Floating top?

[Adnick]

Building a new tool cabinet, the base/stand for it is 66" long, and want it to float above the legs on each end. The concept it's that the apron/rail will have a gentle curve, higher in the middle to achieve the floating effect, so arched to each leg....

What's the best way to draw out a slight radius over a 66" length? String is a bit imprecise at that length, but a trammel for that distance seems impractical, or am I just not thinking about this right?

Thanks for any input,
Andy

[Harthag]

Not sure if this is helpful, but what about making a template for half the overall length, and flipping it over.  That would at least ensure symmetry.

[Phil S.]

You could use a fairing batten as used in boat lofting, basically a thin stick you bend to the shape of your curve, like so -



Clear even-grained wood helps in getting a fair curve (i.e. one without a lot of humps and bumps in it).  You can use a piece of string, tied from end to end, to get the bow you want or bend the batten around brads tacked at 3 points on your curve.

[Derek Cohen]

Thickness a batten a little over the length you need, drill a hole at each end, and connect with cord. Tighten/loosen the cord for the curve you want.

Note that a even thickness will create a different curve from a tapered thickness batten.

Draw in the curve, then use one half of this as a template for the full curve (if you wish to keep it symmetrical).

That is what I did in my Sofa Table build.





Regards from Perth

Derek

[hbmcc]

You could make a trammel 30-feet long like an author-builder did in FWW. Personally, I would use a fairing batten. I have access to the straight grain resources right now. You would want to use something besides a handsaw to cut it--a lot easier on a table saw or RAS.


Or, or.... do what the oldtime ship builders did. Do a proportional expansion of an arch, then connect the dots.

But, a batten is still a lot easier. Unless it is too short for the full length. Then, the arch expansion will be easier.

[ez-duzit]

I use a fairing batten, pushed against a pair of lead weights, to transfer 1/2 of a fair curve (always looks better than a true radius) onto a piece of tempered Masonite, which I cut and tuneup by hand/eye. Then I transfer mirror images of this to the workpiece, using the Masonite as a router template or simply as a pattern.

[Adnick]

Thanks everyone, I've used a string batten for shorter curves and it worked well....splitting it up might be the best option.

Will let you know how it turned out.


Thanks again,
Andy

[JimReed@Tallahassee]

The beauty of a trammel is that it has almost infinite length and is easy to make. Just fasten a pencil to a long furring strip and pound a nail slightly through the other end. Of course, this is easier if you have a trammel set that clamps on the edge of the beam. I once used my edge clamping trammel set and an 8 ft section of furring strip to describe an an arc for a bookcase top.

[Adnick]

Jim, appreciate the advice....

Andy

[Steve Hamlin]

Use a long compass.
http://www.homemadetools.net/homemade-long-compass