Chiefwoodworker's Blog

I promised my daughter that upon her graduation from law school I would give her a wall hanging Shaker style clock. She graduated in the spring of 2008. I completed this clock in October of 2009. A little late; but to keep anyone from finding out I printed 2008 on the clock dial. Pretty clever huh?

The clock carcass is cherry and though not visible is constructed with hand cut dovetail joinery. The back of the pendulum compartment is spalted maple which gives this relatively large area some interesting figure for eye appeal. To provide contrast the doors are made of walnut.

In keeping with the Shaker theme the trim is simple bull nose and quarter round. Door pulls are turned "mushrooms" typical of what the Shakers would use.

The clock dial was drawn using Google SketchUp. The four I’s to represent the numeral four is not a mistake. Though four is correctly represented as IV it is traditional in clocks to represent it as IIII.

After drawing the clock dial in SketchUp I applied an antique texture behind the numerals to add a little "age". Next I printed the dial full scale on 13" X 19" premium card stock. To protect the dial I applied seven coats of Spray-On MinWax Satin Polyurethane with the added benefit of still more aging (it dries slightly yellow). Finally the card stock is glued to a plywood backing. – Did he say plywood? Yes, an extremely rare occasion when I use anything but hardwood in my projects.

The mechanical clock movement is a German made Hermle model 241-080. It is an 8-day movement with a gong that strikes once on the half hour and counts out the hours. The serpentine hands are not in keeping with the Shaker style. Mother Ann would definitely not approve, but hey, my daughter likes them. The chains, bob and weights are brass plated. If you look closely at the bob you can tell these pictures were taken in my shop. The bob shows a reflection of me and my 15" planer.

To complete this project I used non-mortising hinges and rare earth magnetic catches. The hinges have an antique brass finish. To keep the clock level in the vertical direction I used two adjusting pins that have sharp points which dig slightly into the wall and can also be adjusted for level in the orthogonal vertical plane. These pins are made especially for this purpose and are a traditional piece of clock hardware. I finished this piece with seven coats of hand rubbed MinWax Wipe-On Polyurethane Satin Finish.

The backs of a custom piece serve a number of functions and they are far from simple pieces of wood. The upper back in this piece provides a mechanism for hanging the clock while it also serves to keep dust out of the clock’s works. The upper back is not, however, visible since it is hidden by the clock dial.

The bottom back is visible, just behind the weights and pendulum that drive the clock. It also serves to keep dust out of the case. However, because the swinging pendulum will draw all eyes to itself and the back, it is important that the back not look like a plain piece of wood, but rather adds to the beauty of the clock. For this clock spalted maple serves that purpose. The random black lines of the early fungus and the tan and greenish color of the wood provides the viewer with an artistic drawing that only nature could render.

Backs almost always require special treatment to allow for seasonal expansion and contraction. In large pieces I often use ship lapped boards that are spaced one from the other to allow for seasonal movement. Theses backs are not wide enough to accommodate this approach. Instead, after calculating the expected movement, I cut the backs narrow by 1/4” and fastened them with slotted open holes, washer and screws. I cut them narrow because expansion season has only barely begun, and at its peak, the backs will expand to close the gap. If this were peak expansion season I would have cut them to fit and let them shrink to their minimum size. The washer and screws hold the back flat but also lets it move under the washer. I am careful not to tighten too much. Notice that I center the backs so that the gap for expansion is equal on each side.

The hardware and glass are on order and as soon as they arrive I will attach them. Then it is a simple matter of applying finish. For this clock I am going to use Min-Wax Wipe-On Poly Satin Finish.

The doors of this clock are made of black walnut (aka American walnut) chosen to provide contrast to the lighter, and more red shade of cherry. Walnut, while an excellent furniture wood, is not one I like working with much. There are very few adverse health effects related to walnut though there have been documented reports of skin irritation, rhinitis and asthma. But the saw dust generated by walnut is very fine and highly noticeable even with the use of dust masks. I find its taste bitter and unpleasant. So, while it is a beautiful furniture wood I tend to use if for contrasting trim and doors and seldom build an entire piece out of it.

Most of the walnut pieces in this clock are short, about 12”. So I have chosen to thickness plane them with my drum sander and avoid the problem of sniping. I load the drum sander with 80 grit paper. After joining and planing three sides with a power jointer followed by a hand jointer and smooth planes, I cut them to near length and thickness them on the drum sander.

After bringing the pieces to within 1/16” of final thickness using 80 grit paper I switch to 220 grit for final thicknessing. I don’t have to run through all the grits in between because I am taking off more with the 220 grit paper than the depth of the groves left by the 80 grit paper. I would not suggest trying this with a random orbital sander though.

The drum sander has many uses not immediately obvious. For example, power planing a tiger or blistered maple board will often leave tear out because of the rapid grain changes. The drum sander is an excellent choice for final thicknessing in this case. Also, the safest way to taper legs is a drum sander. You might first rough cut the taper close to the line with a band saw and follow it up with a drum sander, or skip the drum sander altogether. Either way you avoid the dangerous step of either a table saw or a jointer.

When thicknessing is complete I cut a 3/8” wide by 1/2” deep rabbet in all pieces. Normally I would do this with a set of dado blades. But if I do this on the table saw instead, the off cut pieces are exactly the size I need to secure the glass in the door.

For this Shaker wall clock I have chosen simple doors constructed with slip joints. This is consistent with many Shaker clocks in existence. More importantly, for a given rail and stile size, slip joints provide more glue area and are stronger. The rails and stiles on this clock are only 1 1/8”, so this added benefit is quite important.

Slip joints are basically a mortise and tenon with the mortises being open. The table saw and tenoning jig make cutting the open mortises and tenons easy and safe. I cut the open mortises first and then cut the tenons to fit. The jig has a fine vernier so that I can creep up on the correct tenon thickness.

Two of the stiles for the long door are 37” long, not a piece I would want to hold manually while guiding it through the table saw. This jig is designed to hold them secure, at perfect right angles, and hands safely clear of the blade. It is heavy and tightly fits the table saw groves so the cuts can be smooth and slow avoiding tear out.

I cut the tenons so they fit a little too tight in the open mortises. Then I final fit them with a shooting board and shoulder plane. This gives me a perfect fitting slip joint. The doors are crafted over sized, one quarter in wider on all sides. This leave me the ability to custom trim them to the carcass. A quarter inch may seem a little overkill, but it also allows for a little tear out on the ends of the stiles and mortises which will not remain after trimming.

The doors, after glue up but before custom fitting, are shown above right. Notice the rabbet shown on the back side of the long door. This rabbet provides and inset for the glass. Tuesday of this week I will be out to the wood yards picking out the figured wood for the back. After that only mounting hardware and applying the finish remains.

Trimming a piece requires careful attention to the joints. Even simple forty five degree miters can be tricky, sometimes requiring hand fitting with a block plane. But the most difficult part is cutting trim to the correct length; too long it doesn’t sit tightly against the backing and too short it leaves unsightly gaps.

I like to start by cutting the front trim to length first. To do that I cut the miter on the side pieces leaving them long. I clamp then in place and then cut both miters on the front trim, intentionally leaving it about 1/8” too long. I then sneak up on the correct length with a series of very fine cuts. As I approach the correct length I observe how the miters are coming together, and, if they need hand fitting I take thin shavings with a block plane and a shooting board. This is the equivalent of the dry fitting process that precedes all glue ups.

Once I have the front piece cut to exact length I glue it in place and clamp it. I let it sit for about an hour and then go back and apply the side pieces. The side pieces require special attachment because this is a cross grain situation. Normally I would glue the first two inches of the end that connects to the front trim, and use a sliding dovetail joint to hold the other end in place to allow for seasonal expansion. See picture above right.

However, this piece has relatively narrow sides, only 7 3/8” wide. Using a software tool to calculate the expected seasonal change for the Western MA area and cherry wood, I need only allow for about 1/8” expansion/contraction. Enlarge the picture at left by clicking on it and you will notice that this calculation is a function of stock type (flat sawn verses quarter sawn), area of the country where the piece will reside, current moisture content and species of wood.

Since the amount of movement is small, and the side narrow, I can use a simple elongated slot, screw and washer to allow for seasonal expansion. See the picture at right. Notice that I placed the screw toward the right end of the slot because most of the hot humid season is still ahead of us. I tighten the screw just enough to hold the trim in place, but not too tight, allowing the screw and washer to easily slide within the slot.

After the glue dries I like to inspect for glue spots that may have been left during the glue up process. The easy way to do this is to wet the surface down with mineral spirits. Mineral spirits does not raise the grain like water does and dries quite quickly. This procedure also gives me a preview of what the wood will look like once the finish is applied. I’ll again inspect the entire piece this way toward the end of finish sanding.

The completed and trimmed carcass can be seen at right. The trim seems a little weird without the doors in place but that will be resolved shortly. The slots you see in the clockworks compartment is for a 1/4” panel that will slide into place, and on which the clock dial will be mounted. Both the clockworks and pendulum compartments will have backs. I am in search of a highly figured wood for the pendulum compartment back, perhaps spalted maple, because it will be visible through the glass door. The doors will be contrasting black walnut.

The clock carcass is trimmed with a sandwich of quarter round and bull nose pieces. This requires two bits: I used a CMT Cove Bit #837.951.11 to form the 3/4” radius quarter round, and a CarbTech Triple Beading Bit #02-03 for the 1/8” radius bull nose. The Cove Bit has a bearing which controls the cut into the side of the stock.  The depth into the face of the stock the woodworker must set. With a bit this large I like to make a few passes, increasing the depth on each pass until I reach the 3/4” depth.

The CarbTech bit cuts three adjacent bull noses, each 1/8” radius. It does not have a bearing so you need to account for its depth of cut into the stock’s side with the outgoing router fence. I sacrifice the middle bead, cutting the stock in two right down the middle; an easy and safe task with a band saw. Next I use the drum sander, loaded with 220 grit sandpaper, as a thickness planer to finish the bull nose. A little glue and a few clamps and we have our trim.

Since I planed all the stock before milling, used 220 grit paper in the drum sander, and used sharp router bits, little or no sanding is necessary. If I do any sanding it is with a 320 grit paper to remove the raised grain resulting from the glue clean up. I am very careful not to destroy the edges that define the trim, and I perform this sanding only after the trim has been applied to the carcass.

Next I will apply the trim and build the doors. We are close to completion.

At this stage in the clock construction it is time to test the clock, pendulum and gong assembly to be sure no adjustments are needed to the seatboard or gong block. Making any adjustments later will be much more difficult. Also, I have been waiting for some time to hear the gong, not at all sure I would like what I heard once I heard it.

My clockworks are a Hermle 241-080. The instructions for assembly and adjustment received with the clock are for a different model that looks nothing like the works staring me in the face. I called the supplier and left a message requesting the correct instructions. No return call. I sent an email with the same message. I received an email with a PDF file of the same instructions I already had. So I read the instructions carefully and armed with that knowledge attempted mapping it onto my clockworks.

After a day of fiddling I managed to get the clock working. The main problem was that the clock would stop after five to ten minutes. The solution is what clock masters call “putting the clock in beat”. This is a process of adjusting the slip clutch on a crutch arbor until the tick tock sound is balanced. The instructions call out components such as verge, crutch, clutch, leader, escapement and suspension spring. Being a woodworker I have never noticed any of these components in the shop. It was all new to me. But with some perseverance I prevailed and the clock has run for more than a day now.

The gong sounds great, though it is awfully sensitive to adjustment. A tiny bit left, right, up or down and the sound is totally different. So I have decide not to glue the gong block in place until the clock is ready for finish. I may even devise an attachment method that allows position adjustments instead of gluing it permanently in place.

Next I will trim out the clock, add the pendulum and clockwork backs and build the doors. Stay tuned.

Gluing up the carcass of a project is a major project milestone in my mind. It marks the transition from preparing and milling stock to trimming and finishing. More importantly it gives me the first look at shape and size. I create my working drawings in 3D, which has many advantages, but one disadvantage over a mockup is that you are never really sure about the overall look until glue-up.

Like most woodworkers I never glue-up a piece without first dry fitting it. This accomplishes a number of things. First it lets me know if I need to trim a joint for fit. Second, it gives me a chance to practice the steps I will use in the glue-up, which uncovers all the tools and aids I will need, saving me from hunting down something while glue is setting up. Lastly, and most importantly, it helps me develop a glue-up strategy and sequence. Without this dry run a merely stressful step becomes a disastrous and disheartening one.

Most of the joints in this carcass are dovetails. I like to inspect them for tightness and gaps. I also check to be sure they seat completely. Dovetails will almost always go together smoothly if the pencil marks that mark the transfer of the tails to the pins are still visible. This is a check that can be made before the dry fit but it never hurts to double check.

Dovetailed carcasses are unique in that, while clamps are useful, and sometimes necessary to seat all the joints, clamps can be immediately removed. The dovetails are enough to hold the carcass while the glue sets up. This allows for easy checking and correcting for square.

Even with all this checking and dry fitting mistakes can still be made. After I glued up this carcass I noticed one. I have marked the outline where a hole is supposed to be in the picture at right below. This hole is intended to allow the pendulum and weight chains to drop from the clockworks compartment to the pendulum compartment. I should have milled this hole before glue-up. Fortunately, while more difficult, it is still doable after the glue sets overnight.

Next I will mill the clockworks and pendulum compartment backs, sand the carcass and backs, and permanently install the lower back before moving on to the doors. Stay tuned for more updates on this project.

One of the more important components in a clock case is the seatboard. The seatboard is the board on which the clockworks is mounted and secured. Its placement determines the vertical and horizontal centering of the hour and minute shaft relative to the clock face. It also determines the clearance, or depth of the shaft relative to the clock face.

The seatboard consists of a number of holes that must be accurately placed. Two small holes are for threaded pins that secure the works to the seatboard. When installed in the clock the seatboard itself is fixed (no mechanism for adjustment). The positioning of the works on the seatboard directly affects all positioning mentioned in the previous paragraph. So these holes too must be accurate.

Since this is a chain driven clock there are four larger holes that allow the chains to move freely and hang in the pendulum cabinet (lower section of the clock). These holes need to be large enough to permit “pulling” the weights once a week for winding and to ensure no interference as the weights slowly drop while driving the clock.

One rectangular hole is needed to allow the pendulum to pass through and swing. This hole does not require critical dimensions, simply enough room for clearance.

If you have been following this project on my blog, you know that the clock works for this project came with no documentation. I had to reverse engineer the seatboard design by taking very careful and difficult measurements of small, and deeply imbedded parts in the clockworks. I am sure you are asking yourself, “How can this be difficult? After all, there are only four holes we are talking about”. Well, let me assure you that positioning a 6” steel pocket rule inside the delicate works of a chain driven clock to make accurate measurements is all but impossible.

I meticulously took measurements and used them to create shop drawings. After milling my first seatboard and mounting the works, I made further measurements to test whether alignment in the final clock would be correct. This resulted in changing the position of three out of six holes.

I corrected the shop drawings, milled another seatboard and tested again. This time everything worked out perfectly.

Milling this component provided the first opportunity for me to use my new Supreme Drill Press Table purchase from Peachtree Woodworking Supply, Inc. It worked like a charm, allowing me to quickly, accurately and repeatedly drill the holes. For the larger holes I used a Forstner bit with a backing board to ensure no tear out of the opposite side.

The rectangular hole was a three step process. First I drilled two holes, near each end and inside the rectangle, and large enough to accommodate a sabre saw. Second, I used the sabre saw to rough out the rectangle. Lastly I used scrap wood pieces and double sided tape to form a a template for a template router bit to follow. The completed seatboard is shown above.

My current project is a Tall Shaker Wall Clock. It is a gift for my daughter upon her graduation from law school. She graduated a year ago and this gift is a little late. But hey, I’m not getting paid to do this ya know! Anyway, I just stared by preparing stock for the sides, top and bottom. I cut all pieces to final overall dimensions including thickness. When building a carcass using hand cut dovetail joinery it is especially important that all mirrored pieces (right and left side for example) are precisely the same size and perfectly square. Next I carefully choose the surfaces I want exposed and then mark the material to be sure they go together correctly. Carpenter’s Crayon is perfect for this purpose.

A hand cut dovetail joint requires quality hand tools. Like all woodworkers who work with hand tools I have my favorites and will stack them up against anyone else’s favorites. It’s kind of a religious thing. My choices appear in the picture at left. The dovetail saw, chisel and dovetail marker are all Lie-Nielsen. The dovetail saw is the progressive pitch model; it has fine teeth in the front for easy starting and more aggressive teeth in the back for rapid cutting. The dovetail marker has a 7:1 pitch (or approximately 8 degrees) which I use for hardwoods, and also serves as a square to mark vertical line for half pins. The chisels are just the right length and well balanced. Their weight is on the light side so that your fingers do not tire after hours of dovetailing and unlike Japanese chisels whose triangular top edge cuts into your fingers, the flat top edge of the Lie-Nielsen does not.

I like a light, hard rock maple wooden mallet. This one was recommended by and purchased from Nora Hall’s website. Nora Hall, if you don’t know, is an expert on carving. A small engineer’s square is ideal for marking the top edge with tail and half-pin spacing. I cut tails first and cutting perpendicular to the board face is critical for good fitting dovetails. The dividers are Groz with sharp points and are used to layout the pin and tail spacing by setting them to the width of one tail plus one pin and stepping the divider across the ends. Setting the dividers and marking other critical dimensions is accomplished with an accurate scale. I use the Incra Tiny T Rule which marks to 1/64″. The Lee Valley Veritas marking gauge makes quick and accurate work of scribing the pin and tail depth across the grain. And finally a well sharpened pencil with lead on the soft side for marking completes the tool set.

The sides of this clock are 51″ long. Cutting tails on this length piece can be quite a challenge. In the past I would have used my adjustable height bench raised to its maximum height to secure the board to eliminate chatter while sawing. With my new Lie-Nielsen bench I find the face vice holds the piece securely and its size and mass all but eliminate chatter making tail sawing easy. I still needed to stand on something for elevation. One of the stools I wrote about crafting as Christmas gifts for our grandchildren came in handy for this purpose. I reposition it frequently so that my stance and arm are appropriately aligned to make the cuts. I use this stool again when removing the waste between the tails with the fret saw as shown at left.

There are two aspects of cutting tails that is critical to good joinery. The first I mentioned earlier is cutting perpendicular to the face of the board. Failing to do so will leave unsightly gaps, poor glue joints and weak mechanical joints. The second aspect is to stop the cut at the scribe line. Going past this point will show and leave a sloppy appearance, not one a craftsman wants to project.

There are a few aspects of tail cuts that are not critical. The angle of the cut is nominally 8 degrees from vertical, but this is not critical. Neither is the width of the gap (pin width). Machine cut dovetails would all be perfectly angled and spaced, but then they would look machine cut. The human is not a machine. Hand cut dovetails are beautiful precisely because they don’t look machine cut; they are all slightly different, adding to the beauty of the piece.

The pins are a little more difficult. First, the pins are traced from the tails by laying the tail board on the pin board, aligning them perfectly perpendicular and at the correct depth and tracing the pins from the tails with a sharp pencil or knife. I prefer a pencil because I want to saw on the waste side of the pencil marks, that is, leaving the pencil mark which is actually part of the pin. This I can see clearly with pencil marks. However, a knife mark tends to draw the saw blade into its kerf leaving me less control. I complete the layout using the dovetail marker being sure to mark the waste area with Xs as shown at right.

There are critical aspects of pin cuts that must be adhered to. Cut on the waste side of the pencil mark, but aligned as closely to it, and along it as possible. Cut straight down using the vertical lines as a guide. Stop at the scribe line on both sides of the board. Paying close attention to these will assure snug fitting joinery – assuming you also cut the tails correctly. The trick to hand cut dovetails is being able to cut vertically and to follow a line. Once those two skills are mastered you can hand cut dovetails that go together the first time, every time.

It helps to cut vertically if your piece is mounted in the vice plumb. The shoulder vise on my Lie-Nielsen lets me quickly accomplish this by holding the piece flush against the vice as I tighten it.

After making all the vertical cuts I am ready to remove the waste. This is done in two steps. First, clear the majority of the waste from the pins by cutting it away with a fret (or coping) saw. I twist the blade in my fret saw to about forty five degrees with pliers. This allows the saws frame to clear the board as I cut. Turning it ninety degrees to the frame would make starting the cut near impossible. When sawing I try to stay as close as I dear to the scribe line leaving just enough to support the chisel cleanup that will follow. How much you leave depends on your experience and courage. If you are just starting out stay at least an eighth of an inch from the scribe line. Be sure you cut evenly front to back. You don’t want to cut close to the scribe line in front and below the scribe line in back. Judge this carefully. After a while it becomes natural and requires no special attention.

The second step in clearing the waste is to clean up the material left by the fret saw. I perform this step with a very sharp chisel. Depending on how close I cut to the scribe line will determine how many cuts along the scribe line I will need to take. If you are doing this and you leave a quarter of an inch for example, you will want to make at least three passes as you approach the scribe line. The last pass should be no more than one eighth inch. Less is better. I hold the chisel slightly passed vertical such that the waste is cut angled into the board. The end grain serves no purpose in the joinery; only the faces of the pins and tails are used to form both the mechanical and glue joint. I check with a small engineer’s square that the material is removed such that the scribe line on each face is unimpeded by material that might project passed them.

The final joinery set is shown at right. Note that you can still see the pencil marks on the pins. As mentioned above they are part of the pin material since the tail was used as the mask to form the pins. Also note that the tails are cut perpendicular to the face of the tail board and the pins are cut straight down – that is vertical to the board. These pins will go together for the first time during glue-up with no dry fit required.

I have a confession to make. You can see that some of the end grain in the pin boards was chipped out. If my chisel were as sharp as it should have been this would not have happened. My chisel was sharp when I started out on the tail boards and I should have stopped to sharpen it for the pin boards. However it was close to dinner time and I was almost done so I plugged along. The small white sin here is that the end grain does not play a part in the joinery and will not be seen. So I can be forgiven, though it is not my usual practice. There, I feel so much better now that I got that off my chest.

If you are just starting out with hand cut dovetails, or haven’t yet started but would like to, I would highly recommend purchasing Rob Cosman’s series of video tutorials. I have been cutting hand dovetails for ten years now and consider myself experienced. But I still purchase nearly every tutorial I can to see how the masters do it so that I can learn and improve. Frank Klausz is probably the dovetail king with Rob Cosman a very close second, but Rob’s videos I find to be the best tutorials on the market. Don’t shy away from hand cut dovetails. Innate skill is not required. Anyone willing to practice sawing vertically and to a line can master them.

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Note: Before reading this tutorial see Notice in the last paragraph.

In this tutorial I am going to show you how to draw the quarter round and bull nose trim that make up the bonnet of the Shaker Style Chain Driven Wall Clock posted on my Free Plans page. The front view dimensions and trim detail dimensions are shown in the picture at left. Click to enlarge the picture and study the dimensions.

The circle center highlighted with an arrow in the picture is an important reference point. It is the same circle center used in Part 1. If you recall it was 7/64″ above the bottom front edge of the stock. In this drawing it lies on the front most plane; that is the same plane as the 1/4″ flat surface of the quarter round trim. This will be obvious soon.

Notice that the circle radii are 1/32″ greater than either a whole inch or inch and a half. This is to allow a 1/32″ gap (clearance) between the top of the door’s arch and the bonnet. The bonnet trim is made of two pieces: a quarter round trim made from 1″ by 1 1/4″ stock and bull nose trim 1/4″ thick by 5/8″ wide.

The picture at right shows the side view of the bonnet trim. Note it extends from the front most face back 9 3/8″.

There is symmetry to this bonnet on either side of the vertical center line, and I am going to make use of that symmetry to reduce the amount of work I need to do to create these components. I am going to start by making the side quarter round. The star of this show is the Follow Me tool. First, using the Line and Circle tools I make an outline of the quarter round and a path to follow with the Follow Me tool. See picture at left. I used the Rectangle tool to make a 1 1/4″ square in the Red/Blue plane and then used the Move/Copy tool to move the bottom line up 1/4″. This leaves room for the bull nose trim later on. Starting at the corner of the rectangle closest to the origin I draw a 3/4″ radius circle.

One point I made in Part 1 and want to stress here is that when using the Circle tool always strive to have the second point (the none center point) reside on an edge, preferably one that aligns with an axis. It is especially true in the modeling of trim like this where curves constructed with circles will end up coming together. This technique does not always produce a perfect seam, as we will see shortly, but it does create a much better seam than a non-perfect circle otherwise would (remember these are circles made of polygons).

After some erasing using the Eraser tool I get the picture at right which shows a partially completed quarter round using the Follow Me tool. I complete this part by extending it to the end of the 9 3/8″ path. Then, selecting all primitives by clicking three times on the quarter round, I create a group (no need to create a component at this point, although I could if I wished).

The side quarter round and the front quarter round will meet in a miter joint of 45 degrees. So now I will create a slicing plane. Enlarge the picture at left and study it. Starting at Point 2, the corner, I create a 45 degree construction line across the top. Now, starting at Point 1, the intersection of the construction line and the edge, I draw a line to Point 2, continue the line to the Origin, continue on to Point 3 which is located with the help of the inference engine, and end back at Point 1. I have created a rectangular plane with one edge on the Blue axis and 45 degrees to the Blue/Red plane. The slicing plane encompasses and slices through the quarter round.

To complete the part I will Explode the quarter round Group and select both the quarter round AND the slicing plane and choose Intersect/Intersect with Model. After clean up with the Eraser tool I select all primitives of the quarter round and create a Group. The result is shown at right.

This side quarter round is longer than half the front width of 14 1/2″ (see top dimension in the very first picture above). So I can use a copy of this part to form the front quarter round. Using the Move/Copy, Rotate, and Flip Along/Group’s Green tools I place the front quarter round. At the same time I will use the Tape Measure, Line and Circle tools to create the construction lines, quarter round outline and a path for the quarter round arch. See Picture at left. Enlarge the picture and note that the large circle is constructed using 60s as the side parameter for the Circle tool and the small circle uses 24s.

Now I can erase a few lines and with the Follow Me tool produce an arched quarter round that is one quadrant of a circle. It is important that I use the full quadrant so that the arched quarter round goes completely through the front quarter round. This will be obvious in a moment. The picture at right shows the single quadrant of arched quarter round. Leave this part as is for now. Do not Group it or make it a Component. The difference in color can be corrected easily later. For now it provides a contrast that is actually helpful.

At this point I want to create a slicing plane just as I did for the side and front quarter round miter joint. But this miter joint will not be 45 degrees (when the drawing is completed you can measure it and find it to be 58.4 degrees). To create the slicing plane with the correct miter angle I need to draw two very critical lines. See the picture at left. I used the Rotate tool to get this view of the backside. Zooming in very close and with the Line tool I draw lines from Point A to Point B and Point B to Point C. It is necessary to zoom in close because the circles are made of polygons and the inference engine could get confused by their intersections. Now I want to complete the plane as a rectangle that will encompass the intersecting quarter rounds. An easy way to do this is to select line BC and using the Move/Copy tool, move a copy of BC forward (toward the face) along the Green axis 1 1/4″. I call this line B’C’ where points B’ and A now coexist. Now it is just a matter of creating line C’C, zooming in to be sure I get the correct points. If I am successful a surface appears. If a surface does not appear the four points of the desired rectangle are not coplanar, indicating I made a mistake.

I will be using this slicing plane twice; once for the arched quarter round and once for the front quarter round. With the Select tool I click twice on the slicing plane’s surface and this selects just the slicing plane. With the Move/Copy tool I move a copy of the plane to the side. I also temporarily move the front quarter round back so I can work on the arched quarter round. See picture at right.

Now I triple click on the arched quarter round and select it AND the slicing plane intersecting it. I choose the Intersect/Intersect with Model to form the miter cut. After some clean up with the Eraser tool and creating a Group I have the picture at left. This picture has been rotated so that you can get a good view of the miter. Be sure when you are doing the clean up that you zoom in very close to erase only the appropriate lines. If you make a mistake use the Undo to go back and correct your mistake immediately.

Now I can move the front quarter round back in its place using the Move/Copy tool. This requires a careful zoom as well. Using the intersection of the front quarter round and the arched quarter round as a reference I move the saved slicing plane back into position. Not to harp on this too much, but because circles are involved, this requires careful zooming too. This is the last time I will mention the zoom requirement, but be forewarned.

Like before I move the arched quarter round out of the way. I right click and Explode the front quarter round, and then I click three times on the slicing plane to select it AND the front quarter round. Again I use Intersect/Intersect with Model, then clean up the unwanted primitives. Next I Delete Guides, Group the front quarter round again and move the arched quarter round into position. See picture at left.

There is one more piece of clean up that I need to do. Follow Me works similar to Push/Pull in that it Pushes/Pulls a plane normal to the path along the path. In SketchUp everything is made of straight lines; we have already seen that with circles. When Follow Me follows a curved path it is following a bunch of straight line segments. It essentially Pushes/Pulls planes that are normal (perpendicular) to the path segments. This can create problems at the beginning and end of the path because the Follow Me tool must create a surface normal to the path at the end segments. Note in the picture at right that even though I started out with a surface outline of the quarter round that was parallel to the Blue/Green axis, when I recreate that plane I see that the end surface is no long parallel to the Blue/Green plane. Follow Me has created a normal plane. I therefore use this newly created parallel plane as a slicing plane to restore the original orientation.

Now I have all three pieces of the quarter round trim completed. I can make a flipped copy of the arched quarter round and add it to the original to form a two quadrant arched quarter round. This simply requires that I explode both pieces and clean up the seam where they come together. Then I can make a component of this part. Similarly, I can select the side quarter round, explode it, Reverse Faces and make a component of it. Finally I do the same to the front quarter round.

I can use the exact same process outlined above to create the bull nose trim. However, I will leave this to the student. The final results are shown at left.

In the next installment of this tutorial I will use the Office Table model available on my Free Plans page, and included in my Gallery, to show how I created the rounded edges of the table top. See you in Part 3.

Notice

With this tutorial I am trying something new. I am capturing the drawing of each tutorial installment, along with voice instruction, in a .AVI file. Anyone wishing a copy can go to my Contact page and email me to request one. Be sure to provide all information, including mailing address, necessary for me to get the file to you. I will charge a nominal fee of $6.00 US to cover the cost of the mailing envelope, mailing fees, DVD and jewel case. I will put as many parts (tutorial installments) on one DVD as I can and still charge only $6. Parts 1 & 2 of this tutorial fit on one DVD. I don’t know how the rest will divide up. These .AVI files are not professionally created files, but I believe you will find them very instructional for those who prefer visual learning.

Also, a Word version of this tutorial, as well as a smaller file size PDF version, is available by clicking here.

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