Patent Publication Number: US-11389988-B2

Title: Method and apparatus for cutting dadoes

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to the field of woodworking tools. More particularly, the present disclosure relates to a jig for cutting both open and blind dadoes. Specifically, the present disclosure relates to an adjustable jig for cutting dadoes allowing quick and repeatable dado cutting to the exact width needed without measurement. 
     BACKGROUND 
     Background Information 
     As used in woodworking, a dado is a rectangular crosscut made into a board or other workpiece to make a joint with a second board. Dadoes are commonly used to join two pieces of wood, such as shelves and shelving units or the like. In its most basic form, a dado is a cut into the face of one board to match the thickness and width of a second board which is then inserted into the dado in the first board on its edge. 
     Whether a result of imported wood, conversions between metric and imperial measurement systems, or variable dimension measurements across lumber brands, it is now commonplace that plywood and other sheet goods do not measure exactly to their nominal dimensions. Further, the actual dimensions of plywood and other sheet goods tend to vary widely across brands, sheet type, and country of origin. It is therefore common that two pieces of wood may be marked as having the same nominal dimensions, but may in fact have two different actual dimensional measurements. When using such wood stock in creating a workpiece, particularly those workpieces that are desired to have a fine finish and uniform appearance, it is difficult to cut dadoes that are a uniform fit given the variability of the measurements of the wood stock. 
     Current practices for cutting dadoes involve taking multiple measurements and making very detailed plans to account for varying thicknesses of each piece of stock being used. This is time-consuming and introduces significant opportunity for error to be made in that a measurement error of even a small fraction of an inch or a few millimeters can result in a dado that is too small to accept the second pieced of stock or alternatively is too big and includes slop and movement of the stock piece therein. Alternatively, in the past woodworkers have used undersized router bits to cut dado grooves in small increments across several passes and hoped that the groove is sized to fit the second board. In this instance, multiple passes are made and the woodworker attempts to err on the side of the dado being too small as more wood can always be removed from the dado to accommodate a thicker board. However, it is difficult to keep these cuts exact relative to the width of the stock, particularly when that width may not be uniform across all stock pieces being used. 
     SUMMARY 
     The present disclosure addresses these and other issues by providing a dado jig that may be adapted for use with any thickness of wood stock to allow quick and accurate cutting of dadoes to fit the thickness of the stock piece exactly. The present disclosure further provides a method of use for a dado jig to cut both open and blind dadoes with stock of varying thicknesses without the need to measure that thickness. 
     In one aspect, an exemplary embodiment of the present disclosure may provide a jig for cutting dadoes comprising: a first rail having a first end orthogonally fixed to a first end plate and a second end longitudinally spaced apart from the first end and defining the longitudinal length of the first rail therebetween; a second rail having a first end movably connected to the first end plate and a second end longitudinally spaced apart from the first end and defining the longitudinal length of the second rail therebetween, the second rail being movable relative to the first rail in a transverse direction orthogonal to longitudinal length of the first and second rails; a second end plate moveably connected to the second end of the first rail and the second end of the second rail, the second end plate being movable relative to the first end plate along the longitudinal length of the first and second rails; a first edge guide connected to the first rail; and a second edge guide connected to the second rail, the first and second edge guides operable to guide a router bit for cutting a dado in a workpiece. 
     In another aspect, an exemplary embodiment of the present disclosure may provide a method of cutting dadoes comprising: aligning a first end plate of a dado jig against a first end of a first board and securing the first end plate thereto; aligning a second end plate of the dado jig against a second end of the first board longitudinally opposite the first end plate and securing the second end plate thereto; positioning a second board orthogonal to the first board with a side of the second board between a first rail extending longitudinally between the first end plate and the second end plate of the dado jig and a second rail extending longitudinally between the first end plate and the second end plate of the dado jig; moving the second rail transversely relative to the first rail to contact a first face of the second board with the first rail and a second face of the second board with the second rail; securing the second rail in position relative to the first rail; removing the second board from between the first and second rails; cutting a dado in the first board between the first and second rails of the dado jig. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       A sample embodiment of the disclosure is set forth in the following description, is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims. The accompanying drawings, which are fully incorporated herein and constitute a part of the specification, illustrate various examples, methods, and other example embodiments of various aspects of the disclosure. It will be appreciated that the illustrated element boundaries (e.g., boxes, groups of boxes, or other shapes) in the figures represent one example of the boundaries. One of ordinary skill in the art will appreciate that in some examples one element may be designed as multiple elements or that multiple elements may be designed as one element. In some examples, an element shown as an internal component of another element may be implemented as an external component and vice versa. Furthermore, elements may not be drawn to scale. 
         FIG. 1  ( FIG. 1 ) is a top left perspective view of a dado jig according to one aspect of the present disclosure. 
         FIG. 1A  ( FIG. 1A ) is a close up perspective view of the area identified in  FIG. 1  according to one aspect of the present disclosure. 
         FIG. 1B  ( FIG. 1B ) is a close up perspective view of the area identified in  FIG. 1  according to one aspect of the present disclosure. 
         FIG. 2A  ( FIG. 2A ) is a bottom left perspective view of the area from  FIG. 1A  according to one aspect of the present disclosure. 
         FIG. 2B  ( FIG. 2B ) is a bottom left perspective view of the area from  FIG. 1B  according to one aspect of the present disclosure. 
         FIG. 3  ( FIG. 3 ) is a top plan view of a dado jig showing dimensions thereof according to one aspect of the present disclosure. 
         FIG. 4  ( FIG. 4 ) is an exploded view of a guide bushing for use with a dado jig according to one aspect of the present disclosure. 
         FIG. 5  ( FIG. 5 ) is a side elevation view of a router and guide bushing with the router and guide bushing rendered in a partial cross-section according to one aspect of the present disclosure. 
         FIG. 6  ( FIG. 6 ) is a top left perspective operational view of a dado jig installed on a first board according to one aspect of the present disclosure. 
         FIG. 7  ( FIG. 7 ) is a top left perspective operational view of a dado jig installed on a first board with a second board inserted therein according to one aspect of the present disclosure. 
         FIG. 8  ( FIG. 8 ) is an overhead plan operational view of a dado jig installed on a first board according to one aspect of the present disclosure. 
         FIG. 9  ( FIG. 9 ) is an overhead plan operational view of a dado jig installed on a first board showing a router prior to making a dado cut according to one aspect of the present disclosure. 
         FIG. 10  ( FIG. 10 ) is an overhead plan operational view of a dado jig installed on a first board showing a router in the process of making a first side of a dado cut according to one aspect of the present disclosure. 
         FIG. 11  ( FIG. 11 ) is a side elevation view of router and a dado jig in use on a first board, with the dado jig and first board rendered in cross-section according to one aspect of the present disclosure. 
         FIG. 12  ( FIG. 12 ) is an overhead plan operational view of a dado jig installed on a first board showing a router having completed the first side of a dado cut according to one aspect of the present disclosure. 
         FIG. 13  ( FIG. 13 ) is an overhead plan operational view of a dado jig installed on a first board showing a router in the process of making a second side of a dado cut according to one aspect of the present disclosure. 
         FIG. 14  ( FIG. 14 ) is an overhead plan operational view of a dado jig installed on a first board showing a router having completed the first side of a dado cut according to one aspect of the present disclosure. 
         FIG. 15  ( FIG. 15 ) is a top left perspective view of a first board with an open dado cut formed therein according to one aspect of the present disclosure. 
         FIG. 16  ( FIG. 16 ) is a top plan operational view of a first end of a dado jig according to one aspect of the present disclosure. 
         FIG. 17  ( FIG. 17 ) is a top plan operational view of a second end of a dado jig according to one aspect of the present disclosure. 
         FIG. 18  ( FIG. 18 ) is a top left perspective view of a first board with a blind dado cut formed therein according to one aspect of the present disclosure. 
     
    
    
     Similar numbers refer to similar parts throughout the drawings. 
     DETAILED DESCRIPTION 
     With reference to  FIGS. 1-3 , an exact width dado jig is shown and generally indicated at  10  and hereinafter referred to as jig  10  or dado jig  10 . Jig  10  may have a first rail  12 , a second rail  14 , a first end plate  16 , and a second end plate  18 . Jig  10  may have a first end  20  spaced apart from a second end  22  and defining a longitudinal direction therebetween. Jig  10  may also have a first side  24  spaced apart from a second side  26  and defining a transverse or horizontal direction therebetween. Jig  10  may have a top side  28  spaced apart from a bottom side  30  and defining a vertical direction therebetween. Generally speaking, top side  28  of jig  10  is the side facing upwards while jig  10  is in use and bottom side  30  is the side facing downwards and sitting on a face of a board when jig  10  is in use, as described further herein. 
     First rail  12  may have a first end  32  spaced apart from a second end  34  in the longitudinal direction. According to one aspect, first end  32  may coincide with and/or define first end  20  of jig  10 , while second end  34  of first rail  12  may coincide with and/or define second end  22  of jig  10 . First rail  12  may also have an outer side  36  which may be transversely spaced apart from an inner side  38 . Outer side  36  may be the side of first rail  12  facing away from second rail  14  while inner side  38  may be the side of rail  12  facing towards second rail  14 . First rail  12  may further include a top surface  40  generally oriented towards top side  28  of jig  10  and a bottom surface  42  generally oriented towards the bottom side  30  of jig  10 . 
     First rail  12  may have a first longitudinal adjustment slot  44  defined therein for longitudinal adjustments of jig  10  as described further below. First longitudinal adjustment slot  44  may include a longitudinal adjustment knob  46  and an alignment screw  47 . First longitudinal adjustment slot  44  may extend along a portion of first rail  12  from nearby second end  34  towards first end  32 . 
     First rail  12  may further include a ruler channel  48  containing a sliding ruler  52  therein. Ruler channel  48  may contain ruler  52  via a ruler thumb screw  50  that may be tightened or loosened as desired to prevent ruler  52  from being removed from ruler channel  48  accidentally. Ruler channel  48  may be a groove or depression integrally formed into first rail  12  and extending the longitudinal length thereof. 
     Ruler  52  may be removable from ruler channel  48  and may include an offset notch  53  and an offset scale  54  for use in setting the appropriate depth of a router bit  170 , as discussed below. Ruler  52  may also include a second scale  55  for use in setting the position of stop members  100  and  136  when cutting a blind dado  206 , also discussed further below. 
     First rail  12  may have a reference line  56  marked on the top surface  40  adjacent to ruler channel  48  and precision aligned with the second end  84  of first end plate  16  as discussed further below. According to one aspect, reference line  56  may be painted or otherwise applied, such as through a sticker or the like, to top surface  48 ,  40  of first rail  12 . According to another aspect, reference line  56  may be etched, scored, or the like into top surface  40  of first rail  12 . 
     First rail  12  may further include an edge guide  58  which may be mounted to an edge guide mounting flange  60  formed in the bottom surface  42  of first rail  12 . Edge guide  58  may be a removable and replaceable component that is adhered to bottom side  42  of first rail  12  via adhesive, magnets, or any other temporary connection. According to another aspect, edge guide  58  may be more permanently affixed to bottom surface  42  of rail  12 . According to another aspect, edge guide  58  may be a flexible material and may include one or more features to allow it to grip the edge guide mounting flange  60  to keep it secure against bottom surface  42  of first rail  12 . Edge guides  58  may be constructed of plastic, rubber, or other synthetic materials that may be utilized to insure dadoes are cut to the appropriate position as discussed further herein. Bottom surface  42  may have an edge guide removal notch  62  defined therein (best seen in  FIG. 2B ) which may facilitate the removal and replacement of edge guide  58  as necessary. 
     Second rail  14  may likewise include a first end  64  generally corresponding to first end  20  of jig  10  and a second end  66  generally corresponding to second end  22  of jig  10 . First end  64  and second end  66  of second rail  14  may be spaced apart along the longitudinal direction. Second rail  14  may further include an outer side  68  and an inner side  70 . As with first rail  12 , outer side  68  of second rail  14  may be the side facing away from first rail  12  while inner side  70  of second rail  14  may be the side facing towards first rail  12  when jig  10  is installed and in use. Second rail  14  may have a top surface  72  generally oriented to the top side  28  of jig  10  and a bottom surface  74  generally oriented to the bottom side  30  of jig  10 . 
     Second rail  14  may have a second longitudinal adjustment slot  76  defined therein with a two-way adjustment knob  78  installed therethrough. Two-way adjustment knob  78  may be utilized in both longitudinal and horizontal (transverse) adjustments of jig  10  as discussed further herein. Similar to longitudinal adjustment knob  46 , two-way adjustment knob  78  may be generally located towards second end  66  of second rail  14 . Second longitudinal adjustment slot  76  may extend from nearby second end  66  of second rail  14  generally towards first end  64  of second rail  14 . Second rail  14  may further include a horizontal adjustment knob  80  generally located at or near first end  64  of second rail  14 . 
     First and second rails  12 ,  14  may be constructed of any suitable material. According to one aspect, rails  12 ,  14  may be formed of phenolic which is a slick, hard, synthetic material with a long-life span that is highly durable and resistant to cuts and abrasions that may occur over the life of jig  10 . According to another aspect, rails  12 ,  14  may be made of any suitable material including, but not limited to, metals such as steel or aluminum or high density, high durability synthetic materials such as plastics or resins. First and second rails  12 ,  14  may be formed using any suitable manufacturing method, including extrusion, milling, induction molding, or the like. 
     The operation and adjustments of rails  12  and  14  of jig  10 , utilizing first and second longitudinal adjustment slots  44 ,  76 , longitudinal adjustment knob  46 , two-way knob  78 , and/or horizontal adjustment knob  80 , will be discussed further below with reference to the operation and use of jig  10 . 
     With continued reference to  FIGS. 1-3 , but with particular reference to  FIGS. 1A through 2B , first and second end plates  20 ,  22  will now be described. First end plate  16  may include a first end  82  generally corresponding to first end  20  of jig  10  spaced longitudinally apart from a second end  84 . First end  82  may be oriented towards first end  20  of jig  10  while second end  84  may be oriented towards second end  22  of jig  10 . Second end  84  may define a planar surface (along with clearance block  108 ) that may abut an end of a piece of wood when jig  10  is in operation, as discussed below. First end plate  16  may also have a first side  86  generally oriented towards first side  24  of jig  10  spaced horizontally or transversely apart from second side  88  which may be generally oriented towards second side  26  of jig  10 . First end plate  16  may have a top surface  90  which may be oriented towards top side  28  of jig  10  and spaced vertically apart from a bottom surface  92  which may be oriented towards bottom side  30  of jig  10 . First end plate  16  may be generally rectangular in shape with a pair of symmetrical and opposing mounting regions  94  on the first and second sides  86 ,  88  thereof. Mounting regions  94  may be projections extending transversely from each side  86 ,  88  of first end plate  16  for operational engagement with a first clamping pad  96  and a second clamping pad  98 . 
     First end plate  16  may include a first stop member  100  having a stop member pointer  101  formed thereon. First stop member  100  may be disposed within a stop member adjustment slot  102  defined through first end plate  16  and held in place therein with stop member thumb screw  104 . First stop member  100  may have an elongated lower portion  106  configured to sit within stop member adjustment slot  102  to allow adjustment of stop member  100  longitudinally along the length of stop member adjustment slot  102 , as discussed below. First member  100  may extend over and above first and second rails  12 ,  14  such that first stop member  100  may lay adjacent to and in contact with top surfaces  40 ,  72  of first and second rails  12 ,  14 . Stop member pointer  101  may be a projection extending from stop member  100  to provide a visual reference on ruler  52 , as discussed below. Stop member adjustment slot  1302  may extend longitudinally between first and second ends  82 ,  84  of first end plate  16 . 
     First end plate  16  may further include a first clearance block  108  which may be removeably connected to a first clearance block mount  110 . First clearance block  108  may be a small block of wood or other suitable material that may abut the edge of a board in which a dado is to be cut to prevent splintering and/or tear-out of the wood, as discussed below. First clearance block  108  may have a clearance hole  109  defined therein that may extend a partial distance through first clearance block  108 . 
     The bottom surface  92  of first end plate  16  may include a first clearance block opening  112  which may be a recess or other feature defined within the bottom surface  92  of first end plate  16  to prevent damage to first end plate  16  by a router bit  170  that is set too deep when jig  10  is being used, as discussed below. According to one aspect, first clearance block  108  may be operationally connected to first clearance block mount  110  via screws (as shown), bolts, clips, adhesive, or any other suitable attachment means. 
     First end plate  16  may include a first horizontal adjustment slot  114  defined therethrough to accept the horizontal adjustment knob  80  to further facilitate horizontal or transverse adjustments of second rail  14  relative to first rail  12  as discussed further in the operation section below. 
     First end plate  16  may be generally located at first end  20  of jig  10  and may be operationally connected to first and second rails  12 ,  14  and first and second clamping pads  96 ,  98  through various connection means, including screws, bolts, rivets, clips, adhesives, or the like. Where the relationship between first end plate  16  and other components includes a movable connection (e.g. second rail  14  or first stop member  100 ), the connections may be accomplished through horizontal adjustment knob  80  and/or stop member  100  and stop member thumbscrew  104 . 
     First rail  12  may be fixed relative to first end plate  16  and may be connected thereto with bottom surface  42  of first rail  12  adjacent to, and in contact with, top surface  90  of first end plate  16 . First rail  12  may be fixedly attached thereto using screws, bolts, clips, adhesives, or the like. It is contemplated that first end  32  of first rail  12  will be aligned and flush with first end  82  of first end plate  16  and fixed relative thereto. This fixed attachment may align first rail  12  orthogonal to first end plate  16  and may serve as a 90° fence to further facilitate the operation of jig  10 , as discussed further below. 
     Second rail  14  may be likewise connected to first end plate  16  at the first ends  32 ,  82 , respectively, thereof; however, second rail  14  may be moveable relative to first end plate  16  via first horizontal adjustment slot  114  and horizontal adjustment knob  80 . Specifically, the first end  64  of second rail  14  may be flush with first end  82  of first end plate  16  but may move in a transverse direction relative thereto to accommodate wood stock of varying widths, as discussed further herein. 
     First clamping pad  96  and second clamping pad  98  may be fixedly connected to mounting regions  94  of first end plate  16  via bolts, screws, clips, adhesive, or other suitable connection methods. First and second clamping pads  96 ,  98  may be utilized to temporarily fix first end  20  of jig  10  to a workpiece to prevent movement thereof while jig  10  is being used as discussed below. First and second clamping pads  96 ,  98  may be formed of any suitable solid material, such as stainless steel, aluminum, anodized aluminum, phenolic, or the like. 
     Second end plate  18  may be substantially similar to first end plate  16  in shape and configuration with the exception that it may be oriented such that it is the mirror image of first end plate  16 . Specifically, second end plate  18  may have a first end  116  spaced longitudinally apart from the second end  118 . First end  116  may be the end oriented towards first end  20  of jig  10  and may define a planar surface (along with second clearance block  144 ) which may abut a second end of a piece of wood when jig  10  is in use, as discussed below. Second end  118  of second end plate  18  may be oriented towards second end  22  of jig  10 . Second end plate  18  may also include a first side  120  generally oriented towards first side  24  of jig  10  spaced transversely apart from a second side  122  which may be generally oriented towards second side  26  of jig  10 . Second end plate  18  may have a top surface  124  spaced vertically apart from a bottom surface  126  with top surface oriented towards top side  28  of jig  10  and bottom surface  126  oriented towards bottom side  30  of jig  10 . 
     Second end plate  18  may have mounting portions  128  which may be substantially similar to mounting portions  94  of first end plate  16 . Specifically, mounting portions  128  may extend transversely outward from first and second sides  120 ,  122  and may provide mounting points for third clamping pad  130  and fourth clamping pad  132 . As with first and second clamping pads  96 ,  98 , third and fourth clamping pads  130 ,  132  may be any suitable material that may be mounted to or otherwise attached to mounting region  128  via screws, bolts, rivets, adhesives, clamps, or any other suitable attachment method. 
     First through fourth clamping pads  96 ,  98 ,  130 ,  132  may be mounted to mounting regions  94 ,  128  in such a configuration to provide a flush transition and surface across the underside of clamping pads  96 ,  98 ,  130 ,  132  with the bottom surfaces  42 ,  74  of first and second rails  12 ,  14  to maintain a flat and uniform surface that may abut a face of a workpiece. 
     The mounting region  128  disposed on first side  120  of second end plate  18  may further support a pivoting reference marker  134 . Pivoting reference marker  134  may be pivotably mounted to mounting region  128  on first side  120  of second end plate  18  and may pivot between a first position (as best illustrated and seen in  FIG. 1B ) wherein the marker is adjacent to first rail  12  and a second position (as best seen in  FIG. 17 ) wherein the marker extends over and across top surface  40  of rail  12 . Pivoting reference member  134  may be vertically offset to provide clearance over the side of first rail  12  and to facilitate the rotation across the top surface  40  thereof. Pivoting reference marker  134  may serve a substantially similar function to reference line  56  as discussed below; however, pivoting reference marker  134  may be in a fixed mounted position relative to second end plate  18  rather than fixed relative to first rail  12  to maintain the proper alignment of pivoting reference marker  134  with first end  116  of second end plate  18 , as discussed further below. Pivoting reference marker  134  may include a stop arm  135  that may be orthogonal to pivoting reference marker  134  and may interact with outer side  36  of first rail  12  to prevent pivoting reference marker  134  from over-rotation. 
     Second end plate  18  may further include a second stop member  136  having a stop member pointer  137 . Second stop member  136  may be substantially similar to first stop member  100  in that it may be a mirror image thereof. Accordingly, second stop member  136  may also have an elongated lower portion  142  mounted within a stop member adjustment slot  138  defined in second end plate  18 . Second stop member  136  may further include a stop member thumb screw  140  to secure second stop member  136  in position. Second stop member  136  may likewise extend over and above first and second rails  12 ,  14  such that second stop member  136  may lay adjacent to and in contact with top surfaces  40 ,  72  of first and second rails  12 ,  14 . Stop member pointer  137  may be a projection extending from stop member  136  to provide a visual reference on ruler  52 , as discussed below. Stop member adjustment slot  138  may extend longitudinally between first and second ends  116 ,  118  of second end plate  18 . 
     Second end plate  18  may also include a second clearance block  144  which may be removeably connected to a second clearance block mount  146 . Second clearance block  144 , similar to first clearance block  108 , may be a small block of wood or other suitable material that may abut the edge of a board in which a dado is to be cut to prevent splintering and/or tear-out of the wood, as discussed below. Second clearance block  144  may have a clearance hole  145  defined therein that may extend a partial distance through second clearance block  144 . According to one aspect, first and second clearance blocks  108 ,  144  may be interchangeable. 
     Bottom surface  126  of second end plate  18  may further have a second clearance block opening  148  defined therein to prevent damage to second end plate  18  by a router bit  170  that is set too deep when jig  10  is being used, as discussed below. As with first clearance block  108 , second clearance block  144  may be removeably mounted to second clearance block mount  146  via screws (as shown), pins, bolts, adhesives, or the like. 
     Second end plate  18  may further include a second horizontal adjustment slot  150  defined therethrough through which two-way adjustment knob  78  may be secured, as discussed below. 
     Second end plate  18  may be generally positioned towards second end  22  of jig  10 . However, it may be longitudinally moveable between a position where second end  118  of second end plate  18  is substantially flush with second end  34  of first rail  12  and second end  66  of second rail  14 , and a plurality of positions along first and second longitudinal adjustment slots  44 ,  76 . The movements and adjustments of second end plate  18  and various other components are discussed further below with regards to the operation and use of jig  10 . Second end plate  18 , as with first end plate  16 , may be positioned such that top surface  124  of second end plate  18  may be adjacent to and in contact with bottom surfaces  42 ,  74  of first and second rails  12 ,  14 , respectively, and may be operationally connected thereto by longitudinal adjustment knob  46 , two-way knob  78 , and/or stop member  136  and stop member thumbscrew  140 . 
     First and second end plates  16 ,  18  may be formed from any suitable rigid material including, but not limited to, metal or synthetic material including, but not limited to, steel, stainless steel, aluminum, phenolic, or the like. According to one aspect, first and second end plates  16 ,  18  may be formed from anodized aluminum. As with first and second rails  12 ,  14 , first and second end plates  16 ,  18  may be formed through any suitable manufacturing method including, but not limited to, extrusion, molding, and/or milling methods. 
     With reference to  FIG. 3 , the top plan view of jig  10  is shown with reference numerals removed for clarity apart from the numerals indicating first end  20 , second end  22 , first side  24 , and second side  28  for orientation purposes. As depicted therein, jig  10  may have an overall length L 1  corresponding to the longitudinal distance between first end  20  and second end  22 . More particularly, length L 1  represents the total longitudinal length of first and second rails  12 ,  14  and may define the maximum longitudinal length of jig  10 . Length L 2  represents the distance between second end  84  of first end plate  16  and first end  116  of second end plate  18 . This distance L 2  may vary as second end plate  18  is adjusted along first and second longitudinal adjustment slots  44 ,  76  as discussed further herein. Specifically, second end plate  18  may be adjusted longitudinally relative to first and second rails  12 ,  14  such that distance L 2  may be at a maximum as depicted in  FIG. 3  when second end  118  of second end plate  18  is even with the second ends  34  and  66  of first and second rails  12 ,  14 . Length L 2  may be at a minimum when second end plate  18  is adjusted along the longitudinal adjustment slots  44 ,  76  to a point that the alignment screw  47  and the two-way adjustment knob  78  contact the opposite ends of the longitudinal adjustment slots  44 ,  76  closest to first end  20  of jig  10 , respectively. 
     As seen in the figures, first longitudinal adjustment slot  44  may be longer than second longitudinal adjustment slot  76  by a distance equal to the distance between alignment screw  47  and longitudinal adjustment knob  46 . The extra length of first longitudinal adjustment slot  44  may account for this distance to keep second end plate  18  square to the workpiece as discussed further below. According to one aspect, length L 2  may then define the minimum and maximum lengths of dadoes that may be cut utilizing jig  10 . As longitudinal adjustment slots  44 ,  76  have no predetermined stops, length L 2  may occupy any specific distance between a that minimum and maximum range. According to one aspect, the minimum length of L 2  may be approximately five inches which the maximum may be approximate 24½ inches and length L 2  may be therefore any specific length within that range. According to another aspect, jig  10  may be constructed and sized to allow for range in which length L 2  may be larger or smaller as desired. 
     With continued reference to  FIG. 3 , the overall width of jig  10  may be indicated as W 1  and may exclude first through fourth clamping pads,  96 ,  98 ,  130 ,  132  and mounting regions  94 ,  128 . Thus width W 1  may represent the transverse distance between first and second sides  86 ,  88  of first end plate  16  and first and second sides  120 ,  122  of second end plate  18 . With first rail  12  fixedly attached to first end plate  16 , the junction therebetween may remain constant allowing for second rail  14  to be transversely or horizontally adjusted to account for wood stock of varying widths to be utilized to produce dadoes of varying widths equal to the width of the wood stock, as discussed below. The width range of the dado is therefore represented as width W 2  and may be the distance between edge guides  58  disposed on the bottom surfaces  42 ,  74  of first and second rails  12 ,  14 . Specifically, second rail  14  may move horizontally relative to first rail  12  and first and second end plates  16 ,  18  via operation of two-way knob  78  and horizontal adjustment knob  80  in first and second horizontal adjustment slots  114 ,  150 . As second rail  14  moves, the edge guide  58  disposed thereon may also move horizontally relative to the edge guide  58  disposed on first rail  12 . Width W 2  therefore may be any width between a maximum width wherein two-way knob  78  and horizontal adjustment knob  80  contact the ends of horizontal adjustment slots  114 ,  150  closest to second side  26  of jig  10  and a minimum width wherein two-way knob  78  and horizontal adjustment knob  80  contact ends of horizontal adjustment slots  114 ,  150  closest to first side  24  of jig  10 . At the maximum width, outer side  68  of second rail  14  is aligned and flush with second sides  88 ,  122  of first and second end plates  16 ,  18 , respectively. According to one aspect, the minimum width W 2  is be equal to or greater than the diameter of a router bit  170  (once edge guides  58  have been trimmed appropriately, discussed below) as the router bit  170  must able to extend through jig  10  in order to cut an associated dado in workpiece as discussed below. According to one aspect, this minimum width W 2  may be ⅜ inch while the maximum width may be 1½ inches. According to another aspect, jig  10  may be configured and constructed such that the range in which width W 2  may fall may be larger or smaller than the range provided herein. 
     With reference now to  FIGS. 4-5 , a guide bushing  152  may be utilized with a router  168  (best seen in  FIG. 5 ) to facilitate proper positioning router  168  within jig  10  while cutting a dado. Guide bushing  152  may be a two-piece bushing having a bushing adaptor  154  and a bushing collar  156 . Bushing adaptor  154  may include an adaptor ring  155  which extends outwardly beyond external threads  162  thereon to create a lip  157 . Adaptor ring  155  may have a diameter equal to the outer diameter of bushing collar  156 . Bushing adaptor  154  may include a spacer ring  158  having an end surface  159  opposite the joint between the spacer ring  158  and the adapter ring  155 . End surface  159  may have an inner edge  160  that may be adjacent to router bit  170  when installed on a router  168 . Bushing adaptor  154  may have a through opening  160  that extends through the interior of spacer ring  158  and into the interior  166  of bushing adaptor  154 . This through opening may allow a router bit  170  to extend therethrough when guide bushing  152  is installed on the router  168 . Bushing adaptor  154  may include external threads surrounding the interior  166  while bushing collar  156  may include internal threads  164  and may be sized so that bushing collar  156  may fit over the threaded portion  162  of bushing adaptor  154 . Guide bushing  152  may be installed on a router  168  with bushing adaptor  154  on an outside or an outer portion of a router fence  172  while bushing collar  152  may be threadedly engaged with external threads  162  of bushing adaptor  154  to secure guide bushing  152  in place on opposite sides of router fence  172  as seen in  FIG. 5 . Router bit  170  may be inserted through the through opening  160  in bushing adaptor  154  for operational engagement with the router  168 . 
     Guide bushing  152 , or more specifically, space ring  158 , may ride along the inner sides  38 ,  70  of first and second rails  12 ,  14  when cutting a dado and may also be utilized in preparing the edge guides  58  for use with dado jig  10 , as discussed below. 
     As further seen in  FIG. 5 , offset notch  53  of ruler  52  may be sized to be equal to the vertical thickness of rails  12 ,  14  with edge guides  58  installed to properly set the depth of the router bit  170 . Therefore, the offset notch  53  defines the beginning of the offset scale  54  starting at zero and extends up from the top of offset notch  53  so that the router depth may be appropriately set accounting for the thickness of jig  10 . According to the example seen in  FIG. 5 , a router depth of ¼ inch is shown wherein the tip of the router bit  170  terminates ¼ inch above the offset notch  53  on offset scale  54 . Scale  55  of ruler  52  is discussed further below relative to the operation of jig  10  in cutting blind dadoes  206 . 
     Having thus described the elements and components of dado jig  10 , the operation and methods of use therefore will now be discussed. 
     With reference to  FIGS. 5-15 , the operation of dado jig  10  is depicted and discussed herein with reference to cutting an open dado  204  as seen in  FIG. 15 . 
     Prior to operating jig  10 , two set-up steps must first be undertaken. First, as depicted in  FIG. 5 , a router bit  170  needs to be selected and set to the desired depth utilizing ruler  52 . Router bit  170  may be any desired router bit; however, as depicted and discussed herein, a straight bit is used. The specific depth of the cut may be determined on a desired basis dictated by the user&#39;s preference and the particular workpiece being created. To set the depth for router bit  170 , the ruler  52  may be placed with offset notch  53  rising up and over spacer ring  158  and with offset scale  54  adjacent to router bit  170 . The router bit  170  may then be adjusted using offset scale  54  to the desired depth. As shown in  FIG. 5  and for purposes of this example, the depth may be set to ¼ inch. The offset notch  53  and offset scale  54  may account for the vertical thickness of jig  10  to allow for the depth of router bit  170  to be set from the surface of the workpiece rather than from the top surfaces  40 ,  72  of first and second rails  12 ,  14 . 
     The second preoperative step is to prep the edge guides  58  to accept the specific router bit  170  chosen for use. Generally speaking, this step need only be performed once per router bit (and for any router bit of the same diameter/size) in that edge guides  58  may be trimmed by this step to allow appropriate spacing for the router bit  170  to be inserted therebetween. Accordingly, to prep the edge guides  58  once the router bit  170  is installed in router  168 , jig  10  may be placed on a piece of scrap or in another suitable position to allow edge guides  58  to be cut without damaging or otherwise cutting the actual workpiece during the prepping step. Once jig  10  is placed, it may be clamped in position utilizing clamps  188  to hold one or more of the first, second, third, and/or fourth clamping pads  96 ,  98 ,  130 , and/or  132  against the piece of scrap. The two-way adjustment knob  78  and horizontal adjustment knob  80  may be loosened allowing second rail  14  to move horizontally with respect to first and second end plates  16 ,  18 . The router  168  may be placed in position atop first and second rails  12 ,  14  and first and second rails  12 ,  14  may be closed against spacer rim  158  of guide bushing  152 . This may provide the proper spacing between the inner side  38  of first rail  12  and the inner side  70  of second rail  14 . A separate spacer (not shown) may be provided to be placed between first and second rails  12 ,  14  at the opposite end of jig  10  to insure proper spacing along the entire longitudinal length of first and second rails  12 ,  14 . Once first and second rails  12 ,  14  are positioned against spacer ring  158 , the two-way adjustment knob  78  and horizontal adjustment knob  80  may be tightened and the additional spacer (if used) may be removed. At this point, the router  168  may be powered on and the router bit  170  may be moved into the edge guides  58  to trim them to the appropriate width to provide proper clearance for router bit  170  for further use in cutting dadoes as described below. 
     Once the router bit  170  depth is set and the edge guides  58  are prepped for the specific sized router bit  170  being used, jig  10  is now ready for use in cutting exact width dadoes. Accordingly, first described herein is the operation of jig  10  for cutting an open dado  204  as depicted in  FIG. 15 . Once the operation of jig  10  is discussed fully with regards to an open dado  204 , additional operation for cutting blind dadoes  206  ( FIG. 18 ) will be described. 
     The processes described herein will be discussed utilizing a first board  174  and a second board  190  to cut a single dado. However, it will be understood that a plurality of boards may be used to cut multiple dadoes depending upon the desired end product. The operation of jig  10  would be the same for each dado recognizing that the jig  10  would be moved to the appropriate and desired position for each dado to be cut. 
     With reference now to  FIG. 6 , jig  10  may be placed in an appropriate position on a first board  174  having a first end  176  spaced longitudinally apart from a second end  178 , a first side  180  spaced transversely apart from a second side  182 , and a top face  184  spaced vertically apart from a bottom face  186  and defining the thickness of first board  174  therebetween. The jig  10  may be placed so that the longitudinal length L 1  of jig  10  may extend in the longitudinal direction across first board  174 . First end plate  16 , or more specifically, the planar surface defined by second end  84  of first end plate  16  may be abutted against first end  176  of first board  174 . The fixed corner formed between first end plate  18  and first rail  12  may create a 90° fence which may keep the jig  10  perpendicular to first edge  176  without the need for a separate square to set up jig  10  in the appropriate position. First end  176  may then be clamped in place with second end  84  of first end plate  16  abutted against first end  176  of first board  174  via first and second clamping pads  96 ,  98  which may extend transversely across the top face  184  of first board  174  and may be clamped thereto utilizing standard woodworking clamps  188  or any other suitable clamping device. 
     Next, the longitudinal adjustment knob  46  and two-way adjustment knob  78  may be loosened to allow movement of second end plate  18  relative to first end plate  16  and first and second rails  12 ,  14  to accommodate the longitudinal width of first board  174 . If movement of second end plate  18  and/or second rail  14  is impeded by first and/or second stop members  100 ,  136 , the first stop member thumb screw  104  and/or second stop member thumb screw  140  may be loosened to further allow unimpeded movement of second end plate  18  and/or second rail  14 . Second end plate  18  may be moved longitudinally towards first end plate  16  to abut the planar surface defined by first end  116  of second end plate  18  against second end  178  of first board  174 . Once second end plate  18  is in position with first end  116  abutting the second end  178  of first board  174 , longitudinal adjustment knob  46  may be tightened to secure second end plate  18  in position before clamping second end plate  18  and jig  10  against the first board  174  utilizing third and fourth clamping pads  130 ,  132  and clamps  188  or other suitable attachment device. Jig  10  is now properly positioned with the longitudinal adjustment made to accommodate the longitudinal width of first board  174 . In this position, the planar surfaces defined by second end  84  of first end plate  16  and first end  116  of second end plate  18  are abutted against the first and second ends  176 ,  178  of first board  174 . In this position, the first and second clearance blocks  108 ,  144  are likewise abutted against the first and second ends  176 ,  178  of first board  174  and aligned with where the open dado  204  will be cut. 
     Once the longitudinal length of jig  10  has been adjusted and jig  10  has been clamped to first board  174  via first, second, third, and/or fourth clamping pads  96 ,  98 ,  130 , and/or  132  and clamps  188 , a second board  190  may be used to set the horizontal width of jig  10 . As with first board  174 , second board  190  may have a first end  192  spaced longitudinally apart from a second end  194 , a first side  196  spaced transversely apart from a second side  198 , and a top face  200  spaced vertically apart from a bottom face  202  and defining the thickness of second board  190  therebetween. 
     As seen best in  FIG. 7 , second board  190  may inserted between first and second rails  12 ,  14 , or more specifically between edge guides  58  of first and second rails  12 ,  14 , and oriented perpendicularly to first board  174  such that one of the first or second sides  196 ,  198  of second board  190  may be in contact with the top face  184  of first board  174 . As the open dado  204  is to be cut into the top face  184  of first board  174  along the longitudinal length between first end  176  and second end  178  thereof, second board  190  should be oriented with first end  192  of second board  190  towards first end  176  of first board  174  and second end  194  of second board  190  towards second end  178  of first board  174 . This positional relationship between first board  174  and second board  190  allows jig  10  to be positioned to properly cut the open dado  204 . 
     Once second board  190  is placed between edge guides  58  of first and second rails  12 ,  14 , second rail  14  may be moved transversely or horizontally in the direction of the arrows indicated in  FIG. 7  to tightly clamp edge guides  58  against the top and bottom faces  200 ,  202  of second board  190 . Now that second board  190  is properly positioned with edge guides  58  tightly held against top and bottom faces  200 ,  202  thereof, horizontal adjustment knob  80  and two-way adjustment knob  78  may be tightened to secure second rail  14  in position and second board  190  may be removed from between first and second rails  12 ,  14  of jig  10 . 
     With reference to  FIG. 8 , with second board  190  removed from between edge guides  58  of first and second rails  12 ,  14 , the area to be cut that will become the open dado  204  can be seen through jig  10  and is indicated in  FIG. 8  with diagonal crosshatching between the edge guides  58 . At this point, once second board  190  has been removed from between the first and second rails  12 ,  14 , stop members  100 ,  136  may be moved to their farthest longitudinal positions towards first and second ends  20 ,  22  of jig  10  to keep stop members  100 ,  136  from interfering with operation of the router  168  when cutting open dadoes  204 . Stop members  100 ,  136  may be moved by first loosening the stop member thumb screws  104 ,  140  and sliding the lower portions  106 ,  142  within the stop member adjustment slots  102 ,  138  to move stop members  100 ,  136  to their desired positions. Once in the desired positions, thumb screws  104 ,  140  may be tightened to secure stop members  100 ,  136  in place. Movement of stop members  100 ,  136  is best seen and indicated by the arrows in  FIG. 8 . 
     With reference to  FIGS. 9-14 , the actual cutting of open dado  204  is depicted and will now be discussed. As shown in these figures for purposes of clarity, particularly in  FIGS. 9, 10, and 12-14  (and in  FIGS. 16-17 , discussed below), the router  168  and router fence  172  are indicated therein as a large circle made of a dot-dot-dash line with router bit  170  drawn in the center of the circle as a smaller circle rendered with a solid line. Guide bushing  152 , and more particularly spacer ring  158  thereof, is likewise depicted towards the center of the router  168  circle as a slightly larger circle than router bit  170 , but rendered in a dot-dot-dash line format. These components have been depicted as such to clearly show how the open dado  204  is being cut without obstruction. 
     Accordingly, with reference to  FIGS. 9-10 , the router  168  may be placed atop the top surfaces  72 ,  90  of first and second rails  12 ,  14  with router bit  170  inserted into clearance hole  145  of second clearance block  144 . Although depicted being cut from second end  22  towards first end  20  and therefore starting in clearance hole  145  of second clearance block  144 , it will be understood that router  168  may be initially placed at first end  20  of jig  10  with router bit  170  inserted into clearance hole  109  of first clearance block  108  and open dado  204  may be cut initially from first end  20  towards second end  22  of jig  10  without discrimination. As further seen in  FIG. 9 , the router  168  may be placed slightly off center so that spacer ring  158  may contact the inner side  38  of first rail  12  while router bit  170  may contact the guide edge  58  of first rail  12 . Router  168  may be then powered on and moved along the inner side  38  of first rail  12  with router bit  170  riding along the edge guide  58  of first rail  12 . Router may be moved towards first end  20  beginning the cut of open dado  204 . Clearance block  144  is abutted directly against second end  178  of first board  174  to prevent splintering and/or tear-out as router bit  170  enters into the top surface  184  of first board  174  from second end  178 . The area being cut and removed from top surface  184  of first board  174  is indicated by stippling showing the contrast between the uncut regions and cut regions in  FIG. 10  (and  FIGS. 12-14 ). 
     With reference to  FIG. 11 , a cross-section taken along line  11 - 11  from  FIG. 10  is shown with router  168  in operation. The partial cross-section view in  FIG. 11  is provided to show the relationship between router bit  170  and spacer ring  158  with edge guide  58  of first rail  12  and inner side  38  or first rail  12 , respectively. Further, the partial cross-section of  FIG. 11  clearly shows space between edge guide  58  and router bit  170  and between inner side  70  of second rail  14  and spacer ring  158 . This is intentional as router  168  is contemplated to be moved up one rail  12  or  14  of jig  10  to cut open dado  204  and then moved across and down the opposite rail  12  or  14  of jig  10  to finish cutting open dado  204  in two passes. This insures a tight relationship and alignment with inner sides  38 ,  70  of first and second rails  12 ,  14  and edge guides  58  to provide the exact width dado to match the thickness of second board  190 . 
     With reference to  FIGS. 12-14 , router  168  may complete its first pass through top surface  184  of first board  174  reaching first clearance block  108  as router bit  170  enters clearance hole  109 . Router  168  may be moved transversely from a position wherein spacer ring  158  is in contact with the inner side  38  of first rail  12  to a position wherein spacer ring  158  in now in contact with the inner side  70  of second rail  14 . Similarly, router bit  170  may move from edge guide  58  on first rail  12  to edge guide  58  on second rail  14 . Router  168  may then be moved in the opposite direction from first end  20  towards second end  22  of jig  10  to begin cutting the second side of open dado  204 , as best seen in  FIG. 13 . 
     As router  168  is moved through the top surface  184  of first board  174  and into second clearance block  144  and router bit  170  returns into clearance hole  145 , the open dado  204  cut is complete and router  168  may be powered off and removed from jig  10 . The presence of clearance blocks  108 ,  144  held tightly against first and second ends  176 ,  178  of first board  174  may prevent splintering and tear-out of first board  174  and may further facilitate a clean and fine finish to open dado  204 , which is best seen in  FIG. 15 . With open dado  204  now appropriately cut, jig  10  may be removed from first board  174 . 
     If additional open dadoes  204  are desired to be cut within first board  174 , jig  10  may be removed from the position where the first dado  204  was cut and replaced in a second position to cut an additional dado  204  according to the same methods. If the dadoes  204 , or more particularly the additional boards, have the exact same thickness as second board  190 , an abbreviated method may be followed wherein additional horizontal width adjustments of jig  10  may be unnecessary as jig  10  may already be set for boards of exact or similar thickness. Accordingly, where second board  190  is cut from the same stock piece as additional boards, jig  10  may be set up once and rapidly moved between positions to cut multiple dadoes  204  without adjusting the horizontal width W 2  between edge guides  58  and only minimally adjusting the longitudinal length L 2  to allow movement across top surface  184  of first board  174  before replacing jig  10  in the new location. Alternatively, if no more open dadoes  204  are desired, jig  10  may be unclamped and removed from first board  174  and second board  190  may be appropriately inserted and/or secured within the open dado  204  according to known woodworking methods. 
     With reference now to  FIGS. 16-18 , a method for cutting blind dadoes  206  (best seen in  FIG. 18 ) will now be discussed. A blind dado  206  is one where the cuts into first board  174  are not seen when viewed from one or both of first and/or second ends  176 ,  178 . Specifically, the blind dado  206  has terminal ends  208  that do not reach the first and second ends  176 ,  178  of first board  174 . Jig  10  may be utilized to cut blind dadoes  206  using a very similar or nearly exact method as used for cutting open dadoes  204  discussed above; however, cutting blind dadoes  206  involves the utilization of first and second stop members  100 ,  136 , as well as ruler  52 . 
     To properly utilize jig  10  to cut blind dadoes  206 , two pieces of information must be known. First, the operator must know the distance from the router bit  170  to the outer edge of the router fence  172 . This distance is not standard as different brands and types of routers  168  may have different size of fences  172 . This distance may alternatively be measured or indicated as the distance between the inner edge  161  of the end surface  159  of spacer ring  158  to the router fence  172 . This distance is best shown in  FIG. 16  as distance D 1 . 
     The second piece of information needed to properly set up jig  10  for cutting blind dadoes  206  is the desired distance between the ends  176  and/or  178  of first board  174  and the terminal ends  208  of the blind dado  206 . This distance is indicated as distance D 2  as best seen in  FIGS. 16 and 18 . While it is discussed and contemplated that distance D 2  will be the same or identical between first and second ends  176 ,  178  of first board  174 , depending upon the desired result, jig  10  may be set up to allow different distances between terminal ends  208  of blind dadoes  206 . For example, where a workpiece might be made having a backing thereon, an open dado  204  may be cut at one end, e.g. second end  178 , of first board  174  with a blind dado  206  cut at first end  176 . In this example, the open dado  204  will be hidden from view by the backing while the blind dado  206  will be presented to the front view of the workpiece. It will therefore be understood that any combination of open and blind dadoes  204 ,  206  may easily and quickly cut utilizing jig  10  by simple adjustments or adaptations of the methods provided herein. 
     To properly set jig  10  for cutting blind dadoes  206  and armed with both the distance D 1  between the router bit  170  and the router fence  172  and distance D 2  between the desired terminal end  208  and the ends  176 , and/or  178  of first board  174 , jig  10  may be set to stop the router  168  at the desired position to cut the blind dado  206 . Specifically, with reference to  FIG. 16 , first end  176  may be adjusted by first aligning ruler  52  such that the zero measurement of scale  55  marking is aligned with the reference line  56  on top surface  40  of first rail  12 . 
     Next, the stop member thumb screw  104  for first stop member  100  may be loosened and first stop member  100  may be moved to the desired position by aligning stop member pointer  101  with the appropriate measurement increment on scale  55  of ruler  52 . For example, where distance D 1  is equal to 2½ inches and the desired distance D 2  between terminal end  208  and first end  176  of first board  174  is ½ inch, stop member  100  may be placed such that stop member pointer  101  is aligned with the 2-inch mark on scale  55  of ruler  52 , as depicted in  FIG. 16 . This position will cause router fence  172  to impact stop member  100  with the router bit  170  stopping ½ inch short of the first end  176  of first board  174 . 
     With reference to  FIG. 17 , setting the second end  22  of jig  10  for a similar stop may be accomplished using scale  55  of ruler  52  and pivoting reference member  134 . First, ruler  52  may be slid along ruler channel  48  to the second end  22  of jig  10 . Next, the pivoting reference marker  134  may be pivoted from the first position to the second position wherein it extends over and across top surface  40  of first rail  12 . As seen in  FIG. 17 , pivoting reference marker  134  extends over the space occupied by ruler channel  48  and ultimately over ruler  52  to provide a reference point aligned with the second end  178  of first board  174 . When ruler  52  is merely slid to second end  22  of jig  10 , the measurement marking positions on scale  55  of ruler  52  may be reversed. For example, again using D 1  as 2½ inches and D 2  as ½ inch, where reference line  56  was aligned with the zero point on scale  55  and stop member pointer  101  was aligned at 2 inches on scale  55 , the opposite may be utilized at second end  22  such that pivoting reference marker  134  may be aligned at 2 inches and stop member pointer  137  may be aligned at the zero inch mark on scale  55  of ruler  52 . This reversed measurement will result in router fence  172  contacting second stop member  136  with router bit  170  stopping ½ inch short of reaching second end  178  of first board  174 . 
     Alternatively, ruler  52  may be removed from ruler channel  48  by loosening ruler thumb screw  50  and sliding ruler  52  out of the end of ruler channel  48  at first end  32  of first rail  12 , rotating ruler 180° to place scale  55  in the opposite orientation and reinserting ruler  52  into ruler channel  48  at first end  32  of first rail  12  before sliding ruler  52  to second end  22  of jig  10 . 
     With the first and second stop members  100 ,  136  in the desired positions, router  168  may again be placed on the top surfaces  40 ,  72  of first and second rails  12 ,  14  and may be plunged into the top face  184  of first board  174 . As router bit  170  is not being moved through the end plane of first and second ends  176 ,  178  of first board  174 , splintering and/or tear-out will be minimal or eliminated, therefore, not requiring the use of clearance blocks  108  and/or  144 . Router  168  may then be moved laterally between first and second ends  20 ,  22  of jig  10  while maintaining contact with the inner side  38  or  70  of first or second rail  12  or  14  by spacer ring  158  and with edge guides  58  of first or second rails  12  or  14  by router bit  170 . 
     As router  168  is moved the length of the jig  10 , router fence  172  will contact the stop member  100  or  136  at the opposite end  20  or  22  of jig  10 , and router  168  will not be able to progress further. Router  168  may then be moved transversely to contact the inner side  38  or  70  of the opposite rail  12 ,  14  with spacer ring  158  and the opposite edge guard  58  with router bit  170 . Router  168  may then be moved in the opposite direction between first and second ends  20  and  22  of jig  10  until the router fence  172  contacts the opposite stop member  100  or  136 . At this point, the blind dado  206  is complete and router  168  may be switched off and removed from jig  10 . 
     As with open dadoes  204 , if additional blind dadoes  206  are desired, jig  10  may be moved to the new position to cut additional blind dadoes  206 . Alternatively, if no more blind dadoes  206  are desired, jig  10  may be unclamped and removed from first board  174  and second board  190  may be appropriately inserted and/or secured within the blind dado  206  according to known woodworking methods. 
     Various inventive concepts may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. 
     While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure. 
     The articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” The phrase “and/or,” as used herein in the specification and in the claims (if at all), should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law. 
     As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc. 
     When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature. 
     Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “above”, “behind”, “in front of”, and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal”, “lateral”, “transverse”, “longitudinal”, and the like are used herein for the purpose of explanation only unless specifically indicated otherwise. 
     Although the terms “first” and “second” may be used herein to describe various features/elements, these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed herein could be termed a second feature/element, and similarly, a second feature/element discussed herein could be termed a first feature/element without departing from the teachings of the present invention. 
     An embodiment is an implementation or example of the present disclosure. Reference in the specification to “an embodiment,” “one embodiment,” “some embodiments,” “one particular embodiment,” or “other embodiments,” or the like, means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the invention. The various appearances “an embodiment,” “one embodiment,” “some embodiments,” “one particular embodiment,” or “other embodiments,” or the like, are not necessarily all referring to the same embodiments. 
     If this specification states a component, feature, structure, or characteristic “may”, “might”, or “could” be included, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to “a” or “an” element, that does not mean there is only one of the element. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element. 
     As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. 
     Additionally, any method of performing the present disclosure may occur in a sequence different than those described herein. Accordingly, no sequence of the method should be read as a limitation unless explicitly stated. It is recognizable that performing some of the steps of the method in a different order could achieve a similar result. 
     In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures. 
     In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
     Moreover, the description and illustration of various embodiments of the disclosure are examples and the disclosure is not limited to the exact details shown or described.