Ellipse Like Sugar...

[Prashun Patel]

I'm making an elliptical top coffee table for my sister. I'd like to be able to cut the top without having to invest the $$ to buy a router jig or the time to build one.

Is it possible to draw this with the pencil/two-pin/string method and then free hand it on the bandsaw? Anyone have a better method?

Perhaps I should do this on 1/4" hardboard and then route to the template?

Kudos to anyone who gets the above reference...

[Kent A Bathurst]

Draw on the 1/4" hardboard with the 2 pins and string. Bandsaw, and rasp/sand to line.

Screw hardboard to underneath side of top, and free hand on bandsaw. Don't color inside the lines.

Finish with top-bearing router bit using hardboard as template.

[Jamie Buxton]

You might want to distinguish between an ellipse and an oval. The ellipse is a tightly-defined mathematical shape. An oval is more loosely defined, and can be kinda elliptical. If you need a true ellipse, well, you've got to construct it carefully with a jig or the like. If an oval is good enough, and if you're using solid lumber, yes, you can draw it freehand or any other means you like, cut it with a bandsaw or saber saw, and belt-sander it to clean up the saw marks. Then you ROS it to clean off the belt-sander scratches, and you're good to go.

Me, I think true elliptical tables look too pointy on the ends. I like to make the oval less pointy.

..but you're gonna have to 'splain the sugar thing...

[Jerrimy Snook]

Is that "Lips like sugar. Sugar kisses" by Echo and the Bunnymen?

[Prashun Patel]

Thanks for the advice; hardboard template it is.

Yes, Echo and the Bunnymen. 80's teenagers of the world, UNITE!

[Todd Burch]

..but you're gonna have to 'splain the sugar thing...

I'm w/ you Jamie. I was a teen in the 70's.

[Peter Quinn]

Depending on the size of the eclipse and radii involved it may be easier to cut the template with a jig saw IME, than fair the curve by sanding' then routing.

[Kevin Bourque]

Okay, I just got the joke.

[Bruce Wrenn]

Only make a quarter template. You can flip it to get other quarters, and they all will be the same.

[Frank Drew]

For a one-off I'd definitely do this freehand, either with a bandsaw or good quality jig saw, the latter probably easier for a biggish table. With either, if you cut carefully cleanup shouldn't be too onerous.

[Prashun Patel]

I like freehanding on the bandsaw and then cleaning up with hand tools. The problem is this is a fairly formal looking table, so I want the edges crisp. Personally, I think it'll be easier to fair a 1/4" hardboard template "perfectly" vs a 7/8" ash panel.

Bruce, why do you recommend a quarter template? Doesn't seem any easier than making a full one...?

[Kent A Bathurst]

Personally, I think it'll be easier to fair a 1/4" hardboard template "perfectly" vs a 7/8" ash panel.

Also - easier to fair a mulligan, or two, on the hardboard............not that you nor I would ever need that option in reserve. ;)

[Jim Becker]

I'd also go with the template routing method since as mentioned, it's easy and "cheap" to futz around with some 1/4" hardboard or MDF for awhile to "get it perfect". You also end up with a reusable template for the future if you choose to keep it around. And as you probably have experienced or observed, a template-routed shape gets you much closer to a finished product without having to balance a heavy workpiece against a stationary sander, etc.

[Bill Huber]

I am not sure you can get to the link but Pop Woodwroking had "How to draw an ellipse" it takes you step my step.

http://www.popularwoodworking.com/woodworking-blogs/editors-blog/elliptical-shapes-using-simple-geometry-%E2%80%93-video?et_mid=560220&rid=3259415

[Jim Tobias]

Prashun,
I agree with the others that the template idea is the best if you are only doing one of these. I am in the process of making an elliptical coffee table and matching side table(but smaller ellipse) and so I spent the $s to buy a jig from Woodhaven. I needed it to cut patterns for aprons as well as top. It is a nice set up, but after seeing how it works, I think you could buy the parts and make it pretty quickly. Just another $.02 worth.

Jim

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[Prashun Patel]

Jim, what's yr design? I was planning to do a rectangular apron underneath.

[Jim Tobias]

Prashun,
This is a custom/commission piece. It was a design from a compilation of pictures from the customer. It is to have a black lacquer finish. I also have to give a shout out to Dave Richards for helping me with drawing the curves. Sketch Up is a never ending learning curve!!
The top also has an beveled glass insert and apron and legs are curves. Lots of laminating.
Jim

233772

[Damon Stathatos]

A funny thing happened to me on the way to the forum this morning.

I somehow got on the Popular Woodworking junk mail list. Coincidentally, today's version was titled, 'Master Ellipses in 4 Minutes.' I dutifully emptied my junk mail and then, over to SMC where this post jumped out at me. Anyway, here's the link to mastering ellipses in 4 minutes:

http://www.popularwoodworking.com/woodworking-blogs/editors-blog/elliptical-shapes-using-simple-geometry-–-video?et_mid=560220&rid=233778783

Hope it helps.

[Kent A Bathurst]

Prashun,
I agree with the others that the template idea is the best if you are only doing one of these. I am in the process of making an elliptical coffee table and matching side table(but smaller ellipse) and so I spent the $s to buy a jig from Woodhaven. I needed it to cut patterns for aprons as well as top. It is a nice set up, but after seeing how it works, I think you could buy the parts and make it pretty quickly. Just another $.02 worth.

Jim

JIm - that is definitely cool.

How do you like it? Any issues where the sliding tabs cross the tee-track center intersection?

[Jim Tobias]

Kent,
So far I like the jig. I have used it to draw the ellipse for the top and also the shape(inside and outside lines for thickness of apron) for the aprons which I have made forms and laminated. See below 2 pieces of the apron. I still have to cut them to exact length.
I am going to attach the router either today or tomorrow and cut out the top and inner area for the glass. The sliding mechanism(orange colored UHMW??) works well once it is fitted into the track. Good news is the tight fit also cuts down on any "slop" in the movement.

Jim

233793

[Kent A Bathurst]

Cool. The "slop" factor was what I was wondering about.

I have in the backlog [the cobbler's children's shoes backlog] a Limbert double-oval table out of some very nice QSWO. VERY nice. While this jig is some bucks, it could be worthwhile for that one - there is a definite pucker factor involved, and the video makes it look like you will get a dead-nuts finished piece.

If you can, maybe you would let us know how it works with the router bolted on, and cutting the top? Sounds like it should work well, but would be nice to get your evaluation.

Thanks, Jim.

[Bruce Wrenn]

Bruce, why do you recommend a quarter template? Doesn't seem any easier than making a full one...?Why? You have to make four sections that are the exact same. Chances of that happening, almost zero, IMHO. By by flipping template all four WILL be the same. Commonly done in patterns that are the same left to right.

[Prashun Patel]

But using two points to scribe an ellipse should result in a perfect pattern, no? This would allow me a sing seamless template to which I can route.

[Jeff Bartley]

Prashun, I saw the title, read the post, had the song go through my head....never thought I'd see a ref to Echo & the Bunnymen here! I too was a teenager in the 80's.
My vote is a full template out of hardboard......but I'd probably adhere it to the workpiece with a few pieces of carpet tape. Just don't use too many, it can make removing the template very difficult. Jeff

[Prashun Patel]

Jim, I've decided to make a curved apron as well (laminated). I'm going to use bendable poplar for the core with an outer veneer.

I have no prob making a bending form. However, how did you square off the ends accurately so they'll mate up perfectly with your legs? I can't think of the best way..

[Jim Tobias]

Prashun,
I haven't cut my aprons to length yet, but plan to do so on the tablesaw. I plan to mark them on the layout that I have drawn using jig and then fit them )with legs. After laminating the aprons(bendable plywood and an outer veneer of 1/8" maple,
I scraped off the glue(a lot of it from lamination process) and then jointed one edge on jointer(keeping outside face flat to the fence). Then I used that face as a reference and cut the aprons(very carefully) to width on the tablesaw.
I used a duplicate of the male lamination form to cut the leg ends square on the tablesaw. I've been working on veneering the exposed curved leg edges (laminations) with veneer so as to give me a smooth surface to spray the black lacquer without any lamination lines showing through. I am going to use the 50mm dominoes for joinery so getting the mortises cut square will also be a challenge.
I'm confident I will probably have to do a little "custom shaving/fitting at some of the joints as this many curved parts are not likely to all be exact.

Jim

[Prashun Patel]

Thanks. I am still unclear how to cut a perfect 90 on the ends of the aprons on the tsaw since there won't be a flat face. I guess I have to build a Cradle to hold it at the right angle. I really hate cutting and milling thin laminations for this kind of stuff, so I'm getting some bendable poplar from curvolutions. I will just put an ash veneer on the outside.

[Jim Tobias]

Prashun,
You could use the square sides of the laminating/bending form as your square reference (see below). Excuse the lack of detail on the drawing, but it was quick. I thought about using this option but prefer not to cut up/shorten my bending form as I may want to use it again. I'm going to try laying the aprons out on the full sized drawing(again done with the ellipse jig) and mark the aprons at the intersection points on both sides of the apron. Then line it up with the table saw blade and clamp it to the sliding Incra sled(with the flat jointed edges on the sled) and cut. Again, I may end up "custom fitting each joint a little, but I think it will work that way.
I haven't cut yet so I am open to any ideas.

Jim

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[Prashun Patel]

I'm going to use the bending form as a jig for the tablesaw I think. In fact, since the form will line up perfectly with the blade, I don't think it will have to be shortened at all.

[Jim Tobias]

Sounds like it will work.
When I make a bending form, I usually make it a little oversized. By "shortening the bending form", I meant that usually at the very end of the form your laminations might not be quite as tight and therefore you may need to trim back and in doing so, you would be cutting your form a little shorter.
Let me know how this all goes as I am always looking for improved ways to solve a problem.

Jim

[Jim Becker]

Thanks. I am still unclear how to cut a perfect 90 on the ends of the aprons on the tsaw since there won't be a flat face. I guess I have to build a Cradle to hold it at the right angle. I really hate cutting and milling thin laminations for this kind of stuff, so I'm getting some bendable poplar from curvolutions. I will just put an ash veneer on the outside.

Jig-up to hold the workpiece(s) where they need to be to make your cut.

[Roger Feeley]

I've never tried this but I wonder...

We all know that you can make an elipse with two pins and a string. but two pins and a string would be too weak and stretchy with a router. I wonder if you could use a router with two bolts and some 1/16" aircraft control cable. That stuff just plain doesn't stretch. You would have to build an auxiliary base to act as sort of a pulley and the bolts would have to have pulley wheels around them too. The ends of the cable would have to be fixed to the router base so you wouldn't have to deal with a lump where the two ends join. It could work...

[Prashun Patel]

It seems that it would be too easy for the router to slip and ride into the ellipse. This might work well for cutting an elliptical hole, but I'm not sure it'd be that easy to control when cutting an elliptical 'plug'.

[David Epperson]

I've never tried this but I wonder...

We all know that you can make an elipse with two pins and a string. but two pins and a string would be too weak and stretchy with a router. I wonder if you could use a router with two bolts and some 1/16" aircraft control cable. That stuff just plain doesn't stretch. You would have to build an auxiliary base to act as sort of a pulley and the bolts would have to have pulley wheels around them too. The ends of the cable would have to be fixed to the router base so you wouldn't have to deal with a lump where the two ends join. It could work...
Tried it. The results were not pretty. Even with steel cable there was too much give in the set up and the router wants to get out of alignment. I ended up just building a set of slides and making an ellipse machine base. I set it up like a lazy susan and used in on my router table.

[glenn bradley]

http://zo-d.com/stuff/squares-and-measuring/how-to-use-a-framing-square-to-draw-an-ellipse.html

Cut out ply template, bandsaw to rough shape and route to finish ;-)

[Van Huskey]

Just cut a huge cone then slice out the ellipse you want... :D With a big enough bandsaw with a tilting table and your golden, as long as you have a big enough chunk of wood. See it is all about the bandsaw, just three cuts, no need to measure and draw and cut and shape and and and.

[Jim Underwood]

If you were nearby, I could cut an ellipse template with the CNC router for you... Of course the boss would want $$$ for it. :o

[Kenneth Speed]

Bill Huber's suggestion is a good one and I think it's worthwhile to learn or relearn that method. Using the framing square and pencils approach is also a good way to draw an oval. I think the Popular woodworking method is useful because one can use it to make small ovals such as drawer face inlays and paterae while the framing square method is the wrong scale for those things it works fine for table tops and the like. Why buy a when you're only rarely going to be making ovals?

Ken

[Prashun Patel]

I just finished the coffee table. Thanks for the help and suggestions. Learned a lot!!!

http://www.sawmillcreek.org/showthread.php?191800-Elliptical-Ash-Coffee-Table&p=1980625#post1980625