Scraper'spotential for Spindle Turning

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Contemplating a Scraper’s Potential for Spindle Turning

Matthew C. Lewis

reat spindle turning is possible tool maintenance, cost, and production using a scraper if you under- speed. In short, contemplating a scraper G stand the tool’s capabilities and for spindle turning should not be driven how to apply them. You are likely famil- by community acceptance or by popular Examples of iar with the adage that real turners do opinion, but rather based on consider- not use scrapers when spindle turning. ation of the job, efficiency, and the stan- scrapers/tools for This common notion is often stated as dard of finish for the final project. spindle turning an opinion, without much explanation A variety of scraper shapes can be made beyond that scrapers are not cutting tools or purchased to provide flexibility in • Skew chisel on its side for delicate removal of small amounts of wood and therefore do not leave as clean a sur- spindle turning. These include two well- • Square-nose scraper for tenons and face as a gouge or skew chisel. Deltacraft’s known tools used in an alternative scrap- square rebates handbook, Getting the Most Out of Your ing fashion: the parting tool for turning • Parting tool for parting off, beads, Lathe (1954), however, offers this adage beads and the skew chisel used on its side and other convex shapes up for contemplation with the statement, for forming beads and pommels. • Drop-nose scraper (a variant of the “The turning of spindles can be done To avoid discussing the nuances of round-nose) for planing, coves, and beads with either a scraping or cutting tech- all possibilities for scraping tools, I will • Standard round-nose scraper for planing, nique, the cutting technique by virtue of focus on the potential of the round- coves, beads, and roughing out faster wood removal and a cleaner surface nose scraper for spindle turning. • Diamond point scraper for making being almost a must for good work.” V-grooves and beads This article offers some practical Context • Bedan tool for tenons, beads, other considerations for discerning turners, I begin with a quick review of basic convex shapes and smoothing surface addressing the term almost in this cutting tool and scraper function. passage and breaking the chains of Cutting tools generally remove wood popular turning theory by recogniz- by paring wood fibers. Paring is ing the potential of a scraper for spindle achieved when the tool’s cutting edge work. Although it may be true that the forms an oblique angle with the spin- finish from the tool is not as good, a prac- ning wood (Photo 1). A cutting tool is tical second best can be achieved with able to cut cleanly because two sur- modified technique and by factoring faces of the tool are sharpened to a fine Examples of scrapers and other tools used in an alternative scraping fashion for in the considerations of learning curve, edge which, when employed correctly, spindle turning. safety, required surface finish, ease of slices each fiber completely.

1 The oblique angle used to apply a cutting tool produces a cleanly pared surface. Figure 1. Clearance angle for scrapers is measured by holding the tool’s cutting edge next to the spindle turning.

The scraper on the other hand, when For spindle turning, in order for a held in its standard orientation (flat on scraper to be more effective using the the toolrest with the handle in a neutral bevel-rubbing technique, the angle to slightly pitched position), scrapes between the two surfaces forming the 2 the wood fibers. Scraping is done on scraper tip should generally be more acute Scraping with the tool held in its the wood’s surface by means of a burr than often recommended for faceplate standard orientation leaves a rough on the top of the scraper’s cutting edge. turning. Myron W. Curtis learned from surface on spindles. This action typically leaves a rough decades of experimentation and success- surface and occasionally torn fibers ful production turning that a shallow (Photo 2). (For an excellent discussion semicircular scraper with a bevel angle enhanced by adjusting the presentation of scrapers and burrs for bowl turning, of 57° is a good configuration for general of the chisel to the wood and by modi- see AW, vol 18, no 1, “Real Woodturners spindle turning. Still, an even more acute fying the profile of the cutting edge. DO Use Scrapers,” by Russ Fairfield.) angle (around 45°) increases the effective- The semicircular nose of the tool ness of the round-nose scraper for the makes it useful in developing curved Configuration tight areas associated with some beads, surfaces (Photo 5), concave and convex, Modern turning literature often rec- coves, and smooth curves. The cutting in addition to achieving straight lines ommends small clearance angles (or action of a round-nose scraper with this and tapers. The cutting area for the large bevel angles) for scrapers; these type of bevel is further enhanced by shear round-nose scraper is generally from angles are measured as shown in Figure cutting (Photo 4). ten o’clock to two o’clock with the 1. Using large bevel angles seems twelve o’clock position being the tran- appropriate for faceplate work (bowl Technique sition point (Photo 6), depending on turning) because the cutting action The performance and versatility of the direction of cut, orientation to the is dependent on the use of the burr scrapers for spindle turning can be wood, and the profile of the tool. on the top edge of the scraper; this requires minimal clearance between the bevel and the piece being scraped in order to apply the burr. Although the faceplate-work technique is useful on occasion during spindle turning, a more advantageous orientation that reduces tearout is to rub the bevel while applying the sharpened edge of the scraper nose to the spinning wood 3 4 (Photo 3). (Safety note: Bevel rubbing Modifying the presentation angle of The cutting action of a round-nose the round-nose scraper by rubbing the scraper is enhanced when using the tool is not recommended when scraping bevel when spindle turning produces a as a shear cutter. endgrain and/or during faceplate cleaner surface than that produced in a turning bowls, as a dangerous dig-in standard orientation. can occur.) woodturner.org 23 Copyright 2011, 2016, American Association of Woodturners. All rights reserved. as for using a gouge or skew chisel. Care should be taken not to cut on the upward side of the cutting edge (above the transition point) when perform- ing this operation, as a catch is likely to occur and the tool will slam down on the toolrest, potentially causing 5 6 damage. An even longer bevel improves A more acute bevel angle than generally The safe and effective cutting area for a the effectiveness of the round-nose recommended improves the scraper’s round-nose scraper is indicated by the scraper for cutting certain concave or ability to shear cut along curved surfaces labeled boundaries. convex surfaces in this manner. and into tight areas. The traditional tipping of the scraper, nose down, can also be used to great advantage while spindle turning where a curve with a precise radius, close to that of the scraper, is required. This technique requires finesse and a light cut (Photos 9a, 9b). A heavy cut will certainly result in 7 8 torn fibers that are further magnified by When spindle turning, gently raising the Tilting the round-nose scraper to an side grain wood that is naturally prone to tool’s handle while rubbing the bevel oblique angle when spindle turning of the round-nose scraper produces an replicates the cleanly pared surface tearout; clean-up is easily accomplished effective peeling cut. produced by a cutting tool. in this case using the shearing technique.

Considerations To improve the cut when using the typically a reason some say that a scraper Although the round-nose and other round-nose scraper during spindle is not an appropriate tool for spindle scrapers are extremely effective, it would turning, begin by rubbing the tool bevel work. The finish can be improved fairly be disingenuous to say that they produce on the spinning wood, then gently raise simply, however, by changing the orien- as consistently a clean surface off the the handle just enough to cut/peel the tation of the scraper during cutting. blade as do cutting tools for spindle wood. Using an acute bevel angle, this When making cuts that are straight, turning. There are, however, several orientation more closely approximates tapered, or gently curved, canting the noteworthy considerations in favor of the action of a cutting tool (Photo 7). scraper toward an approximately 45° the scraper that may more than make This approach will effectively cut/peel angle while rubbing the bevel will shear up for the slight degradation in surface side grain, although the finish will vary the wood fibers (Photo 8). This effect finish: learning curve, safety, required depending on the wood type and the is also accomplished when rolling the surface finish, ease of tool maintenance, direction of the wood fibers. The rougher round-nose scraper during bead, cove, cost, and production speed. finish that is frequently produced is and tighter curve cutting, the same The spindle gouge and skew chisel have a rather steep learning curve that The straight portions of the round-nose includes the potential for catches, which scraper (see right) make the nose more of a can result in damage to the piece and/ shallow dome shape and emulate the paring or turner, frustration, and elevated risk edge of a skew chisel and/or gouge when to safety. A round-nose scraper greatly shear cutting. These straight portions are reduces catch potential and also reduces ground at an angle which ensures clearance the training necessary to produce of the corners of the cutting edge when the acceptable products. Round-nose scrap- tool is rolled. This modification provides a ers are forgiving. This is not to say that clean and burnished cut as the bevel rides the turners should avoid investing the time wood. The corners created by this grind are useful for cleaning up some surface inter- to learn cutting tools, but at least con- sections, shoulders, and when initiating a sider these factors with regard to the job concave curve cut. Round-nose scraper profile. at hand and your skill level. All turners will do well to combine the use of the

9a 9b 10 Standard scraper orientation is useful on A much cleaner surface than expected can Architectural turnings such as these occasion for spindle turning when finesse result using standard scraping methods. balusters are perfect candidates for scrapers, and a light touch are applied. given the less refined finishing requirements and need for production speed. two types of tools for maximum capabil- removed with precise control (pattern- Conclusions ity/versatility when spindle turning. makers rely on scraping tools). Many A scraper’s potential for spindle turning Although the surface left by a cutting undulating surfaces are easily smoothed is a worthy consideration for the tool employed by a skilled turner is using scrapers, without the use of abra- open-minded turner who considers typically clean and free of blemishes, on sives. Scrapers, however, typically require all aspects of the task and is willing to many woods a nearly identical surface more radial pressure than do cutting stray from the mainstream in defin- can be produced using the aforemen- tools, which can sometimes result in ing the appropriate tool for a given job. tioned modification in cutting style. The undulating surfaces. Consequently, there Although scrapers are not replacements small differential that may result in the is a small investment in learning the nec- for cutting tools, they offer a versa- quality of surface texture will easily be essary feed rates, lathe speed, and pres- tile, safe, and cost-effective option for cleaned up when abrasives are applied. sure required to achieve precise cuts. some types of spindle turning. Given Furthermore, many turning projects Scrapers are easily maintained because the proper circumstances, the use of do not require a gallery-quality finish. they are made from flat stock, do not scrapers can ultimately result in a gain This is the case in the architectural world have a flute, and are easy and quick to of speed and efficiency during produc- where sanding to a 180- or 220-grit finish grind by hand. Adjustable toolrests on tion work. So, next time you are doing is acceptable for paint and staining, espe- bench grinders suffice for grinding the spindle work, consider the potential cially for balusters (Photo 10), columns, desired bevel. Scrapers are easily shop- of a scraper. You will likely find a new newel posts, architectural finials, dam- made and are in most cases less expensive friend at the lathe. age-control plugs (a cork-like fixture used than a gouge. Also, they do not require to plug pipes during maintenance), and the purchase of fancy jigs and/or many certain furniture components. long hours practicing freehand grinding. Matt Lewis’s primary interest is in tool making and turning architectural elements Scrapers provide the turner a much For some projects, scrapers are and other functional items. He consults higher degree of accuracy in producing just what are needed and will likely regularly with his friend, Myron W. specific finished dimensions because improve production speed when these Curtis, an accomplished and well-known small amounts of material can be considerations are implemented. professional architectural/production turner.

Drop-nose scraper The drop-nose scraper is a modified round-nose and was born out of necessity from more than 30 years of experimentation and use by Myron W. Curtis (an American progenitor of modern day architectural turning). A user of the round-nose scraper exclusively, Myron developed the drop-nose specifically to simplify his efforts when turning beads and coves on spindle work. Although the basic design may be modified according to task, the dropped nose feature exists to improve balance at the tool tip when tilting the blade while maintaining the rigidity of the complete cross section. By reducing the mass of the blade at the nose, the amount of work required to roll the tool is reduced and the probability of the tool rolling too far is limited, result- A drop-nose scraper for spindle turning, designed ing in better control and increased cutting precision. and made by Myron W. Curtis.