Charles Neil Dovetail Jig Instructions

Transcription

1 Charles Neil Dovetail Jig Instructions Thank you for purchasing the Charles Neil (CN) Dovetail Jig. This is an easy to use and flexible jig for cutting through dovetails. These instructions complement the DVD that is included in the CN Dovetail Jig kit. The kit includes: metal jig plates for cutting tail and pin boards, dovetail & straight bits (of the sizes purchased), DVD and these instructions. A wooden backer board is needed and may be purchased separately or you may make one. Thank You, Charles Backer Board: The metal pin and tail jigs are mounted on backer boards. They are made as a sandwich with the outside boards having the grain running vertically. The middle board has the grain running along the length to provide stability. The outside board can be glued up from multiple boards with their grain running vertically. Any hardwood can be used with Poplar being a good choice. Do not use MDF as that is hard on your bits and they may dull prematurely. The CN Dovetail Jigs The metal pin and tail jigs are screwed to the backer boards. The tail jig is screwed on and not changed. The pin jig is screwed onto the backer board and will be adjusted for the thickness of board being cut. The pin board has scribe marks on it for aligning the jig depending on the thickness of the wood being cut. The setup will be described later in these instructions.

2 A Typical Board Alignment The CN dovetail jig is used to cut through dovetails (pins and tails) to make corner joints for object like drawers and boxes. A typical alignment of the boards is shown here. It is a good idea to label all the boards so you do not get confused. You can even go so far as to label the inside corners of the boards so you ensure that the correct corners line up when you mark the pin locations from the tail board, as described later. When is a pin not a pin.or, the real story about the mysterious half pin! Both ends of the tail board have what are called half pins cut into them. Most people think of a half pin as one-half the dimension of a full pin. If a full pin is ½ then a half pin must be ¼. NOT TRUE! A half pin is actually called a half pin because it is only cut on one side the other side is straight. It can have any size. In fact, most half pins are cut almost the same size as a full pin because they would look funny if they were too small and could potentially break off. Now you know the real story! These instructions describe a process where the tail board is cut first. You can cut the pins first but that is left as an exercise for you to pursue! The diagram shows marks on the tail board for halfpins on either end of the board and estimates where pins will go between the half-pins. There is also a line indicating the thickness of the pin board.

3 The tail board can be placed in a bench vice with either side facing out. It does not matter for the tail board. The edge of a jig finger is placed along the pencil line for one of the half-pins. A stop block can be screwed to the backer board to facilitate cutting subsequent half-pins. The router with the dovetail bit is then placed onto the jig to set the depth of cut. The bottom of the dovetail bit is set to the bottom of the pencil line. Note: The small pre-cut straight bit can also be optionally used in a second router to remove a small amount of wood and lessen the stress on the narrow neck of the dovetail bit. The pre-cut bit should be set just above the pencil line, leaving the line. The dovetail bit will make the final, clean cut to the line. The spacing of the jig fingers are designed so uniform pin settings are possible without moving the jig. Uniform spacing without moving the jig are possible for board widths of 1 7/8, 3 5/8, 5 3/8, 7 1/8, 8 7/8, 10 5/8, 12 3/8 and 14 1/8. For example, if you have a 5 3/8 board you can set the jig to cut the 2 half-pins and 2 uniformly spaced intermediate pins and cut them all without moving the jig between cuts.

4 What happens if your board is not one of these specific dimensions? You can easily create uniform (or non-uniform, if desired) spaced dovetails by drawing your half-pin on one side and set it up with a stop block as described earlier. Cut both half-pins. Then center the fingers between these half-pins using the scrap wood block technique as described on the video. Cut the remaining pins. What if the board is longer than the jig? Mark the location of the last finger with a pencil and move the jig over and align a new finger to that mark. Just keep moving the jig and continue making cuts!! The DVD describes a technique to set the positions of the jig for cutting the intermediate pin locations. The jig can be moved a variety of times to cover whatever spacing you desire. Remember - The spacing of the intermediate pin locations do not have to be uniform. They can be staggered and the jig moved to easily accommodate their locations. The diagram shows a completed tail board. Transferring pin locations from the tail board to the pin board: The pin locations are transferred from the tail board to the edge of the pin board. The DVD will show how to hold the pin board in your bench vice and lay the tail board on top. Use a pencil to draw lines along the previously cut tails. Be sure to align the outside of each board correctly refer to the diagram. Be careful not to switch the direction of either board by mistake so that the pins are cut correctly on each end of the pin board.

5 This is what the edge of the pin board should look like after tracing the outlines of the pins with a pencil. The pin board can now be positioned in the pin jig. The outside of the pin board will be facing outwards. The front edge of the pin board should align with the mark on the jig associated with the dovetail bit size (eg; 5/8 bit). The jig fingers should be set to just split the line of your pencil marks. A close up of this is shown later in these instructions. Once set, you can move and clamp the pin jig to cut the wood out of the various tail locations. Before cutting, you need to set the depth of the straight bit. Draw a line on the pin board the thickness of the tail board. Then set the straight bit to the bottom of the pencil line, as shown.

6 Now that the router and bit are ready to make a cut, set the jig onto edge of the pin board with the fingers aligned with your pencil marks. The fingers should split the line for best alignment. This means that part of the pencil line is visible and part is under the metal finger. Try to visualize that the pencil mark was drawn on the waste side of the wood next to the pin. So, if some pencil is still visible after cutting, then the pin shouldn t be too small!! But, what if the joint is too loose or tight? You can adjust the location of the metal pin jig to change the fit of the dovetail joint. Loosen the jig screws and move the metal jig forward to tighten the joint or back to loosen the fit. Here in the pin board after being cut.

7 Finally, align the pin and tail boards and put them together. The joint should go together with hand pressure or light taps with a mallet. Do not hammer away with a mallet to drive the joint together. You may split one of the boards (normally the tail board) or at a minimum you would probably starve the joint of glue by forcing all of the glue out of the joint. This is how the joint should look after assembly. Fool the experts! As a final touch, you could place a scribe line on each board and, viola!, Hand-cut dovetails!! Have Fun! Charles