
Back Ladder (Front View) Once the mortise reference lines are drawn on the posts, you can easily transfer rung-mortise locations directly from the story sticks. Locating and Marking Mortises I use my lathe's indexing head to lay out penciled reference lines to locate the rung mortises. An indexing head is a disk centered on the lathe's axis of rotation. The disk on my lathe has 36 equally spaced holes drilled near its circumference. A spring-loaded indexing pin allows me to lock the head at any of these 36 stops. I can, therefore, lock the head and draw a line along the length of the outside diameter of the post with my marking jig (see bottom photo, facing page). That line will be exactly parallel to the lathe's axis of rotation (the post's centerline). In the case of the back posts, after drawing the first line, I release the locking pin, count 10 stops, reset the locking pin and, with my marking jig, draw a second line. These lines are then 100 degrees apart on the post's outside diameter. This 100-degree separation is the WINTER 2009 69 Seat Angle Detail (Section View) The author uses the indexing feature on his lathe to determine and mark the 80'and 100° angles. |
