MCW Apr '10 Demo
May 2, 2010Public
Photo: Patrick O'Brien enjoys making signature natural-edge forms out of "branch wood" -- cutoffs from plain old "waste" tree branches. In this demonstration, he is going to show us how to make one of these little winged vessels, and he will begin a tall, thin goblet.
Photo: Patrick makes a point to the crowd about the raw material, a common piece of a maple branch.
Photo: There are subtlties of design. The orientation is very important to preserve just the right amount of bark evenly all the way around the top and, quite possibly, a bit on a side. Patrick mounts the blank on a screw chuck and brings up the tailstock for added support and safety. This could also be done between centers, driving it with a spur center.
Photo: After a little roughing from the tailstock end...
Photo: Inspecting progress of the refined shape -- that cut under the rim can be a little tricky.
Photo: With the form taking shape on the lathe, Patrick reminds us of the goals.
Photo: The piece has been roughed on the outside and reversed on a tenon into a scroll chuck -- and, man, what a chuck! Patrick likes this large Talon 120 because it's shape makes it very safe to use even when working on the chuck side of a piece.
Photo: Preparing to hollow... The angle of attack of the gouge is important, because one skate spiral backwards will ruin the entire piece.
Photo: Initial "back hollowing" is done with a bowl gouge or spindle gouge -- use your favorite. Work from the center to the outside with the flute aimed to the left and up a tad, and cutting with the lower tip.
Photo: Patrick sands each section as it is completed. This is a good time to do a little around the rim.
Photo: .More hollowing with the gouge. At this point, he is leaving the walls quite thick.
Photo: Time to start measuring the depth -- we wouldn't want to make a funnel.
Photo: Measuring the thickness of the body of the vessel. Time to switch to a hollowing tool.
Photo: Final hollowing is done with a standard hollowing tool with an extra arm that is supported on the tool rest. In this way, the tool is well supported, and the cutting angle is safely controlled. These are alternately called an "outrigger" or a "torque arrestor", depending on which part of the world you are in. This tool takes a lot of the physical and mental stress out of hollowing and is highly recommended.
Photo: Patrick uses a hook-nose scraper to get that difficult area up right under the rim. One with a negative rake can be a little safer than a traditional, flat-topped one. You can easily make this modification on your grinder.
Photo: The hollowing is complete -- time to reverse and remove the chuck tenon.
Photo: Note the Kirsten Cone in the headstock. You can do the research -- and you can make your own out of a variety of materials and designs. The object is to get the pressure between the headstock and the bottom of the vessel, not the rim. The cone is loose on the rod and only brought up gently and locked in place after the piece is firmly between centers. If you wish to retighten the tailstock, the cone must be loosened first.
Photo: Turning off the tenon...
Photo: Patrick rolls up sandpaper to get that narrow area under the wing.
Photo: That's it...
Photo: Ready to cut off he nub, and the piece is done.
Photo: In the remaining time, Patrick will begin a very tall, thin, natural-edge goblet like this one.
Photo: Chucking up another branch.
Photo: A little roughing round, followed by the beginning of the definition of the inside of the rim.