Transcript
Wood Turning…. Tools & Methods Compiled from Internet Sources Owen Jones
2013
Wood Turning Tools & Methods
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Wood Turning Tools & Methods Compiled from Internet sources by Owen Jones
Table of Contents Simple Lathe .................................................................................................................................................................... 4 Types of Tools ................................................................................................................................................................. 5 Gouges ............................................................................................................................................................................................. 8 Roughing Gouges ............................................................................................................................................................................................. 9 Spindle Gouges ................................................................................................................................................................................................. 9 Bowl Gouges ................................................................................................................................................................................................... 10 Skew Chisels ............................................................................................................................................................................... 11 Scrapers ....................................................................................................................................................................................... 12 Parting Tools .............................................................................................................................................................................. 12 Turning Speeds ............................................................................................................................................................. 13 Methods of Cutting the Work Piece ........................................................................................................................ 14 Roughing Out a cylinder. ........................................................................................................................................... 15 Cutting with Roughing Gouges ............................................................................................................................................. 15 Review of Roughing ..................................................................................................................................................................................... 16 Detailed Work ............................................................................................................................................................... 16 Spindle Gouge for Cutting Coves and Beads .................................................................................................................... 16 Review of Spindle Gouge for Cutting Coves ...................................................................................................................................... 17 Review of Spindle Gouge for Cutting Beads ...................................................................................................................................... 17 Cutting with Bowl Gouges ...................................................................................................................................................... 18 Cutting with Skew Chisels ...................................................................................................................................................... 19 Smoothing a Surface with a Skew Chisel ............................................................................................................................................ 19 Review of Surface Smoothing with a Skew Chisel .......................................................................................................................... 20 Dressing Cylinder End with Skew Chisel ........................................................................................................................................... 20 Review of End Dressing with Skew Chisel ......................................................................................................................................... 20 Cutting V-‐Groves with a Skew Chisel ................................................................................................................................................... 21 Review of Cutting Vee’s with a Skew Chisel ...................................................................................................................................... 21 Cutting Beads with a Skew Chisel .......................................................................................................................................................... 22 Review of Cutting a Bead with a Skew Chisel ................................................................................................................................... 22 Sharpening the Skew Chisel ..................................................................................................................................................................... 22 Parting Tools ................................................................................................................................................................. 23 Flat Parting Tool for Grooves and Spigots ......................................................................................................................................... 23 Scrapers ........................................................................................................................................................................... 24 Finishing a Bowl or Cup .......................................................................................................................................................... 24 Finishing the Outside of a Bowl with a Square-‐End Scraper ..................................................................................................... 24 Finishing the Inside of a Cup with a Round-‐End Scraper ............................................................................................................ 25 Summary of Cutting Tools & Methods ............................................................................................................................... 26 Rules of Sharpening .................................................................................................................................................... 27 Page 3 of 27
Wood Turning Tools & Methods Simple Lathe
Simple Lathe Showing Typical Parts Common to Most Lathes This summary will discuss some of the types of cutting tools used to turn parts on a lathe. These include: ü Scrapers ü Gouges o Rough cut o Straight o Skewed o Spindle o Bowl o Round Nose o Spear Point ü Chisels o Straight o Skewed o Rounded
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Wood Turning Tools & Methods Types of Tools
Note the grinding angle relative to the vertical on each type of tool.
Spindle Tools
Faceplate Tools
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Scrapers and Parting Tool
Wood Turning Tools & Methods
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Wood Turning Tools & Methods
Go to Google.com and search for “Photos of Wood Turning Tools to see many more tools.
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Wood Turning Tools & Methods Gouges
Notice the increased sharpening angle away from the vertical on each successive type of gouge as well as the deepness of the hollow on the top of the tool…deep hollow = more blunt angle.
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Wood Turning Tools & Methods Roughing Gouges The purpose of a roughing gouge is to “rough out a preliminary work piece shape from an initial piece of wood. This can be a log or branch section, a length of 2 x 2 or 4 x 4, or a length of pieces glued together to form a blank. A set of roughing gouges of varying sizes is shown to the right. Note the physical characteristics of each of these depicted next to this photo. ü Each has very deep and wide flutes with long steep sides. ü Each is ground perpendicular to the axis of the flute. ü Each has the cutting surface ground smoothly at an angle of approximately 30º to 40º back from the nose producing a short bevel. ü Each beveled cutting surface is very smooth and regular from flute-‐to-‐flute with no extra facets. This latter characteristic is typical of every type of lathe tool no matter the style or shape: the cutting surface is always smooth and is ground on a cutting wheel with a continuous motion for each surface and no resulting extra facets. People sometimes get concerned about taking off too much metal when sharpening but it is important to get the cutting geometry correct or shaping your project will not proceed smoothly. Spindle Gouges Spindle gouges have shallow flutes above the center of the blade, 30-‐50% of the blade thickness. When looking down on the gouge from the top of the blade, the cutting end is shaped similarly to a fingernail. Sharpening of a spindle gage is undertaken by a combination of turning the blade on its axis while at the same time sweeping the handle from side-‐to-‐ side, all the time maintaining complete contact between the blade surface and the grinding wheel. In this way, a smooth cutting surface is cut from one side to the other, ear-‐to-‐ear, without additional facets. Page 9 of 27
Wood Turning Tools & Methods They are the tools of choice for finishing spindles or cylindrical work pieces where the grain generally runs with the axis of the cylinder. They are also suitable for facing cuts, shallow hollowing, drilling and beading.
1-‐in Standard Gouge
3/8-‐in Pen Making Gouge
1/4", 3/8", 1/2" and 1"Gouges
Bowl Gouges Bowl gouges have a deep flute and are used primarily for turning bowls. Also used for dishes and other hollow forms mounted on the faceplate -‐ normally with the grain running across the turning blank. Other than these characteristics, they are similar in every way to the spindle gouge.
5/8-‐in Gouge
Set of 3 Bowl Gouges: 3/8", 1/2" and 5/8"
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Wood Turning Tools & Methods
Skew Chisels The skew chisel is a very versatile tool used for cutting precise smooth finish surfaces on the outside of spindles. It is also used for cutting vee-‐grooves and forming beads. It is ideal for facing off the end of cylindrical work pieces and can even be used for shaping shallow concave curves in spindles.
1-‐in Standard
3/4-‐in Oval
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Set: 1/2-‐ & 1-‐in std & 1/2-‐in oval
Wood Turning Tools & Methods Scrapers Scrapers are produced from flat material and ground about 10º back from vertical at the cutting end. They are used to provide smooth final finishing of a work piece. The scrapers shown here are rough-‐cut blades only, obviously without handles, and also without the final sharpening to provide the Half Round Scraper Box Scraper user with the maximum material possible.
Parting Tools
Parting tools are thin tools intended to be used predominantly in the vertical orientation and used for parting, or detaching one part of a piece from another by means of a deep, narrow slot around the circumference of the work piece. They can also be used to produce the holding end on a spindle, plate or bowl that is inserted into a chuck.
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Wood Turning Tools & Methods Turning Speeds
A large diameter work piece rotating at a fixed rate of speed (rpm) will have a higher surface speed than a smaller piece. This is because the circumference increases as the diameter increases and a point on the surface of a large piece must travel farther than that on the surface of a smaller piece to make a full turn and therefore must travel faster. For instance, assume a five-‐inch diameter piece is turning at 1000 rpm. The circumference is 15.7 inches so that a point on the surface travels 15.7 inches in 1/1000 of a minute or 0.06 seconds. This is equivalent to a speed of a little over 260 inches per second or almost 22 ft/sec meaning that the cutting speed for a given tool on the surface is about 22 ft/sec. Reduce the diameter to one inch. The circumference drops to a little over three inches meaning that the spot on the surface only travels this distance in the same 60 milliseconds. The cutting speed is thus reduced to a little over 5 ft/sec. Same wood, same cutting tool, but one fifth of the cutting speed. Thus you can see why this is no longer optimum and the rotational speed must be increased to 5000 rpm to achieve the same good cutting results as was obtained with the five-‐inch piece. Before starting to cut, adjust the turning speed according to the table above. And also, as you remove wood, increase the speed incrementally to maintain approximately the same surface speed. Remember, half the diameter, double the speed and so on. Page 13 of 27
Wood Turning Tools & Methods Methods of Cutting the Work Piece
There are numerous types of procedures and cuts to be made on any cylindrical object as shown in the two figures to the left and above. Notice that the Tool Rest is as close to the work piece as practical with height adjusted for proper cutting angle and placement of the blade below, at or above the centerline of the piece. This placement will be discussed more in following sections.
To properly position: ü Set the tool on the rest with the cutting surface down and the edge just above the surface. ü Lift the handle to position the blade so the cutting surface meets the work piece but does not start cutting. ü Consider the direction of cut and tilt the blade so cutting will begin on the lower part of the cutting edge depending on the direction of cutting. You will always be cutting downhill. i.e., down into the work piece. ü Slowly lift the handle so the cutting edge slowly lies down onto the surface of the work piece and begins cutting, again on the lower part of the cutting edge. ü Maintain this cutting position, perhaps locking the handle against your abdomen, and slowly move the entire tool in the direction of the cut, taking a little bit at a time. Rotate the handle side to side to obtain the desired shape. Page 14 of 27
Wood Turning Tools & Methods ü Reposition the blade on the surface slightly before of the start of the previous cut and repeat the process in the same direction, thus deepening the cut on the work piece.
Roughing Out a cylinder. Cutting with Roughing Gouges 1. Use a relatively slow lathe speed while roughing out the piece to a cylindrical shape. A good rule of thumb is to have the speed about 50% of the cutting speed you would use for the resulting shape. 2. Set the work piece into the lathe holding it between the headstock and tailstock (Photo at right). Adjust the fit by moving the live center on the tail stock into the piece with the wheel handle. Continue turning until the piece is held firmly in place. 3. Set the rest as close to the piece as possible and slightly below center, checking by rotating the piece to insure there is no interference. 4. Turn on the lathe and set the gouge blade on the rest with the cutting surface slightly above the rotating piece. The cutting surface should be just tangent to the work piece (photo). 5. Lower the gouge so the heel (lowest part) of the cutting surface is just touching the wood. No cutting will occur but a clacking sound will be heard due to the unevenness of the piece. 6. Decide which direction you wish to move the gouge along the piece. In this case we are beginning the cut near the right end of the piece so starting near this end, slowly raise the handle until the tool just starts to cut without a lot of pressure. You may lock the handle against your abdomen at this point to maintain this handle angle. 7. Rotate the tool so the flute is facing the direction of motion by about 45 degrees. 8. Slowly move the tool blade along the piece removing material from the surface. As you gain confidence and practice, you will find you can adjust the cutting depth and speed of travel to suit our comfort level. Note that you will be cutting on the lower half of the blade cutting surface and the chips will travel down the flute towards the direction of motion. 9. Complete your cut and repeat the process while starting successive cuts a further distance from the end of the cut for each pass. You will find that the cut surface will be deeper closer to the end of travel of the cut. This cut direction is called the “downhill” direction. 10. You may frequently stop the lathe to determine your progress. 11. Continue this process until the start of the zone of Page 15 of 27
Wood Turning Tools & Methods decreasing diameter has moved to within a short distance from the uncut end. Then finish the rounding process by repeating your cutting towards that end. Continue until the entire piece is now round and the outer circumference is reasonably flat from one end to the other. You can easily determine that this has happened by laying the length of the blade on the top of the turning piece. If the surface is not round, clatter will still be heard. When it finally becomes rounded, the clattering sound disappears and a smooth contact tone will be heard instead. 12. Now increase the rotational speed of the lathe to that corresponding to the diameter of the stock in the figure on page 11. Then starting at one end, make one continuous cut with the roughing tool to finish the cylinder. You will note at the end of this process that the surface will be clean and smooth. 13. You have now completed roughing the work piece to obtain a cylindrical surface. You can check he uniformity of the piece using calipers at various locations along the piece. The golden rule of lathe turning is to always have a longer fiber supporting the one being cut. Cutting in the opposite direction will result in a very rough surface due to lack of fiber support. Again, this is called “cutting downhill.” Review of Roughing ü Rest close to piece and slightly below centerline. ü Lathe rotates at slow speed. ü Cutting surface on the work piece without cutting. You hear a clacking sound due to roughness. ü Rotate blade so flutes start to point in direction of cut. ü Lift handle until cutting starts. ü Move blade along rest while cutting towards the end of the work piece. ü Repeat process taking slightly longer cuts with each pass. ü Repeat process to cut in opposite direction with flutes pointing in the direction of cut. ü Always cut “downhill.”
Detailed Work Spindle Gouge for Cutting Coves and Beads
1. The spindle gouge has a shallower flute and the cutting edge is ground along the blade rather than straight across like the roughing gouge. Looking down from the top of the blade, the cutting edge has the shape of a fingernail. This is achieved on the cutting wheel by rotating the blade on the grinding wheel while swinging the blade in the direction of rotation. The bevel angle should be about 35 degrees. Considerable practice is required to do this properly and an easier method is to use a “fingernail-‐profiling jig” that rotates the blade while at the same time swinging the handle. 2. The spindle gouge may be used for cutting beads and coves, or fillets. Remember to always cut downhill as shown in this sketch. 3. Adjust the tool rest to be as close to the work piece as possible
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Wood Turning Tools & Methods 4. 5. 6. 7.
8.
9.
without interference and parallel to the surface. The height should be just above center. As with the roughing gouge, place the tool on the rest with the flute vertical and slowly lower it until the heel of the cutting surface touches the work surface but the blade does not cut. Slowly lift the handle of the gouge until cutting commences and then rotate the tool in the direction you wish to travel so cutting is occurring on the lower part of the blade surface. Roll the tool in a scooping manner to begin to cut the cove. Move the tool to the start of the cut and taking just a little more from the original outer surface of the cylinder, repeat this process until the cove has progressed to some depth. Remember, you can only go to the bottom of the cove because going further would mean you are cutting uphill. You thus widen and deepen the cut in stages. The other side of the cove is cut in exactly the same manner but in the opposite side of the groove. Continue cutting in reverse directions while increasing depth and width of the cove until the desired effect is achieved. Note that as the cove progresses, the tool will be rotated so it is facing more down than up at the start of each cut but then rotated as the cut progresses towards the bottom. In this manner you are always using the downhill half of the blade for undertaking the cutting process. The aim is to achieve a smooth shape with a fine finish. If you find the finish becoming ragged, you are either cutting uphill or the blade has become dull and needs sharpening. Remember that the bevel of the cutting edge always remains on the workpiece while cutting.
Review of Spindle Gouge for Cutting Coves
Start Cove on Left
ü ü ü ü ü ü ü
Cove Cutting Left-‐to-‐Right
Start Cove Cutting on Right
Cove Cutting Right-‐to-‐Left
For coves, set the rest close to the work and slightly above centerline. Run lathe at normal cutting speed for size. Set tool on rest, flutes up, with cutting surface flat on the work piece surface without cutting. Raise the handle to start cutting. Rotate the blade so flutes start to point in direction of the cut. Move blade and rotate handle to scoop out material left-‐to-‐right. Repeat process to cut from right-‐to-‐left.
Review of Spindle Gouge for Cutting Beads ü For beads, (photos next page) set the rest close to the work and slightly above centerline. ü Run lathe at normal cutting speed for size. ü Set tool on rest, flutes up, with cutting surface flat on the work piece at the top of a cove surface without cutting. Page 17 of 27
Wood Turning Tools & Methods
ü Raise the handle to start cutting. ü Rotate the blade so flutes start to point in direction of the cut. ü Move blade and rotate handle to round out material left-‐to-‐right along the surface of the cove on the right. ü Repeat process to cut from right-‐to-‐left producing a rounded top of the material between two coves.
Start Bead with Gouge on Surface
Cut Bead Left-‐to-‐Right
Cutting with Bowl Gouges
Cut Bead Right to Left
1. The bowl gouge has a deeper flute thus giving it a longer cutting edge than the spindle gouge. Again, refer to page 6. The cutting edge is ground to about 45º by setting the tool rest at this angle and simply rotating the blade without swinging the handle. 2. To use this tool to cut into the flat surface of a work piece held with the faceplate, adjust the tool rest just a hair below center and as close to the flat surface as practical. Similarly to cutting a cylinder, rotate the piece to make sure it does not touch the rest. 3. To make the cut, make sure the tool is used to cut downhill as shown in this sketch. This will insure that the resulting surface is smooth. To make the cut, place the blade on the rest with the handle pointing downward at slightly more than 45º and slowly move the tool towards the work piece until the heel of the cutting bevel just rubs the surface without cutting. Then, slightly raise the handle until cutting begins on the downhill surface of the bevel, not at the point. Then move the cutting blade along the surface in the downhill direction, swinging the handle in the direction of motion so as to maintain a uniform relation between the blade and the surface. 4. To begin the process, attach a disk of wood to a faceplate. The disk wants to have a diameter somewhat larger than that desired for the finished bowl and a thickness slightly more tan the finished height will be. We will begin by turning the outside from the bottom up in the sketch. 5. The shape shown in the sketch begins as a disk. Just as when roughing the outer surface of a cylinder, begin first near the edge of the piece and make a small bead at the edge. T this point, the shape shown above would begin by looking rectangular in cross section with a small round at the left lower side. Then, begin the second cut slightly more towards the rotating center of the piece and proceed over your first-‐cut surface, enlarging the size of the round. Continue in the manner
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Wood Turning Tools & Methods cutting sequentially longer and deeper surfaces until you obtain the approximate outer shape you wish. 6. Before turning the piece around, cut a dovetail shape at the very bottom of the bowl as shown. This dovetail will fit into the holding chuck that will replace the faceplate on the headstock. You need to cut the outer diameter of the dovetail to match the size of the chuck. 7. Similarly, after turning the bowl around and holding it in a chuck (the bottom was cut in a dovetail shaped section). Begin your cuts near the center of the piece, cutting “downhill” towards the center. Enlarge the cut area with each pass, deepening the cut area, until the inner surface of the shape is nearly complete. Remember that cutting should occur on the downhill side of the cutting surface. You can use a pair of double-‐ended calipers to obtain a uniform thickness of the resulting bowl.
Cutting with Skew Chisels 1. These chisels have an angled or skewed cutting surface relative to the axis of the blade. 2. Standard skews have a straight cutting surface resulting from sharpening a rectangular blade while oval skews are cut from a blade that is oval in cross section. 3. Both types are shown in these photos. Both are used in identical manners. They may be used for smoothing surfaces, cutting V’s and for making beads and coves. 4. The toe of the skew chisel is the long point while the heel is the shorter, both at the extremes of the cutting edges. In these sketches, toes are on the left and heels on the right. Smoothing a Surface with a Skew Chisel 1. Cutting will occur with the lathe turning at normal speeds for finishing as shown in the graph on page 11. Smoothing the surface with a skew chisel is undertaken by peeling away the surface in very thin layers. 2. Set the tool rest very close to and parallel with the surface of the work piece and with the top of the rest about ½ inch below the top of the cylinder. 3. Lay the chisel on the top of the rest and let the cutting surface of the blade come to rest on the cylinder without cutting. 4. If cutting to the right, angle the blade towards the right. If to the left, angle the blade to the left, or in the direction of the cut. 5. Slowly raise the handle of the chisel until the cutting edge just barely begins to cut in the lower half of the cutting surface as seen above on the left.
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Wood Turning Tools & Methods 6. Move the blade along the surface to remove material and smooth the surface, again maintaining the cutting action on the lower half of the blade as shown in the middle photo. 7. To smooth the left end of the cylinder, repeat the process but moving from right-‐to-‐left with the blade angled to the left…photo upper right. 8. Continue in both directions until the desired diameter is obtained as measured using calipers. 9. The result should be a very smooth surface finish with no gouges or ripples. Review of Surface Smoothing with a Skew Chisel ü Tool rest parallel to cylinder and ½ inch below top. ü Blade pointed towards cutting direction. ü Cutting surface flat on the surface without cutting. ü Raise handle until cutting starts on lower half of cutting surface. ü Move blade in direction of the cut to remove material in thin layers. Dressing Cylinder End with Skew Chisel
1. The skew chisel may be used to clean up the end of the cylindrical work piece. 2. The tool rest is set close to and parallel with the cylinder, and the height is set just below the center. 3. In this case the cutting surface does not come into contact with the end-‐face of the cylinder. Rather, only the heel of the chisel will contact the work piece with the heel doing the entire cutting process. 4. Set the blade vertically on the rest and bring the chisel face slowly into contact with the surface but without cutting. Then angle the blade slightly away for the face so the heel will come in contact with the work first. 5. Cutting occurs using the heel of the skew with maerial peeling away from the surface immediately at the heel as shown in the photo above to the middle left. Motion of the blade will send the heel arcing upwards then towards the rotational center of the cylinder with the cutting edge angles slightly away from the surface. 6. Starting at the outer surface of the cylinder, begin cutting with the heel as shown in the middle right photo then slowly move the chisel into the work piece end while tracing out an arc from the surface to the center as shown in photo above right. Review of End Dressing with Skew Chisel ü Tool rest close and parallel, top slightly below center. ü Use tool in vertical position, heel down. Page 20 of 27
Wood Turning Tools & Methods ü Angle blade cutting surface slightly away from end surface of work piece. ü Start at outer circumference at end and arc the blade through the piece towards the center. Cutting V-‐Groves with a Skew Chisel 1. Cutting a V-‐groove in the surface of a cylinder is similar to dressing the end except the cut is accomplished using the toe of the blade, not the heel. 2. The tool rest is adjusted close and parallel with the surface, and the height of the rest top is slightly below the centerline of the piece. 3. Set the blade on top of the tool rest in the vertical position and angle the blade slightly away from the direction of the cut. 4. Raise the handle of the tool until the toe begins to cut as shown in left-‐hand photo above. 5. Slowly and carefully raise the handle until the blade begins to cut into the surface. Cut only a small way into the cylinder at first until you gain the feel for the wood and the tool as shown in the center photo. Continue cutting by raising the blade, arcing into the work piece. 6. Reverse the angle of the blade and cut into the surface of the cylinder in the opposite direction so as to meet the previous groove as shown in the rightmost photo above. 7. Repeat the process to left and right continually deepening and widening the cut as you progress. Review of Cutting Vee’s with a Skew Chisel ü Tool rest parallel, close and slightly below centerline. ü Tool on edge to cut with toe. ü Cutting edge angled away from the direction of cut. ü Raise handle to initiate cut, arcing into the piece. ü Reverse process to initiate Vee on the other side. ü Repeat process to achieve desired result.
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Wood Turning Tools & Methods Cutting Beads with a Skew Chisel 1. 1. In the case of cutting a bead, which is the rounded convex crown between two Vee’s, we use the heel of the blade of a skew chisel rather than the toe. Otherwise everything is quite similar to cutting Vee’s. 2. The tool rest is adjusted close, parallel and slightly above centerline of the work piece. 3. The blade is placed on the rest so the cutting surface is touching, but not cutting, the work piece as shown in the leftmost photo above. This is a very similar start to that used to smooth the surface originally with a skew. The blade is angled away from the groove. When ready, begin simultaneously rotating the blade towards the vertical while slightly lifting the tool handle until cutting at the heel commences. 4. Now, move the cutting edge towards the Vee while at the same time beginning rotate the blade away from he surface and to arc the tool into the V-‐groove and downward towards the center. 5. Be very careful during the cut to insure that the wood does not grab the blade causing it to gouge the work piece. Review of Cutting a Bead with a Skew Chisel ü Set tool rest close, parallel, and slightly above work piece centerline. ü Put tool on rest with cutting surface touching work piece surface ü Angle blade in cut direction. ü Begin cut by lifting handle while rotating and arcing from the surface into the bead. ü Repeat until a round shoulder is formed from the surface into the V-‐groove. Sharpening the Skew Chisel Sharpening of the blades is undertaking by holding the cutting edge flat on the grinder’s tool rest that has been adjusted to allow the surface of the blade to lie flat on the stone. Grinding is achieved by moving the blade back and forth across the stone to obtain a smooth and facet less surface and a straight cutting edge. Care just be used with the oval blade to keep it from rocking during the sharpening surface. Rocking will produce an uneven edge where a perfectly straight edge is desired. When one side of the blade is completed, turn it over and sharpen the other side in an identical manner.
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Wood Turning Tools & Methods Parting Tools
There are various styles of parting tools as shown in these sketches. These are used to separate the project from the waste wood. This is true for both spindle and bowl work. They can also be used to produce the dovetail that is used to hold a piece into a chuck. To sharpen the tool, adjust the sharpening rest so when blade is laid flat on the rest the cutting surface the lies flat on the grinding wheel. With the grinder on, move the blade across the rest causing the cutting surface to move smoothly across the grinding wheel. Do this for both sides of the tool to produce a fine cutting edge. The cutting surfaces should be smooth and without facets. Flat Parting Tool for Grooves and Spigots
Starting a Groove with Flat Parting Tool
Cutting Groove with Flat Parting Tool
Parting Tool Making Flute at End
1. The flat parting tool may be used to cut deep, flat-‐sided grooves into a cylinder. The tool rest is adjusted close, parallel and just below center of the work piece. The speed of the lathe is adjusted to normal cutting speeds as shown in the table on page 11. 2. The parting tool is used in the vertical position. Start by placing the tool on the rest so the cutting surface just touches the surface without cutting (photo left). 3. Begin cutting by lifting the handle while at the same time slowly moving the tool into the work piece. Be cautious that the blade does not jam in the groove and alleviate tis possibility by slightly widening the groove as shown in the middle photo above. 4. Continue cutting until the desired depth is obtained as determined by calipers. Be cautious that you don’t cut so deeply that there is insufficient strength left resulting in the piece falling apart. Note that if a work piece is being held in a chuck, you may use this method to “part” a portion of a spindle from the rest by cutting to the center and allowing the end piece to gently fall into your hand. Making a spigot at the End
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Wood Turning Tools & Methods 5. To make a spigot used to hold a work piece in a chuck, use the parting tool to reduce the diameter at the end of the piece as shown in the photo on the previous page. Continue until the desired diameter is obtained, especially to place in a chuck. Use a caliper to determine the result. 6. If you need a flute, or dovetail, on the spigot, simply angle the parting tool slightly into the end and, using the lower corner to make a flute bevel, continue cutting smoothly to obtain the desired result.
Scrapers Scrapers are finishing tools of various shapes and sizes. All have the same characteristic: the cutting surface is almost perpendicular to the surface of the blade, having a cutting surface angle of about 80º as shown in the photos at the right. Their use is to finish off a project to its final shape on either spindle work or bowls and platters. To sharpen the blade on a scraper, place it on the end of the grinding rest close to the wheel, supporting the blade with your finger as shown in the middle photo at the right. Move the blade so the sharpening surface comes fully in contact with the grinding wheel and move the blade smoothly to effect a smooth surface without facets.
Finishing a Bowl or Cup Finishing the Outside of a Bowl with a Square-‐End Scraper 1. Adjust the tool rest just above center and about half an inch away from the face of the bowl held in a chuck (lower photo right). 2. Place the blade flat on the rest and angle the handle up by about 10º above horizontal. 3. Push the blade slowly into the piece until the scraping process begins with the top cutting edge just coming into light contact with the wood and having cutting occur near the center of the cutting edge. 4. The cutting edge should be just below the centerline of the project. 5. Traverse the tool along the surface of the wood keeping the blade perpendicular to its surface so as to maintain cutting near the center of the cutting edge. Note the angle between the scraper cutting surface and the work piece at right.
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Wood Turning Tools & Methods 6. Be careful not to push too hard or the blade will dig into the wood, likely ruining the project. Move the blade completely and smoothly along the bowl to produce a very smooth surface without any torn or projecting bits of grain. Finishing the Inside of a Cup with a Round-‐End Scraper 1. Adjust the rest to just above the centerline and close to the end of the cup held in a chuck. The round-‐edge scraper has no corners so may be used to completely traverse the inner surface without gouging. 2. Place the blade on the rest and insert into the cup until contacting the innermost surface just above center. Work “downhill” from the bottom by moving the blade outward and rotating the handle horizontally to the right along the inner surface of this end-‐grain project. 3. The result should be a very smooth surface without any roughness or torn grains.
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Wood Turning Tools & Methods Summary of Cutting Tools & Methods
ADJUSTMENT INFORMATION FOR VARIOUS TOOLS GOUGES Roughing Gouge Spindle Gouge Detail Gouge Shallow Detail Gouge
Blade Fluted Flat or Oval Flat or Oval Flat or Oval
SKEW CHISELS FOR SMOOTHING Blade Horizontal or Nearly So Standard Oval SKEW CHISELS FOR V-‐GROOVES Blade Vertical or Nearly So Using Toe Standard Oval SKEW CHISELS FOR BEADS Blade Horizontal or Vertical Using Heel Standard Oval PARTING TOOLS Rectangular Diamond Thin SCRAPERS
Nose Angle
Flute Depth 80% 30-‐40° 50% 30-‐40° 33% 40-‐50° 20% 50-‐60°
Rest Height Slightly Below Centerline Slightly Above Centerline Slightly Above Centerline Slightly Above Centerline
60-‐70° 60-‐70°
~½ inch below top ~½ inch below top
60-‐70° 60-‐70°
Slightly below center Slightly below center
60-‐70° 60-‐70°
Slightly above center Slightly above center Slightly below center Slightly below center Slightly below center Slightly above center
Flat Diamond Flat Flat
75° 75° 75° 10°
GOLDEN RULE. Always cut downhill. 1. 2. 3. 4. 5.
Start cutting by putting cutting surface on the wood without cutting. Angle handle away from the direction of cut. Rotate flutes in direction of cut. Begin cutting by slowly raising the handle until cutting occurs. Adjust your cutting depth by raising or lowering handle to suit your comfort level with both the tool and the material.
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Wood Turning Tools & Methods Rules of Sharpening
Tools should be sharpened frequently to insure a smooth cutting edge and good cut on the work piece. Cutting surfaces must be clean and smooth and not broken into different surface segments or facets as if sharpening piecemeal. Note especially the photos of sharpened surfaces on page 6. It is obvious from these that the sharpening was accomplished in a single turning motion with the tool kept at a fixed angle relative to the wheel. This takes practice and can be costly in lost tool material but is necessary to perform clean turning. Be sure the grinding wheel is kept clean and free of imbedded metal (grey specks) by cleaning the stone with a dressing tool when necessary.
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