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Elliptical Ceiling Medallion

Designing with a little help from my computer

A little while ago, a customer called wanting to do something in their living room to make it feel more formal, a bit “French country.” The homeowner presented me with pictures of rooms from design magazines. “Can you make my living room look like this?”

Sure I can!

The new fireplace mantel

The living room was 27 feet long, with a ceiling just under 8 feet. The molding around the windows was simple 2-in. colonial. The baseboard was 3-in. To make matters worse, someone had made a poor attempt at installing crown molding. The room felt like a squat blank box. Everything had to go.

I constructed a virtual model of the room in Chief Architect. Once the virtual model was done, I was able to work with the homeowner to refine her design. The program allowed me to work out the size of the mantel, and molding details before any money was spent.

The major elements of the redesigned room would be a new fireplace mantel, a ceiling medallion connected to built-up crown molding via four radial spokes, new window trim and baseboard, as well as shadow boxes on the wall.

(Click any image to enlarge. Hit your browser's "back" button to return to this article.)

The ceiling was just under 8 feet high, so the medallion could not have much depth. It would need to be flat against the ceiling.

Building the Ceiling Medallion: Layout

In all honesty, it would probably have been smarter to have a mill shop make the medallion on a CNC machine. But that would not have been as much fun, and I was up for the challenge.

Rough-sketching the medallion on the ceiling was the first step. This gave me and the client a chance to refine its size to fit the scale and feel of the room. I wanted to make the ellipse out of 1×8 poplar cut-offs left from the mantel and baseboard. (I just hate to throw out wood.) A CAD program made it very easy to layout the length and angle of each of the pieces that would form my final shape.

It was while I was figuring out the angels that I realized I didn’t have to layout an entire ellipse, I just had to do a quarter of it and repeat it four times.

Creating an Ellipse in AutoCAD

Drawing an ellipse in AutoCAD is easy, since the program allows you to enter exact measurements. All measurements are given in X,Y format from the origin. (Unless you are in “polar coordinate” mode, but that is a different article.)

To create the ellipse, you need to know two measurements: the major axis and the minor axis. In my case they were 90 in. and 60 in., respectfully. From these lengths, I derived the three points needed to form the ellipse: My starting point, simply (0, 0), the end of the major axes (90 in., 0) and end point of the minor axes, (45 in., 30 in.). 45 in. to the right of the starting point and 30 in. up the Y axes.

To start, activate the ellipse icon. Enter the three points of the axes as (0, 0), (90 in., 0) and (45 in., 30). That takes care of the ellipse representing the outside of our medallion.

To make the inside line, I used the “offset” function to create another ellipse 3.5 in. smaller. Entering the letter “O” on the keyboard activates the offset function. A prompt appears asking for an offset distance. In this case I enter 3.5 in., the width of the medallion. Click on any point of the ellipse, then click on the side where you want the new ellipse to be formed. Now you have the inside of the medallion.

The ellipse we just created represents the final form, after everything is cut and shaped.

Since the blanks I would use to cut out the medallion were 7 1/2 in wide, I formed two reference lines: 2 in. bigger, and 2-in. smaller (2 in. + the original 3 1/2 in. + 2 in. gives us 7 1/2 in. — the width of my lumber).

Starting at point A,

draw lines not quite tangent to the outside of the primary medallion.

This will determine the length of each segment. Continue this for the entire quarter of the ellipse.

Next, use the offset function to create the inside edge of each segment.

Lastly, I connect an intersecting line to form each block. The length and angle function of AutoCAD gave me the lengths and angels of each segment.

Trust me, you can perform the entire feat in less time than it took me to write this explanation. With one hand scratching my dog behind the ears…

…I still did the CAD layout in less than 8 minutes.

Here’s a video which shows the whole process:

Time to ruin some wood

With measurements in hand, I cut all my blanks on the miter saw. Then I laid them out in the rough form of the finished medallion’s outline, making sure that all the cuts where right and the joints would be tight. My plan was to use pocket screws to clamp the pieces together.

While the medallion was still laid out, I marked where I wanted the pocket holes to go on each piece. This would help me avoid cutting the holes on the finished side. I also put reference marks on the pieces so that I would know how to put them back together.

The Kreg Foreman made quick work of the pocket holes.
I glued up the pieces of the blanks and used the pocket screws to clamp them together.

I had four quarters of a roughed-out ellipse. Time to create the final form.

The Trammel

A trammel

A trammel, or ellipsograph, is a device used to draw or cut an ellipse. It consists of an arm with two pivot points “trammeled” in channels that are perpendicular to each other.

There must be a hundred articles and YouTube videos on how to build a trammel. My trammel was inspired by, if not outright stolen from, Jim Chestnut’s website. (I also feel the need to give some credit here to my 9th grade geometry teacher, who first showed me a trammel.)

To create my trammel, I cut a 1/4-in. rabbit 3/8 in. deep in the center of two 1 x 4s.

The 1 x 4 formed the rails of the trammel. I screwed a 1-in. x 4-in. x 5-ft. board to the base of my router to form the trammel arm, and drilled two 1/4-in. holes into it for the pivot points. The first hole, closest to the router, corresponds to half the minor axis of the ellipse (30 in.) and the second hole corresponds to half the major axis (45 in.). I pushed 1/4-in. router bit spindles into these holes. A good coat of butchers wax on all the parts allowed me to move the arms smoothly. I screwed the ellipse blanks to my work table and made some reference marks to their exact location, so that each of the four blanks would be cut exactly the same.

I like to let the router do the work and take my time. I discovered (the hard way) that pushing the process only leads to mistakes. The edges were a little rough with router marks, but a spindle sander made quick work of finishing them off. I stacked the parts, and used screws to clamp them together. Sanding all the parts together in a stack helps to average out the imperfections.

I laid out the ellipse on the floor again to make sure that it really was an ellipse, and that the four quarters lined up.

 

Applying trim to the edge

The design called for an OGEE trim around all the elements of the ceiling—the top of the crown-molding, spokes, and the medallion. I considered many strategies for making this detail on the medallion, including using different router bits, and cutting the ogee edge into the blanks, or even buying the curve molding attachment for the William-Hussey molding machine. In the end, I settled on the idea of gluing the molding to the blanks.

The problem was that the molding, which measured 3/4 in. x 3/4 in., was much too thick to bend. To accomplish my goal, I needed to “laminate” the molding in strips to the blanks. I cut strips of poplar 1/4 in. thick and stacked three together vertically, to give me the width I need for the molding. Masking tape along the back of the stack bound them together into one piece.
Once taped, I fed the stack through my William-Hussey Molder, which cut the profile.
The resulting strips of molding were easy to bend and form around the blanks.

I quickly discovered that I could not glue all the pieces to the medallion at once, as the clamps crushed the small outside edge. So, instead, I glued up the first two strips of each molding piece, and used every clamp in the shop (see photo, RIGHT). The next morning, I removed the clamps and glued the final edge strip. This piece was so small and flexible that tape worked instead of clamps.

The last step was to fill and sand any imperfections.

With hindsight, I should have cut some gluing blocks in the shape of the arches. This would have made the gluing process much easier.

Installation

I assembled the medallion in the field with dominoes, and nailed it to blocks I had set behind the drywall. Lastly, I installed the radial spokes and OGEE molding along the spokes and crown.

Finished and painted, the medallion, mantel, and trim made a new room that my customer loves. Now I’m talking to the neighbor about their living room.

Other than a check, the few things I walked away with from this project were: first, a greater reliance on CAD for layout and planning of even a small job. And second, the knowledge that I can make flexible molding with my overhead molding machine.

•••

AUTHOR BIO

Bill Hillman is the owner of William Hillman Carpentry LLC in suburban Philadelphia. His company specializes in both major and minor home renovations, and custom finish carpentry.

Bill is a fourth generation carpenter who likes to joke that he bleeds saw dust. “As a baby, I didn’t have a rattle, I had a hammer; and it wasn’t a toy hammer!” After graduating from Penn State University in 1991, with a degree in Labor and Industrial Relations, he worked for a political consulting firm running political campaigns. It didn’t take long before the smell of wood pulled him back to his roots and he reformed the company he began in college.

Bill’s work has won several awards from his area NARI (National Association of the Remodeling Industry), and has been recognized by the local newspaper’s annual awards. He has also been a guest on the local Fox TV News affiliate, discussing home renovation projects.

Bill lives in Ardmore, Pennsylvania, with his wife Teresa, their boys, Billy and Jack, and their dog and cat. In addition to his work, and being a husband and father (and T-ball coach), Bill enjoys fishing, biking, and grilling.

Comments/Discussion

30 Responses to “Elliptical Ceiling Medallion”

  1. Gary Katz

    Bill,
    GREAT article. There are so many ways to skin this cat (I hate that saying!). We’ll be publishing more articles on laying out and cutting ellipses, but your approach is certainly a good one, especially for finding the angles and lengths for the molding blanks. That’s got to make bricking up the molding a LOT easier.

    Thanks for contributing,
    Gary

    Reply
    • Bill Hillman

      Gary, thanks for the kind words. It did make setting up the blanks easy.
      I read your comment out loud and my cat, Bailey, stood up, turned – tail high – and walked out of the room. I think that was a comment….
      Bill

      Reply
      • Gary Katz

        We work with a LOT of “bricked up” moldings, too, that are end-grain glue-ups, and we’ve never had trouble with them, especially radius casings on doors. I know Jim is right, though. Most of the mill shops we work with put biscuits in the joints–it’s not hard to keep them inside the edge lines of the molding. Since you have those miters worked out so nicely, dominos would work, too.

        Gary

        Reply
        • Bill Hillman

          Gary,
          One of the enjoyable aspects of writing this was the time spent reflecting on the techniques I used in the process of building the ellipse and, of course, what I would do different. The feedback from everyone has been great and given me much to think about.
          Bill

          Reply
  2. Jesse Wright

    Bill,

    Thank you for the article! Im impressed with your layout technique. I’m a Sketchup modeler, and I have never used CAD. I could see where I may need to learn this because that is really fast, and easy. Just as simple as SU.
    Also that room is beautifully designed. Your thought to timeless detailing is commended.
    What a great contribution.

    Jesse

    Reply
    • Bill Hillman

      Jesse,
      I love Sketchup. But I think it has its limits. For doing geometric models I believe Cad can’t be beat. I still use version 2000. Ten years old – – I got it real cheap. I don’t design building with it so I would never pay for the up to date version. Cad-lite is also a great option. It does everything I need it to do. For 3d mock-ups I still like shetchup. And the sketchup models can be imported into Chiefarchitect. We don’t care just one type of saw to a job – do we.

      I’m glad you liked the room. I’m very proud of it.

      BIll

      Reply
    • Mark

      Jesse,

      There are a couple of utilities that make doing this job super easy. First is the OWES.rb script that creates segmented ellipse, (or circles), and the second is the dim_angle.rb script to define the measured angle of the segments. The Dim Angle plugin is found at http://rhin.crai.archi.fr/rld/plugin_details.php?id=110 and the segmented ellipse plugin can be found at https://docs.google.com/leaf?id=0Bw8zdmaKDWIfZjE1MGMzZjMtZTM3Yy00NjI3LWFhYzktMDUyMGNkMWZjYTcx&hl=en&authkey=CKmvqYAP

      To make the segmented ellipse, I simply entered the parameters into the EqSegs plugin “45, 30, 24″, this creates a ellipse that measures 90 x 60 with 24 segments. Then it was just a matter of using the offset tool to create the boards width, I used 2 1/2″ on both sides of the ellipse to get a board width of 5”. To get the angles of the segments, pull up the Angular Dimension tool and select the 3 points you want the angle of. Here is a simple screenshot.

      [img]http://www.thisiscarpentry.com/wp-content/uploads/2011/02/Segmented Ellipse2.jpg[/img]

      Reply
  3. Kevin Zale

    Bill,
    Great looking room and an excellent article. It is nice to see approaches to problem solving using a little head-scratching instead of just looking for a tool that does it for you. Thanks for sharing.

    Kevin Zale

    Reply
  4. Dave Millman

    Bill,

    Great design and workmanship!

    It’s hard to get a sense of the finished room from the first and final photos. My only question is, do the spokes add or detract from the design? It almost looks as if the room would look cleaner and the ellipse more stunning without them.

    Thanks for the article!

    Reply
    • Bill Hillman

      Dave,

      It tough to get a real since of the room from photos. But IMHO the spokes make the ceiling by tying all the eliminates together.

      BIll

      Reply
  5. Gregory Wesley

    I am a Carpenter turned Designer since “03” and Bill, I must say that your article had me longing for my saws, clamps and nail-guns only because you made it look so easy. Learning to use Auto Cad and Turbo Cad back in the 90s made me look a lot smarter than I am on many a job sites. Sometimes, in some of my plans, I also draw a “how to” sheet to help out some of these youngsters. This article will help me to help some of the up and coming Carpenters/Contractors add a bit more piz·zazz beyond the ol’ chair rail for some their clients.

    Thanks BIll

    Below if it’s allowed is a link for Double D a free and very good CAD program and you also download the user manual as well.

    http://www.doublecad.com/Products/DoubleCADXTv3/tabid/1100/Default.aspx

    Reply
  6. JesseWright

    Bill,

    Im also interested in what color all the trim is painted? Its got a real historic colonial feel to it.
    Also the spokes IMO set off the ellipse. Great choice! It really brings the room together.

    Reply
  7. Tim Raleigh

    Bill
    Thanks for the article. Great presentation.
    Do you think it is easier to draw/present the whole room in Chiefarchitect over say Sketchup?
    In your opinion are the main advantages of Chiefarchitect over Sketchup for room design?
    Can you do an article on the mantle design? I think it really looks great in the room.
    Tim

    Reply
    • Bill Hillman

      Tim.

      I think Chiefarchitect (CA) is much easier when it comes to designing the entire room. It can be done in just a few minutes. CA is specifically designed for structural work. With a few key strokes I can change any of the moldings in the room using products from Windsor One or any of a list of manufactures (or, as in this case, my own design) . It is worth playing around with. The program’s price is a little steep, but, like any good tool, if mastered and used right it should pay for itself. As I’ve said, Sketchup has its place; In fact I designed the fireplace in sketchup and imported it into CA
      I really believe there is a direct correlation between the finished product and the level of detail in plan. All those devils can be worked out before any wood is wasted.
      Also; its taught to sell an idea in your head that your customer can’t see.

      I like to do the article on the Mantle. Let me see what the powers in control say.

      BIll

      Reply
      • Tim Raleigh

        Thanks Bill.
        Yep, definitely easier to sell a design when they can see it and even look around the design like you can in Sketchup. I agree, when you have built the project before you build it you know where the problems are and how to solve them.
        It’s good to know that you can import Sketchup drawings into CA.
        It would be great if you could do a design through to finished install “expose” of the mantle. Actually I am more interested in the design process, how you interpreted the clients request and how that directed your choices etc. That may not wash with the “editorial committee” though :).
        I know it’s a lot of work so it would be much appreciated.
        Thanks again. I will try CA.
        Tim

        Reply
        • Gary Katz

          Tim,
          Actually…the “editorial committee” thinks that’s a GREAT idea! Maybe you could pick up that ball and run with it. Sounds like the makings of a neat article.
          Gary

          Reply
          • Bill Hillman

            When I first thought of writing about this project I had envisioned doing two parts and the mantel would be the second part. Tim it sounds like I’ve got the green light to pick up that ball. I’ll start this week.

            Bill

  8. Rob Mulchinski

    Bill,

    All I have to say is thank you. You have given me some great ideas for an upcoming job. I have some elliptical moldings to be fabricated for windows in a new kitchen installation. Great work the pictures look very impressive.

    Gary,

    THISisCarpentry has really been a great discussion forum and tool for everyone.

    Thank you both.

    All the best,
    Rob

    Reply
  9. Jim Baldwin

    Bill,

    Fun read and great video presentation. I am currently wrestling with “Draftsight” which is another CAD freebie. I can see right away that the best part about CAD is that it gets me off my knees. Most of my drawings have to be full-sized and wind-up occupying the whole floor. With CAD I can now draw infinite lines… (I’ll bet boat builders really appreciate CAD. Traditional “lofting” really does require as much drawing floor space as the size of the vessel.)

    I must say…
    I’m not quite sure about your chosen construction method, you’ve made this entire elliptical frame from a lot of butt-jointed pieces of scrap. End-grained, butt-joints held together with a lot of pocket screws may work but can’t honestly be considered classic or accepted joinery. After all, a hot ceiling is an acid test for any good wood joints let alone marginal ones.

    BTW, the actual “tape trick” for shaping a bundle of strip-stock into bendable molding is thin-film double-sided tape stuck directly to the facings.

    Reply
    • Bill Hillman

      Jim,

      I’m glad you enjoyed. I’ve never used “Draftsight” , I’ll have to check it out.
      As for my assembly method; I’ve found that a good glue joint works just fine. The cross section is only 3.5 inches and the finished product was sealed on all sides. I understand there are a number of ways this could have been done. I could have spent tripled the time I had in building the piece. The question is would it have changed the end result enough to justify the cost? The budget for the for the project was already tight. I think all carpenters have to do that balancing acting looking for the method that will provide the highest quality at the highest profit.
      Bill

      Reply
  10. Jim Baldwin

    Bill

    Yes everything is a balancing act and I applaud you for making full use of the lumber tails and doing a great job of it too! If you hadn’t had the spare wood pieces however you might have approached this a little differently?

    A typical ellipse is normally divided into no more than 4 or 6 segments. Simple butt-joints are doweled and the edge molding detail is usually shaped directly onto the pieces themselves. The trammel is used to make the shaping templates only. The intersected spoke-molding is butt-mitered into the outside edge. As far as time is concerned, I believe this would been (by far) the most economical approach.

    Your unique method however demonstrates great resourcefulness (with your resources) and flexibility in design. Anyway, the real gist of your article is focused mainly on CAD and to that I bow to your experience and thank you for the insights. (I still haven’t figured out how to draw a perpendicular line from an angle!)

    BTW, I believe I have a submitted article coming soon here and I can already tell you that your fine presentation puts mine to shame.

    Reply
  11. James Fackler

    Nice work. I can’t help but ask why you didn’t use MDF for the medallion. The amount of work to get to the stage where you route the blank seems excessive, not to mention all the joints and sanding. With a sheet of MDF you could have a seamless piece that would paint just fine. I understand the purists resistance to using MDF, but this situation screams for it.

    Reply

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