Woodturning Design

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Ask Dale is a regular column featured in Woodturning Design. Listed below are the questions and Dale's answers from Issue 9.
I used to finish most of my projects on the lathe until I noticed that my scroll chuck jaws were becoming increasingly hard to move because of all the gunk between the jaws and other parts. Is there any hope for this chuck? Can I take the chuck entirely apart to clean it and, if so, how do I go about it?
Chucks are manufactured with tolerances that allow for small amounts of dust, dirt, sanding debris, or shavings to accumulate without hindering the expansion and contraction of the chuck. Usually, even during the finishing process, little material should be getting into the jaw slides or interfere with the action of the chuck. If “gunk” is seeping between the jaws and other parts, your method of finishing needs to be changed so the “gunk,” whether it is an oil finish or lacquer, is not applied in such a manner as to run down into the chuck parts. However, for this discussion, I will assume the chuck has parts that are sticky from finishes as well as having a lot of dust, grease, and dirt between the moving parts. The first thing I would do is saturate the dirty areas with WD-40, a solvent lubricant that will loosen many types of material. Leave the chuck for an hour or two (or even perhaps overnight) to allow for maximum penetration of the WD-40, then use a stiff bristle brush and an air hose to remove the loosened grime and dirt. While this is being done, expand and contract the jaws to “full open” and “full closed,” cleaning and blowing material away when the jaws are in different positions. Do this several times and the chuck will likely function without further treatment. If the chuck’s action is still unsatisfactory, follow the instructions in the chuck manual and disassemble the chuck. This is not hard to do, but be sure to study the way the chuck is put together as you are dismantling it. Be sure to keep all the parts, putting them in one place like a metal can. You may not need to take the chuck completely apart. If the inside looks reasonably clean, spray with WD-40 and blow it out with compressed air. The parts that still have finish on them need to be soaked in lacquer thinner. Fill the can containing the parts with enough thinner to cover and let them soak overnight. This will usually soften any finish so it can be scraped off. Final cleaning of the metal surfaces should be done with steel wool soaked in lacquer thinner. Keep in mind that lacquer thinner will dissolve the walls of a plastic container, so DO NOT USE PLASTIC. Also, lacquer thinner is highly flammable, so don’t use it around open flame or near furnaces. Use it only in a well-ventilated area, preferably outside. If the metal surfaces are not cleaning up the way you would like, repeat the soaking and cleaning cycle. Be sure to use gloves when using lacquer thinner. If the chuck is really dirty, the whole chuck may need to be soaked and cleaned. Once the parts are clean, give all the surfaces a light coat of WD-40 and re-assemble the chuck. Be sure the jaw slides and scroll are in the correct positions as you assemble the parts. The chuck should work like new.
I have a “reversing” feature on my lathe, which allows me to change its direction of spin. Short of sanding, is this a practical feature? How safe is it to turn “backwards”?
Reversing a faceplate turning is usually done during the sanding process. This technique was introduced to the American woodturning scene about 30 years ago. While sanding, the rotation causes some of the flat grain fibers to lay down rather than being cut off by the abrasive paper. Spinning the bowl in reverse will cause these fibers to be cut off and produce a smoother surface for finishing. However, be sure that the chuck or faceplate does not unscrew from the spindle. Be sure the chuck is on really tight or, better yet, add a set screw to the chuck or faceplate to lock them onto the lathe spindle. At the 2005 AAW symposium, I watched a turner using the reverse technique for hollowing out hollow forms. Because this is a scraping technique, there is no problem with getting in position to rub the bevel and shear cut as when using a gouge. For reverse turning, the cutter is mounted similarly in the positions used for regular turning, only the cutting area is on the back inside of the hollow form. This allows the tool handle to be positioned toward the front of the lathe, making for less leaning and reaching and providing a more comfortable position as well as a better view of the cutting tool. Some people with shoulder problems have adopted the reverse procedure because it better meets their needs. Keep in mind that this method requires scraping tools and technique as well as the set screws installed in the chuck or faceplate to prevent the set up from spinning off the spindle. Safety is a primary concern when reverse turning or sanding!
I need to turn a number of spindles for a staircase I am planning to build. However, I am not that good of a spindle turner and hesitate to get started on this project. I have read recently about lathe duplicators on some turning forums and am intrigued about using one. Are they efficient and easy to set up? Will I get a good finish off the lathe?
There are a number of duplicators on the market, but I am not aware of any that will come near the quality of work produced by a good spindle turner. Some of the very expensive automatic duplication lathes produce acceptable work, but the machines cost upwards of $10,000. The more they cost, the better they work! Duplicators, which can be set up on a shop lathe, typically use a small cutter in a scraping mode. Wood removal is slow, and the tracing unit is working from a pattern which must be adjusted at the cutter or pattern after each pass, allowing a cut of about 1/8" at each pass. The cutter is usually a blunt V-shape so it can reach between areas that require sharp lines. Scraper cutters sharpened to a sharp “V” will not stay sharp very long and they dull quickly, so cutters are sharpened to a blunt V-shape which will hold an edge longer. The surface quality of a turning produced by a scraping-type duplicator typically shows a rough surface with torn grain or pulled fibers. Sanding will not usually remedy this problem because a lot of sanding on a spindle will erase the sharp crisp lines and clean surface normally found on a first-class turned spindle. Some turners use a duplicator to rough out the shape while leaving the spindle at 1/16" or so oversize. After roughing out, the spindle is cleaned up and brought to final shape with a sharp skew, gouge, and parting tool with very little sanding.
Should I bolt my lathe to the floor? I have asked a number of folks this question and am getting conflicting answers.
I see no reason why a lathe should not be bolted to the floor, once you have decided where you want the lathe to be. In fact, some light-duty lathes may require bolting to the floor or bench just to keep them in place during use. However, some precautions need to be taken: 1. The lathe footprint must be level and secure. If the floor is not level, the lathe needs to be leveled with shims. Bolting the lathe to an uneven floor may twist or torque the bed and cause the headstock and tailstock to be out of alignment causing the centers to be unable to line up. For some work, such as drilling holes on the lathe, it is critical that the centers are in alignment. 2. Bolting the lathe to the floor allows the lathe to remain in place during normal use. However, bolting down does not mean the lathe can be abused by turning beyond the regular capacity of the lathe. Large, out-of-balance lumps of wood can damage the lathe due to centrifugal force, which is directly related to the weight of the block as well as the RPM of the lathe. If an off-balance piece flies off the lathe, the operator can be seriously hurt and, in extreme cases, killed. Wood is a natural material and seldom of uniform density. Variations such as knots or moisture content will cause the work to be dynamically unbalanced causing vibration when the piece is rotated. The higher the speed, the greater the vibration and the greater the chance of the work flying off the lathe. Even though bolted down, lighter lathes need to be run at slower speeds than heavier, massive lathes.

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