Asymmetric Through Dovetails
Asymmetric or not equally spaced dovetails are quick to cut on the Router Boss and look good too. Use them for speed or to avoid flaws or knots in the wood. Arrange the spacing so that you can have a deep lid without cutting through a pin etc. Now that I have the Router Boss all set up on it's new bench mount I have described a method of making them. The description may seem long but in practise they are simple to cut. There is one overriding thing to remember and that is the opposing sides are mirror images of each other. This method is far from the only way but if you follow the side orientation description here then you can't go wrong. I have included three PDF 'crib' sheets for you to download if you want to place them with your manual for reference.
Well here we go: If you are new to the RB and getting to grips with the setting up then good quality pine will be be OK to gain experience with but if you are more confident then contrasting hardwoods look good. Remove the rulers from the box section and replace them with the white 'story board' strips.
Click on the notes below to enlarge them. The excellent artwork for these notes was produced by Dave Richards and remain his copyright. It would be best if follow this link and print out the full PDF for reference.
Thanks Dave , You did a great job!
|For this demonstration I have selected some cheap pine.
Prepare all four sides ensuring they are flat, square and of equal thickness. Set them up on your bench as shown and clearly label each adjoining corner with the same letter on the outside (good ) side and towards the top. The longer boards will be the tail boards and the shorter right and left sides will be the pin boards.
Examine the wood and decide where the tails are going to be. I will only be cutting three sockets on each corner and space them to avoid knots.
|OK; Using my square I have marked the centre lines of the tail sockets on one front tail board. These lines will be transferred onto the white story board strips of the RB in a certain way.|
|Track the slider to centre on the first line. Line up using the laser cross hairs or a centre point in the router. I am using both. The picture is shot from below because the camera refused the focus on the bright laser from above.|
|Transfer all of the three lines onto the LEFT story board cursor positions. Be
consistent on which edge of the cursor that you use. Refer to the
diagram on sheet 2 above.
Note: This my own and not a kit cursor.
|Rotate the board in the clamp so that the inside unmarked face is now out
nearest to you and repeat the marking process onto the RIGHT side story
|Fit a suitable dovetail bit ( with the power to the router off ).
Tip: stuff a rag into the opening when changing bits as a dropped and damaged one can really spoil your day!
|Plunge the router until the bit just touches the tail board which is
clamped below and lock the plunge lever. Now place a pin board under the
depth setting to set the cutting depth.
Increase the cutting depth by about 1mm or 1/16".
This will cause a small protrusion of the finished tails.
Plane off the finished joint and it will look better.
|Cam up both tail boards with the inside faces together and proceed
to cut the sockets using the cut/flip/cut/track method illustrated in
the sheet 3 above.
Line up the cursor to the marks on the left side.
|Here we are one completed tail board. Two exact copies were cut at the same time. Quick and simple!|
|It is now time to cut the pins and I like to build confidence by
marking through the sockets with a very sharp pencil or striking knife onto the matching
pin board end. You could mark each corner and cut to the line which is
very smooth and easy on the RB but it is still possible to get the
mirror joints wrong. So lets continue with this method.
Sheet1 lower drawing.
|Here are the marked out pins. Bear with me and you will see the reason soon!|
|OK We now have to set the wing angles but firstly loosen the binding bolts and then set the angle by inserting the setting pins.|
|I am using an 8 degree dovetail bit so the pins have to match.
The setting pins are in the 8 degree holes. When set
*re-tighten the binding bolts.
*( Lightly or they could break)
|I am using a 5/16" dovetail bit and a 3/8" straight bit from the Craftsman Gallery premium range so if I refer to the instruction manual tables I find that the side scales should be set to 62.|
|Here we are set at 62, on both sides don't forget.
Ensure the rails are level with the edge of the main plate and that the scales are zeroed onto the face of the box section.
If you have a spare board of the correct dimensions you can cut a test pin and try it in the tail boards.
If you don't have a spare board or are using your own metric cutters that do not match the settings chart you must find your own scale settings.
A calculator for a much greater range of cutters is now available here !!
|Using the marked pin board swing the router plate either side to engage with the green wings and test the cutter position. Here the 62 scale setting is exactly spot on.|
|This is wrong and would cut a pin too big. To reduce the cutting width move the guide rails back say half to one scale increment at a time and retest. Move the rails towards you for the opposite effect.|
|Once satisfied with the settings we can start to cut the pins after
setting the cutting depth of course. To ensure the right and left pin
boards are mirror images closely follow the cutting sequence described
in sheet 3 above.
Note: Both the left and right side story boards are used for this.
|Here is a finished pin board.|
|A perfect fit! Not too tight and not too loose. Notice the 1 mm projection which was by design. When planed down the joint will look great.|
|This is a very small box with asymmetric joints. I will fit a top and base and cut the deep lid off between the upper and middle tails.|
|And this is one using maple and mahogany Planed but waiting to be
Dovetails look great in contrasting woods. The next one I will cut with a finer dovetail bit to give that 'hand cut' look.
So there we are not difficult is it? The Router Boss was a pleasure to use and very smooth in action.
A few comments on the RB:
Very smooth in action in all directions.
Clear view and well lit down through the router base.
Rear dust extraction worked much better than expected although all chips were not captured. Probably because I did not fit the front extraction which could have improved collection more!
The cursors made it very simple to repeat the cuts so knocking out a number of similar drawers would be easy.
The gearing of the sliding bar is set just right for easy driving and cutting to the line potentially saving a lot of set up time.
The lack of any 'rattle' or play in the sliding bar is a godsend.
The plunge action is so good I found I did not need the front post and worked very comfortably without it.
The laser beams are a little wide but I did not find any problems setting the the centre line. If anything the brightness could be turned down a bit if possible.
It is not too easy to see the lines of the side scales in the cut-out of the rails. It would be better if the opening windows were set further into the rails or cut away to reveal more of the scales.
Nice to have parts:
Centering bit 18-600 $6.0 Double Bevel Striking Knife 34-330 $9.0 6 inch Sliding Bevel 34-370 $6.0 Go to the next page to see some photos and my impressions. Page 2
All available from www.chipsfly.com.
Download and save or print the full PDF of notes here
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