|
A superb pdf file on Spiral Turning. An advanced
technique for the Wood Turner.
http://home.att.net/~waterfront-woods/Articles/spiralintro.html A Little bit of history The Wood Turners Love Goblet In the past it has been known for the young apprentice wood turner, when trying to woo his latest love, to turn a love goblet as a gift of his undying love for her - or so it would seem at first. The Love Goblet is a wooden turned goblet, which on the stem has one, two or three captive rings signifying the engagement, wedding and eternity rings. It was believed that the love would last as long as the goblet remained intact, with no splits in the rings or body of the goblet. The apprentice would make the goblet in such a manner as would indicate his overall intentions for the future of his current relationship. If he felt the relationship only had short-term prospects, he might have shown this in the number of rings around the stem. Alternatively he might have chosen wood which was of low quality and more than likely green (still wet), with wild grain. This would result in the goblet being unstable, having a tendency to split while drying out at his unsuspecting loves home. If he felt the relationship had good prospects and he had intentions for its future, he would very carefully choose a well-seasoned (dried) piece of the best wood in the workshop with straight grain. He would then spend many hours carefully turning the blank of wood into a prized possession for his love. She would be able to cherish it for the rest of her life because, as long as the goblet remains in good condition it is believed, does the relationship. Courtesy of Scottish Wood Craft Turning a "Carved" Vase Start with four billets of ash (or a wood of your choice) of square cross-section. Try to make the proportions so that the finished project will conform to the golden section. (The ratio of the Width divided by the Length equals approximately 0.6.) Lay up the four billets so the portion of each that will form the interior of the vase is now on the outside corners of the composite block. Stick these together with double sided tape and wrap several turns of fiberglass reinforced packing tape around the outside where I will not be cutting. If I eventually need to cut in those areas where I have taped, I put more tape in an area where I have already turned. I put this taped-up block between the centers of my lathe and turn at a relatively slow speed. Before turning on your lathe, check for clearance of the tool rest. I have turned vases of this sort where I needed to use a hand saw to cut a V-shaped notch in the block to clear the banjo of the tool rest. Cut the contour of the inside curve of your vase. (Take care that you stay clear of those rotating corners. They can hurt!) You can check your progress by multiplying your depth of cut into the block by two and that will be the width of the space inside your vase when it is finished. You do not want to turn down so far as to round off the flat surfaces of your block. I have found that if I do this I have cut too deep to allow me to achieve the contour I want on the exterior. You can turn the block so that you have a smooth cut to form the interior, or you can leave it rough. I have turned vases where I cut the interior so that it looked like it was hand carved. This creates a real puzzle when one realizes that there is no opening large enough to admit a carving chisel or gouge! This is the time to do any sanding or finishing you want on the cut portion of the block. If you apply finish, be careful not to put it on the flat portions of your billets. These surfaces form the glue joints when you glue up your vase. When you are satisfied with the internal contour, remove the block from the lathe. I number the billets at this point so I can preserve the sequence of their arrangement. Pull your composite block apart, turn the billets so the "outside" corners now form the outside, and glue them up. You should have a block that looks solid, revealing nothing of your previous cutting. When you start turning the outside, you will soon open up "windows" to the inside of your vase as your cuts now intersect with the previously turned interior contours. These windows can be dangerous so keep your fingers well away during all operations. As these windows open, you get a view of the interior shape and can easily follow with the outside contour. Leave the vase oversized at this point so that later you can make the various curves flow together. I cut a flat in the place of the cove above the bun foot that is wide enough for my steady rest. I leave a shoulder on the topside of the cut for the steady rest to ride against. Orientate the block so the top of the vase is against the drive center in the headstock and the base is supported by the live center. I now attach my steady rest so that it is supporting the vase just above where the bun foot will be and so that it is pushing the vase snugly against the drive center. Pull the tailstock away, turn the lathe on (slow speed), and shape the bun foot. I use a similar technique to shape the neck and lips of the top of the vase. Orient the vase with the bun foot against the drive center. I cut a flat in the area that will form the neck of the vase and leave a shoulder that will allow the steady rest to hold the foot firmly against the drive center. With the top held in place with the live center in the tail stock, position the steady rest in this flat. Using a drill chuck in my tailstock, I drill an appropriate sized hole through the neck to the interior of the vase. Then I shape the lips and bring the interior curve of the lips to flow into the hole I drilled. Put a cone center into the tailstock, push it up to the top of the vase, and remove the steady rest. Now I make my final cuts so that all the curves flow together and cut the cove above the foot. I elected to score and burn a couple of lines on either side of the cove. I have had people comment that they really liked the effect of the "walnut inlays" above and below the cove! If the edges formed by the interior contours meeting the exterior have chipped while cutting the exterior, you will need to dress them with sand paper or a small file. I finished my vase with a buffed wax finish that gives it a nice, soft luster. Courtesy of Woodturns Resource Copyright Nott-Us W |