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How to Make Small Carving Tools

How to Make Small Carving Tools

By Mike Burton


I learned to make small carving tools out of necessity. I do intricate, detailed carvings, and the selection of small carving tools in catalogs is painfully limited. Solution? I started making my own. Not only can I make unusual sizes and shapes, but the handles are shaped to fit my hands. Plus, these tools are very inexpensive. Give them a try—there’s nothing like the feeling of using a tool that you have made yourself.

 

Supplies and Equipment

The raw material of these carving tools is drill rod, a tool steel available in various diameters. You can buy it from local machine shops or industrial suppliers for about $2.50 for an 18-in. length.

You’ll also need a metalworking vise, but it doesn’t have to be fancy. Be sure it has a flat “anvil” area for flattening the rod. My vise cost $15.

For heating the rod, use a MAPP gas torch ($35 at home centers). This is just like a propane torch except it’s designed for MAPP gas, which burns hotter than propane. You can’t use MAPP gas in a common propane torch.

A selection of files, small grinding stones and a small diamond hone will be needed for shaping the tools.

 

Working Safely

The flame from a MAPP torch is even more dangerous than the flame from a propane torch, so follow these safe work habits.

■ Prepare a safe work area. Remove sawdust, rags, finishes, wood scraps and any other flammables from your work area.

■ Keep the lights down low. This makes it easier to see the flame, and easier to judge the color of the heated rod.

■ Avoid tip-overs. The torch is top-heavy, and easy to tip over. I found an old, widemouth coffee pot that the cylinder of my torch fits into. When I’m not using it, the torch rests steady in the pot. You can rig up something similar.

■ Wear safety glasses. Tiny pieces of hot steel and scale can be dislodged at just about any stage in this project. Always wear your glasses.

■ Manage the heat. Whenever possible, work on long (18-in. or so) pieces of rod. Cut the finished tool off the end. If you need to heat a short piece, grip it with locking pliers. Don’t try to use drill rod thicker than 3/16 in.; MAPP gas won’t be able to get it hot enough.

 

The Basic V-Tool

The simplest small tools are filed directly into the drill rod, without any forging. This small V-tool is a good example.

Click on any image to view a larger version.


1. Form a v-shape with a triangular file on the end of an 18-in. piece of 5/32-in. drill rod. Bending the tip of the rod will give you room to work.


3. Form the cutting edge with a file and diamond hone, then straighten the shank. If this is the only tool you’re making, proceed to heat-treating (Photos 10 and 11) and attaching a handle (Photo 12).

2. Refine the inside with a diamond hone ($10). You may need to file down the plastic sides of the hone so it will fit in the tiny V.

 

Gouges, Chisels, and Skews

Very small gouges, chisels and skews can be filed directly from drill rod, just like the V-tool, using a small rat-tail or flat file. Refine the inside with a rolled-up piece of 320- to 600-grit sandpaper or a diamond hone. Larger tools need to be forged, as shown below.


4. Flatten the tip of the drill rod for larger tools. Heat the tip to a bright red glow with a MAPP torch, quickly place it on the anvil section of the vise, and hammer it flat.

5. For wider tips, first thicken the end of the drill rod by heating it to bright red and pounding the end to “upset” (compress) it. You can make the rod half-again thicker this way. After upsetting, heat the tip again and flatten it.


6. Make a crease to further widen the tip by hammering it against the edge of the vise. For more width, make several creases in a fan pattern. Heat the rod again, and hammer out the creases.

7. Use a swage to hammer the heated rod into a gouge shape. The swage is made from a length of 3/16-in. drill rod and a large bolt. The rod fits on a groove filed into the head of the bolt with a 1/4-in. rat-tail file. Sandwich the red-hot tool blank between the rod and the groove; then hammer.


8. Use a socket as an anvil to open up or form gouge shapes. Different socket sizes can be used for gouges of different shapes. This is also a good method for making curved detailing knives.

9. Grind the inside to refine the shape of a gouge using a cone-shaped grinding wheel in an electric drill or rotary tool. Roughly form the bevel, but don’t sharpen yet. The tool must first be heat-treated.


10. Slow cooling on an electric burner (annealing) will reduce stresses built up in the metal during forging. Heat the first 1/2 in. of the tool tip bright red, keep it red for 30 seconds, then place between the coils of a burner set on high. Every 10 minutes, lower the heat until the tool is cool.


12. Attach the handle last Heat the handle end of the tool and hammer the last 1/2 inch or so square to prevent twisting. Drill a hole in the handle, add a bit of carpenter’s glue and pound the handle onto the tool. For bent tools, hold the shank with locking pliers and pound on the pliers. Give the bevel a final grind, sharpen, and you’re ready to carve.

11. Tempering produces a hard, durable edge. Heat the tool tip to a bright glow for 30 seconds, then plunge into cold water. Polish the end of the tool to a mirror shine with fine sandpaper or emory cloth. Heat the tool slowly, keeping the flame about an inch below the cutting edge. When the edge turns a medium straw color, plunge it into cold water. (You may want to practice this!)




This story originally appeared in American Woodworker April 1999, issue #72.

April 1999, issue #72

Purchase this back issue.

 

 

Creating CNC Textures

Creating CNC Textures

By Randy Johnson

CNC routers are opening up lots of new ways to create textures in wood. Here are my three favorite ways of creating textures using a CNC. Th e fi rst method uses the repetition of shapes to create a design that is routed using one or more bits. If you enjoy doodling patterns, this is a technique that you will enjoy. Th e second method uses programming built in to the design soft - ware to generate a texture design that simulates a handcarved pattern. Th e third texturing method starts with a photograph and converts the light and dark areas into the routing paths. Each method has a few basic rules to follow, but add some imagination and the variations you can achieve are virtually limitless. I used Vectric Aspire CNC design soft ware to create the textures for this article, but other soft ware packages such as ArtCAM and EnRoute can also be used to create textures.


Shape-Based Textures


Shape-based textures are created by repeating a pattern of either asymmetrical or symmetrical shapes. Patterns can be hand-drawn or drafted with a CAD program such as Google SketchUp. Hand drawn designs need to be scanned or digitally photographed so they can be imported into the CNC design program. CNC design programs are also capable of creating shape-based patterns. One creative aspect of this type of texturing is that you can rout on the lines or between them to achieve different effects. I routed the crackle texture shown below using a 1/4" dia. 60° v-bit. It took about 60 minutes to carve the design into this 10" cherry lid. The dome shape of the lid was created first using a 1/4" dia. ball nose bit.

Click any image to view a larger version.




Software-Based Textures


Using the built-in texturing program that comes with most CNC design software packages is an easy way to create a simulated hand-carved texture. As shown in the program window to the left, there are several options to choose from when designing this type of texture. Adjusting these variables enables you to create a wide variety of simulated hand-carved textures, ranging from those with long, closely spaced cuts, to those with short, widely spaced cuts— and anything in between. Once the options are selected, the program creates a semi-random pattern of lines (see middle image below) for the router bit to follow. I used the settings shown here to create texture on the walnut lid show below. I used a 1/4" ball nose bit to create the texture, but other profiles such as straight bits or v-bits can also be used, expanding your options even further. It took about 60 minutes to carve the texture shown below.





Photo-Based Textures


Another way to create a CNC texture is to start with a photo. Not all photos work equally well, however. That’s because the CNC design software reads the light areas as high points and the dark areas as low points and tells the CNC router to carve accordingly. A good photo image is one that is evenly lit without long shadows, but yet has good contrast. As you can see in the alligator skin photograph below, the highlights accent similar areas, while the dark areas are consistent in the rest of the photo. This type of photo will create a texture that closely resembles the contours of the original. Carving a photo-based texture requires the use of a small ball nose bit to attain the details. For the design below, I first roughed out the texture and dome shape of the lid with a 1/4" ball nose bit and then carved the final shape and details using a 1/8" ball nose bit. It took about two hours to do the final routing and about the same amount of time for the roughing passes.




Texture Variations


Shape-based textures can take many forms, from low relief to high relief, and from subtle to bold. The three textures above are just a sampling of options that are possible with this approach to designing textures for the CNC. The one on the left was created using a collection of small circles that were then routed around with a 60° v-bit. The middle design is simply an array of concentric squares, while the one on the right uses a grid pattern made with a 120° v-bit.


Software-based textures are the easiest—and often the fastest—to create, and can be run on top of a shape (left), around a shape (middle), or overlapping in different directions (right). These options allow you to be selective and creative in where and how the texture is applied. Using different bits will also expand the variations you can create with this method of texturing.


Photo-based textures are an easy way to simulate existing textures—as seen in these three examples. The weathered end grain (left) shows a surprising amount of detail, as does the cloth texture (right). The stones (middle) create an interesting pattern, although they are rendered quite flat. Additional depth can be added to the stones through the use of other modeling tools, if so desired. The thing to remember about creating textures from photos is to always start with a photo that has even contrast.




This story originally appeared in American Woodworker April/May 2012, issue #159.

 

 

V-Carve Inlay

V-Carve Inlay

A simple method for creating precision inlays from almost any design.

By Randy Johnson

V-carve inlay takes advantage of a CNC’s ability to precisely rout matching parts. In this case the parts are made as opposites and fit together to create a precise-fitting inlay. The sides of the parts are beveled and fit together like the lid on jack-o’-lantern pumpkin. The technique is surprisingly easy to learn and implement, in spite of the fact that it would be nearly impossible to create these parts any other machine or by hand. It’s truly a technique that’s unique to the CNC. The fact that almost any design can be used, opens up many creative opporutunites. As CNC’s become more common in small shops, I fully expect to see v-carve inlays showing up on furniture in some intersting ways.


Step 1

Layout your design. Almost any design will work, but all individual parts of the design must be made with a single continuous line so the router has a complete path to follow. A shape that is open-ended or has a gap in the line will not be recognized by the v-carving program. I designed this pattern (right) in about 15 minutes, using V-Carve Pro from Vectric. I started with a single “petal” shape and then copied it using a function called “copy circular array” to create the 12 identical shapes. There’s no need to shy away from sharp details such as corners or points. V-carving programs excel at capturing such detail. For more information on v-carving see “V-Carving in 10 Easy Steps”.

Click any image to view a larger version.


Step 2

Set the flat area cutting depth for the pocket portion of the inlay to .15”. Setting the depth to this dimension provides clearance under the inlay to ensure that it doesn’t bottom out in the pocket. The dotted line represents the location of the pattern, which in this case is the surface of the board.


Step 3

Set the cutting depth for the inlay in two stages. First set the “start” cutting depth at .10” and then the cutting depth at .10”. Setting the cutting depths in this fashion will ensure a small amount of clearance between the inlay and pocket boards. The dotted line also represents the elevation or the location of the pattern in the board.


How it works

The angled shoulders of the inlay and pocket intersect to create a tight, wedged fit. The cutting depths for these parts are set to provide clearance between the parts (Steps 2 and 3). The excess top portion of the inlay is removed down to the dotted line to reveal the final pattern (Step 7).


Step 4

Rough rout the background and wide areas with a straight bit. Rough routing removes the majority of the wood in the large areas. This reduces the amount of material the v-bit needs to remove in Step 5 and shortens the overall machining time for the project by about 15 minutes. I also routed the cutout profile around each part at this time, although the parts are still attached to the outer boards with tabs. It took about 20 minutes to rough rout and profile this design.


Step 5

V-carve the design details with a 90° v-bit. Notice that the inlay on the left is a mirror image of the design on the right. They must be opposites in both relief and orientation in order to fit together. This is important to remember when laying out and programming your design. This step took about 25 minutes.


Step 6

Apply glue to both parts. A small brush makes it easy to get the glue into the v-carved areas. The inlay portion has been trimmed to rough size on the bandsaw.


Step 7

Tighten the clamps lightly at first and then add a little pressure to each clamp until they are all fully tightened. Applying uneven pressure can cause misalignment of the parts. Leave clamped until glue is completely dried.


Step 8

Rout off the excess material to reveal the final inlay. The ability to control the cutting depth in increments as small as .001” makes it easy to precisely remove the extra material. For this project I used a 3/4” straight bit and programmed it to remove the majority of the material in 1/8” deep passes until it got to within .02” of the surface. I then continued with .005” passes until the bit removed just enough material to expose the inlay and get rid of the dried glue. This step took about 10 minutes.




This story originally appeared in American Woodworker August/September 2011, issue #155.

 

 

V-Carving in 10 Easy Steps

V-Carving in 10 Easy Steps

By Randy Johnson

V-carving is one of the simplest ways to create attractive carvings on a CNC router. With special software and a little practice, it’s possible to transform almost any lettering style or 2D design into a carving that requires only minimal cleanup before finishing. I use V-Carve Pro software from Vectric, but the steps are similar with other v-carving programs. The software tells the machine to raise the bit at the inside corners; the machine then uses the tip of the v-bit to create corners that are clean and crisp—as opposed to the rounded corners made by a handheld router guided by a template. For more examples of v-carving visit AmericanWoodworker.com/CNC.


Step 1

Layout your design. All it takes is a simple hand sketch or photograph. This can be imported directly into the program and then outlined using the drawing tools in the v-carve design program. Since both letters and shapes can be carved, there are not many limits to the kinds of designs you can v-carve. You also have the choice of carving on the inside or outside of letters or shapes.

Click any image to view a larger version.



Step 2

Make sure all shapes are closed. This is one of the cardinal rules of v-carving design. A circle, square or the outline of an object qualifies, but a single line or parallel lines with open ends will not work. The v-carve programs need a continuous outline to follow. Some outlines may look continuous, but even a little break in the line will cause problems. Fortunately, v-carve programs are able to recognize shapes that have small openings and will automatically close them for you.



Step 3

Set the cutting depth for the background of your carving and the inside of the letters (as needed). This cutting depth is mainly a design decision, and of course it cannot exceed the thickness of your board. The cutting preview (example at right) will show you how your chosen cutting depth looks.



Step 4

Select your router bits. Use a straight bit first to rout flat areas. The diameter of this bit determines how much cleanup the v-bit will need to do inside a corner. A large diameter straight bit removes material faster but leaves more for the v-bit to cleanup. A small diameter straight bit leaves less material inside a coner but takes longer to clear the flat areas. I typically use a 1/4" diameter end mill for drawer front or cabinet door carvings.

The three most common v-bit angles are 60°, 90° and 120°. I prefer using a 90° and 120° v-bit for wide or large letters and a 60° v-bit for small or fine letters. If possible, I also prefer to use a v-bit with a cutting radius that’s slightly wider than the width of the final bevel. This allows me to make one final cleanup pass (if needed) to remove any step marks left by the initial passes.



Step 5

Create cutting paths for the recessed background and export them from your v-carving design program to your CNC machine. The cutting paths (shown above in red with tiny arrows) show the areas that will be routed. Here I’m using a 1/4" end mill bit to rout the flat background area. I’m accomplishing this with 1/8" wide passes (shown by the distance between the red lines). This dimension is referred to as the “stepover” measurement. The cutting depth per pass can also be programed, as can the feed (travel) rate of the router, expressed in inches per minute.



Step 6

Rout the recessed background area. To ensure a smooth background on this plaque, I used a couple techniques. First, I routed the background area in two .06" (about 1/16") deep passes, plus a light .01" pass to reach the final depth of .013". Three passes take more time than one, but create a surface that requires only light sanding. Second, I programed the router to cut with the grain (see Step 5). This reduces sanding, too. Milling the background for this plaque took about 20 minutes.



Step 7

Create cutting paths for the bevels around the shapes (the hand plane and perimeter rectangle in this case) and export them to your CNC machine. For this design, I will be using a 90° v-bit, which produces a 45° bevel. The shaded areas above the handle and below the depth-adjustment knob are closely-spaced tool paths where the v-bit needs to make many close passes to mill the background flat. These areas are too narrow for the 1/4" end mill bit to get into.



Step 8

Rout the bevels around the shapes. This requires removing the straight bit and installing the appropriate v-bit. I used a 1/2" diameter 90° v-bit. It has a 1/4" tall bevel—more than enough for the carved bevel, which will be only 1/8" tall. This step took about 20 minutes to rout. Except for some light hand sanding and a little touch-up with a carving chisel, this part of the carving is now complete.



Step 9

Create tool paths for the lettering. This requires a separate step because I’m changing to a 60° v-bit. I prefer a 60° bit for small letters such as these because it creates a deeper, more distinctive v-groove than a 90° bit. The tool paths above show how v-carving requires two lines to carve between. The two lines are parallel in these letters, but they can be any shape or spacing. For example, the outline of the hand plane and outer rectangle represents the pair of lines that were used to create the hand plane carving.



Step 10

Rout the lettering. Notice that “No. 4” is routed into the surface of the plane whereas as the logo is carved into the background. I programed the difference in cutting depth into the cutting paths while designing the plaque. This final carving step took about 8 minutes. To view a video on how I designed and machined this plaque from start to finish, visit AmericanWoodworker.com/CNC.




This story originally appeared in American Woodworker April/May 2011, issue #153.

April/May 2011, issue #153

Purchase this back issue.